MIGRATION
1. Problems of Mediterranean-Saharan migration. R. E. Moreau. 1961.
Ibis, 103a(3): 373-427; 103a(4): 580-623. Two vast and largely land-
locked seas, the Gulf of Mexico and the Mediterranean, pose problems for birds
migrating back and forth between holarctic and tropical regions. Many European
ornithologists have felt that such birds tend to detour around the widest parts of
the Mediterranean. The most commanding voice of dissent for more than two
decades has been that of R. E. Moreau. Now in a 99-page synthesis, he reviews
the reasons for his deepening conviction that the smaller migrants usually cross the
Mediterranean on a broad front.
The Gulf of Mexico exceeds the Mediterranean in north-south expanse but is far
inferior in east-west dimension. At first glance the average trans-Gulf migrant
would seem to risk more to gain less than the average trans-Mediterranean migrant.
Moreau demolishes this notion. Most crossings of the Mediterranean are closely
linked with at least a 900-mile traverse of the Sahara, where to land without shade
is to court death and where the oases are like "a few dozen teacups" scattered in a
football field. Worse still, spring migrants must expect head winds everywhere
over the desert unless they fly northeastward, at high altitude. Moreau believes that
most adopt the diagonal course, which though much longer in mileage should
average much shorter in time. He rates the journey from central African latitudes
to Europe "potentially the morst arduous to be performed regularly by a mass of
land-birds anywhere in the world." In spite of the greater distances involved in
migration across the Banda Sea, he may be right. Certainly his conclusion that
trans-Saharan migrants must be able to contint_e for 2 to 23/_, days without refueling
well exceeds the most pessimistic estimates for trans-Gulf passage.
A belt of vegetation varying in width from more than 200 nailes to only a few
nailes intervenes between the Mediterranean and the northern edge of the desert.
Here spring migrants from south of the Sahara can pause before launching out again
on another nonstop flight, this time over the sea. Observations of grounded migrants
all along this belt of vegetation in spring are the core of the evidence that most
small bird traffic between Europe and Africa is on a broad front. Moreau assembles
the data from 8 sectors of the southern Mediterranean coast for 57 species of non-
soaring land birds, nearly all the birds of this sort that breed wholly or partly
within the same longitudes as North Africa and winter wholly or almost wholly
south of the Sahara. He presents these data both in a series of species accounts
and in a semigraphic table somewhat reminiscent of the table of relative abundance
once provided for the Gulf of Mexico (see Bird-Banding, 29 (1): Review 5).
Though migrants are obviously much more numerous in fall than in spring, the
volume of migration usually appears much greater at the latter season to field ob-
servers along the northern shores of the Gulf of Mexico. Such too has been the case
in Moreau's central sectors -- Algeria, Tunisia, Tripoli, and Cyrenaica. But both
to the east and to the west of these sectors, the seasonal disparity is not so great.
The general situation suggests that most migrant with adaptations for the difficult
spring flight across the Sahara have ample reserves for a nonstop passage from
Europe to their wintering grounds in autumn, when the air flows are more favorable.
This assumption provides an alternative explanation of much of the evidence for
such phenomena as "loop migration" and the European migratory divide.
Moreau is keenly aware how delusive counts of grounded migrants are. Repeatedly
the reader senses loopholes in reasoning and just as repeatedly finds them antici-
pated. The process has a disarming quality, but it does not remove the difficulty
that ambiguous data are almost the only materials available for the construction of
hypotheses regarding the immense subject to which Moteau has here devoted so
much labor, skill, and insight. He does not pretend otherwise. He frankly states
that most of the views he expresses are entirely provisional.
The thought may arise that the birds seen along the central sectors of the south
shores of the Mediterranean could be the ecologically concentrated product of drift
from routes lying well to the east or west. Moreau's reasons for rejecting such an
explanation are not conclusive, but they are extremely interesting. He cites 51
records of small transients recovered in subsequent seasons at the locality in Tunisia
where they were banded. Such precise adherence to individual routes suggests to
him a system of navigation accurate enough to place rather rigid limits on drift.
-- R. J. Newman.
2. Movements at sea between southwest Iberia and northwest Africa. C. H.
Fry. 1961. Ibis, 103a(2): 291-293. A eview of current papers and published
notes offers a means of making a vicarious trip from west to east through the Medi-
terranean region, a journey that Moreau's latest analysis renders extremely opportune.
The tour begins on 21-22 September 1959 in the Atlantic with Fry's observations
aboard a ship sailing straight from the Canary Islands to Cadiz.
While east wind were blowing, the vessel transected a bird movement that
appeared 'sufficiently vigorous and directed" to be an extensive broad-front migra-
tion. Fry identified approximately 140 land birds of 16 species. Half the species
were Old-World warblers, but more than half the individuals were Turtle Doves
(Streptopelia turtur). Some birds that came aboard stayed long enough to be
carried back 100 miles northward. A few permitted capture. Yet Fry considered
none unduly exhausted. The data add to the proof that, on occasion at least,
numbers of migrants pass from Iberia to Africa over oceanic courses west of the
entrance to the Mediterranean. -- R. J. Newman.
3. Further observations on migration in southwest Iberia. C. J. I--Ienty. 1961.
Ibis 103a(1): 28-36. Henty momentarily takes us backward from Cadiz to Cape
St. Vincent, Portugal, the westernmost extremity of the coast of southern Europe,
well east of the Canaries and even more to the east of the farthest bulge of Africa
into the Atlantic. Mist-netting operations on the Cape in the autumn of 1957
(Bird-Banding, 30(3): Review 2) had revealed the presence of many small noc-
turnally migrating transients. Now in the following fall, Henty and six helpers
tried to determine whether similar concentrations occur all along the southwest
coast of the Iberian Peninsula.
The results are difficult to evaluate. Mist-netting at the Cape in 1958 yielded
448 birds, far fewer than in 1957, and revealed no pronounced migration waves.
At other points on the coast the nets were ineffective. The only simultaneously
studied stations were the Cape and Quarteira, about 50 miles away. Since the data
are mist-netting results in the one case and counts of grounded migrants in the
other, no direct comparison is possible. Subsequently the party moved systematically
eastward along the coast, with stops of several days at three other well-spaced
localities, the last of these being Tarifa at the Straits of Gibraltar. A table shows
that the number of grounded night migrants of eight species recorded at Quarteira
and Isla Christina, about 45 nailes to the east, were very similar. The other localities
seem to have been less productive. Grounded night migrants were particularly
scarce at the Straits. Henty's own conclusion is that "these observations . . . indicate
that autumn migration through S. W. Iberia is on a broad front."
Little raptor movement occurred in south Portugal or on the Coto Donaria, north
west of the Straits), but concentration at Tarifa was marked. Small easterly
movements of swallows were visible along part of the southwest coast of the Penin-
sula, but these did not lead to a stream along the length of that coast. The inference
is that the birds were going out to sea somewhere along the line. Much larger
flights near Tarifa seemed to originate from inland. -- R. J. Newman.
4. On the birds of the south of Spain with special reference to migration
(spring 1959). Sobre aves del sur de Espafia con especial referencia a migraci6n
(primavera 1959). P. P. Feeny. 1960. Ard:ola, 6(1)' 125-150. (With English
summary). A change of season finds our review tour still stalled in western Spain.
Feeny and the other members of his expedition, in the field from 26 March to 19
April 1959, concentrated attention on the stretch of coast between Cadiz and
Gibraltar. There they did not ,neet with the large number of nocturnal migrants
anticipated, and no "waves" developed. Feeny attributes the paucity of observations
to generally good weather, which encouraged birds to continue on inland before
alighting. As in autumn, the observations of raptors were almost exclusively confined
to the Straits. Prominent among diurnal migrants were swallows (Hitundo rustica),
which usually flew low, and Bee-eaters (Meriops apiaster), which usually flew
higher. The large numbers of shore birds in the Guadalouivir Valley suggested
that this valley may be the principal migratory route for such birds in southwest
Spain. A systematic section gives brief accounts for 74 species. -- R. J. Newman
and F. J. Rolle.
5. Migration from Morocco into southwest Spain in relation to weather.
I. C. T. Nisbet, P. R. Evans, and P. P. Feeny, 1961. Ibis, 103a(3): 349-372.
"Under these circumstances [clear, ,noonlit nights], the reviewer finds it hard to
understand why, after journeying all the way to Portugal expressly to study migra-
tion, the party made no effort to secure direct information on nocturnal migra-
tion by watching the moon -- information without which the other data remain
ambiguous." The quotation is from a 1959 issue of Bird-Banding (30 (3): 187).
Now, members of another party have used moon-watching data as the foundation of
a study of spring immigration from Africa into the Iberian Peninsula.
Interest centered on the number of migrants using the shortest crossing over the
Straits of Gibraltar in comparison with the number flying over the greater stretch
of ocean just west of the Straits. During approximately 21 station-hours of simul-
taneous lunar observation spread over 5 nights, computed migration traffic at Tarira
(terminus for the minimal crossing) exceeded that at San Lucar de la Barameda
(terminus for a longer, more westerly crossing) in the overwhelming ratio of 33 to 1.
The calculated nightly heading of nocturnal migrants crossing before the ,noon at
the Straits was usually between north and north-northeast, but was northwest on
a night when clouds hid the stars. As in radar studies, where no other method is
possible, these headings were derived on the still debatable premise that night
migrants never compensate for drift. By frequently permitting judgments regarding
both track and heading, moon watching provides a possible observational test of
this assumption, but no one has yet made such a test.
A feature of Moreau's paper not mentioned in Review 1 is his calculation,
based on population density, that the number of trans-Mediterranean migrants should
average roughly 2,000 per mile of front per day during a 2-month spring season.
The stated figure for the period of moonwatching at the Straits is several thousand
per hour. The actual hourly mean, calculable from the data given, barely exceeds
2,000; but even the disproportion between 2,000 birds per day and 2,000 birds per
hour, sustained for 6 hours, remains immense. The ways of explaining the differ-
ence are several. The simplest is to assume that many birds detour around the
Mediterranean after all. Another is to doubt that five nights of experience at any
locality at an optimal time can lead to a reasonably close approximation of the local
mean for an entire spring.
Misbet, Evans, and Feeny favor neither of these extremes. They suggest instead
that drift and topographic lines of influence ,nay combine to concentrate migration
that began on a broad front. The African shoreline slants northeastward as it
approaches the Straits. If night migrants can distinguish between land and sea,
as seems probable on moonlit nights at least, reluctance to launch out over the ocean
might divert many of them toward the Straits. The radar data of Lack from Britain
discourage such an idea; but these data, obtained in a special insular situation, do
not necessarily represent the reactions of nocturnal migrants in general in other parts
of the world. The possible role of drift is in delicate balance. It must have been
strong enough to nudge trans-Mediterranean migrants toward the Straits, yet too
weak to carry them beyond. Really powerful east winds seem to be able to push
migrants to the Atlantic crossing, west of the Straits. As evidence of the latter
effect, the authors point out that grounded migrants in numbers were found west
of Trafalgar only during east winds. They also cite instances of drift on the part
of small diurnal migrants and probable instances involving raptors.
Tables compare the varying amounts of grounded migration on the Spanish coast
with weather variables in Morocco. When statistically analyzed, the migration
quantities showed correlation with dry weather and rising night temperature in
Morocco but not with high temperature per se. -- R. J. Newman.
6. Notes on the migration of swallows in southeast Spain. Nora sobre mi-
gracion de hirundinidos en el SE de Espafia. Jos J. Tato Cumming. 1960. Ardeola,
6(2): 364-366. The observations, dating from August 1959 through the first days
of October, mostly concern movements of Hitundo rustica near the shores of the
small embayment of the Mediterranean known as the Mar Menor. The author
pictures the movements as being most strongly influenced by topography -- by
mountains and seas that channel low-level flight. He considers convergence of
topographically determined flight lines to be the reason why great numbers of
swallows congregate at certain favored resting points in southeast Spain.
Though deemphasized, meteorological factors were involved in some of the events
described. Almost without exception, Barn Swallows followed the trend of the coast
of the Mar Menor as long as it remained southwesterly. Where the shoreline swerves
suddenly eastward, they usually retained their original direction and cut across the
base of the Cabo (Cape) de Palos; yet on one occasion, when a brisk warm breeze
was blowing from the southeast, they turned into the wind and skimmed over the
water in the direction of the Cape. Once when a storm front had crossed their path
farther to the west, the birds could be observed returning. And the irregular presence
of Delichon urbica, Riparia riparia, and/lpus apus in the flights of Hirundo rustica
coincided with bad weather.
The author visualizes a funneling of small migrants in general toward the short
crossing at the Straits of Gibraltar. But he speaks of a tendency of the larger birds
seen from his vantage point to head south or southwestward, directions that if
maintained would carry them out over a much wider expanse of sea.--R.J. Newman.
7. Notes concerning migrants observed during a trip to Spain in the spring
of 1959. Nora sobre migradores observados durante un viaje por Espafia
(primavera 1959). R. Lvque. 1960. Ardeola, 6(2): 348-351. These notes,
frankly a byproduct of a more general exploration, understandably contribute little
to the solution of migration problems, though they cover a period of more than 5
weeks, and a wide range of territory extending all the way to France. Seven of the
14 species accounts deal with water birds. Most of the nocturnally migrating species
encountered are merely listed, without data. -- R. J. Newman.
8. Observations concerning migration at Beauduc, Camargue, in the springs
of 1959 and 1960. Observations sur la migration 3 Beauduc, Camargue, aux
printemps 1959 et 1960. (With English summary.) Peter Hope Jones. 1961. Alauda,
29(2): 118-133. At last this series of reviews leaves Spain behind and reaches
the Camargue. Though this "island" in the Rhone Delta is ornithologically the
most celebrated region in France, few previous data exist concerning the migration
there. Jones devoted a total of 3 months to his investigations, which were con-
centrated in a small area near the Mediterranean shoreline. Most of his discussion
concerns diurnal migrants, even though their numbers were usually so light that
much watching was required to produce even modest dividends. Two of the three
heaviest visible flights began immediately after the passage of storms. Though
strong southeast and east-southeast winds were involved, Jones suspects that the bad
weather moved in from the sea toward the coast more slowly than migrants normally
fly and that the birds tended to accumulate behind the storm line. On the third
occasion a strong head wind induced many normally high-flying birds, particularly
swifts, to descend low enough to be seen. Most day migrants flew over the area on
a north-northeast bearing, perhaps in response to a diversion line running in this
direction. Their track indicates that these birds came in from the sea, and a table
gives records for 20 species actually seen arriving from over the water. A rather
surprising inclusion is the House Sparrow (Passer domesticus).
The paper implies that considerable time was devoted to the mist-netting of
night migrants and to the banding, weighing, and measuring of the birds caught.
The data from this phase of the work are reported in less detail. In calm weather,
most of the catches of nocturnal migrants took place early in the morning; but when
massive influxes of new arrivals were under way, results remained good all day
long. Such influxes most commonly occurred 1 or 2 days after strong north or
northwest winds had died away. On the northern coast of the Gulf of Mexico, in
contrast, the big landfalls of night migrants are most likely to take place while
northerly winds are blowing. -- R. J. Newman.
9. Autumn migration in Greece. P. P. G. Bateson and I. C. T. Nisbet. 1961.
Ibis, 103a(4): 503-516. Recent regional reports on Mediterranean migration skip
over Italy to Greece, where two parties worked from 18 August to 11 September
1960 and obtained the first lunar counts of birds ever made in that country. Most
of Greece is a peninsula surrounded by wide expanses of sea. The observation there
of numbers of transients, particularly in the southern part, would be unlikely unless
these migrants were about to undertake transmarine passage. In this connection,
the 23 hours of nearly simultaneous moon-watching in northern and southern Greece,
representing 5 nights, provide considerable insight. Though the data are objective,
they can be expressed in various ways. For convenience, the ways employed on this
review will not always be exactly the same as those of the authors.
In both sections of Greece, the main flight direction was very close to south. In
other words, most of the birds were heading toward a direct crossing of the Mediter-
ranean. In the northern section, the flight had a small eastward component that
could be regarded as part of a circum-marine movement toward Turkey; but it also
had a stronger westward component difficult to explain in terms of routes. The
amount of migration according to lunar criteria was abut 78 percent as large in
southern Greece as in northern Greece. If only the southward-moving portions of
the flights are compared, the percentage remains appreciably inferior. But the total
computed migration for the southern stations exceeds the southerly migration at the
northern stations by a wide margin. A north-northeast component at the southern
stations accounts for part of the discrepancy. A total of 42 hours devoted to a search
for resting night migrants produced hourly means of 20.3 for northern Greece and
15.7 for southern Greece. The 77 percent relation between these figures is remark-
ably close to the percentage derived from the lunar counts. The sum of the hourly
means for the 10 hours of the night when lunar watches were made is 10,170
birds, 21/2 times Moreau's estimate of the average number of trans-Mediterranean
migrants that should cross a mile of front in a 24-hour period in fall. Even if one
deducts a liberal allowance for the birds that were not flying in southerly directions,
the 10-hour figure still remains double Moreau's 24-hour estimate. Thus the state-
ment by Bateson and Nisbet that their average migration density "is of the same
order as the average density calculated by Moreaif' should perhaps not be construed
too literally.
A feature of the paper by Nisbet, Evans, and Feeny not mentioned in Review 5
is that moon-watching at Tarifa revealed no major variations in the density of migra-
tion with the time of the night. The present paper makes a similar claim with
regard to the results between 8 p.m. and 2 a.m. Actually, except for an aberrantly
high density in the hour following midnight, the figures for the whole 10-hour
period closely fit the smoothly ascending-descending pattern of hour-to-hour change
exhibited by fall migration in America. In fact, 261/2 hours of observation have
seldom before reproduced the pattern with such fidelity. -- R. J. Newman.
10. Notes on autumn migration at the Bosphorus and in the Aegean.
D. K. Ballance and S. L. B. Lee. 1961. Ibis, 103a(2):195-204. The Aegean is a
broad northward extension of the Mediterranean interposed between most of Turkey
and most of Greece. It connects eventually with the Black Sea by way of the
Dardanelles, the lake-sized Sea of Marmora, and the straits called the Bosporus. In
August and early September 1959, four observers in two parties visited all these
places to look for concentrations of night migrants and to gather the first systematic
notes on southward daytime migration in the area so early in the season.
They found only moderate numbers of either nocturnally or diurnally migrating
passerines. Among their highest counts were: 40 Spotted Flycatchers (Musicapa
striata), Bosporus, 28 August; 80 Willow Warblers (Phylloscopus trochilus),
Bosporus, 2 September; and a flock of 200 Yellow Wagtails (Motacilla /lava),
Kiigiik, Cekmece, 1 September. Prominent among small nonpasserines were Meriops
apiaster, and the inevitable Streptopelia turtur. Observations of soaring birds were
more numerous. Tables give counts for 14 species of storks and raptors seen
"migrating East or S.E. in the Bosphorus area," on 20 dates. How many birds of
these species were observed migrating in other directions is not clear. The figures
favor the conclusion that the autumn movement of such birds is inhibited by strong
northeasterly winds. White Storks (Ciconia ciconia) outnumbered the next most
abundantly observed species (Pernis apivorus) more than 3 to 1. This result is sur-
prising, since two long-time observers at the Bosporus writing 90 years ago had
never witnessed an autumn passage of White Storks there. Other highlights in
the water bird category were the arrival of seven herons (Ardea cinerea, Egretta
garzetta) flying wrong way into a strong northeast wind, the unprecedentedly large
number of Little Gulls (Larus minutus) noted on the Bosporus, and the first Eastern
Mediterranean records of the Arctic Tern (Sterna paradisaea). -- R. J. Newman.
11. Spring migration of raptors in Bulgaria. Anthony Lambert. 1961.
Ibis, 103a(1):130-131. Bulgaria borders the Black Sea. It is separated from the
Bosporus only by a relatively narrow strip of Turkish territory. So these spring
notes provide a timely comparison with the report summarized in the preceding
review.
Observations in late March 1960 of large flights of hawks along with Rooks,
cranes, storks, and herons in the Burgas region of eastern Bulgaria suggest to
Lambert that large birds of prey migrating across the Bosporus follow the coast of
the Black Sea as far as its westernmost point and pass into Europe through the east-
west valleys of the "Balkan Corridor," which lies along the south side of the Balkan
Range. Additional observations indicate that terns, bee-eaters, doves, and shrikes
may also use the same route. Such marked responsiveness of the smaller birds to
details of topography seems at variance with the concepts of Moreau. -- Stuart L.
Warter.
12. Migration through Cyprus. W. R. P. Bourne. 1960. Proceedings Xll
Ornithological Congress: 127-132. This synopsis of the findings of the reactivated
Cyprus Ornithological Society deals with the most easterly island of the Mediter-
ranean, situatec "where there is a local concentration of the great migration between
the Palearctic and Ethiopian regions as birds fly around the eastern extremity" of
that sea. The species treated are many and diverse, and the sources of evidence are
several -- banding recoveries, observer networks, moon watching, and radar.
Large numbers of migrants visit Cyprus annually. They occur in greatest numbers
in spring, probably because conditions then are most conducive to lingering. The
banded birds recovered there come from places as far apart as Britain and Moscow,
but the bulk of the passage migrants are from the northwest rather than the north-
east -- a circumstance suggesting that transients from the latter source tend to
travel overland. Radar returns have created the impression of immense flights of
small birds, moving over the area too high to be seen, mainly during the first half
of the night just as in the case of lunar silhouettes in America. But maximal counts
of birds passing before the moon at Cyprus were only six per hour in fall, three in
80 minutes in spring -- poor by United States standards yet sustaining almost exactly
in their modest way the New-World moon-watchers' experience that twice as many
birds go south in autumn as return in spring. Whether radar has exaggerated the
volume of migration over Cyprus or lunar observation has unduly minimized it
are questions that still remain to be decided. From the ordinary field observer's
viewpoint, Barn Swallows (Hirundo rustica) have made up a large part of the
transmarine migration visible by ordinary means, just as in many other places on
many other occasions. In line with previous findings, their "biggest coastal passage
occurred with relatively unfavourable weather conditions, and the smallest coastal
passage occurred when birds were going out to sea in greatest numbers high
overhead . . ."
On the basis of his general summary, Bourne ventures the following conclusions:
that "under the stable weather conditions which prevail in the Mediterranean area
the majority of small birds seem to fly higher, and pay less attention to topography
than they do in northern Europe"; that "many birds must make a definite detour
around the Mediterranean, avoiding the central Mediterranean-Sahara crossing to
Africa by passing through the Middle East"; and yet that "different species seem to
respond to the necessity to cross the Mediterranean and desert zone in different
ways." Presumed differential behavior in the last regard is not taxonomically
separated. He illustrates it by contrasts among closely related Old-World warblers,
as well as by contrasts among large "soaring" birds -- herons and cranes, harriers
and falcons. -- R. J. Newman.
13. Some land birds noted at sea between Mombasa and the English Channel.
R. Charles Long. 1961. Ibis, 103a(1): 131-133. Fittingly, our review tour, which
began with an ocean voyage, ends with an ocean voyage. Long's terse ornithological
log of the latter journey, 27 April - 17 May, lists 34 nonpasserine land birds of 7
species and 113 passerines of 6 species. No land birds at all appeared while the
ship was in the Indian Ocean, off the east coast of Africa, and only a very few
were noted during the passage through the Gulf of Aden and the Red Sea. In
contrast, 80 Yellow Wagtails (Motacilla flava), including examples of 3 subspecies,
landed on the vessel on May 8 in the mid-Mediterranean, southwest of Greece, and
24 European Redstarts (Phoenicurus phoenicurus) came on board on May 10, off
the coast of Italy. Eight Turtle Doves (Streptopelia turtur), 2 Barn Swallows
(Hirundo rustica), and 2 Yellow Wagtails were the only birds noted beyond the
Straits of Gibraltar. All in all, the present results are not as impressive as those
of Fry from west of the entrance to the Mediterranean (Review 2).
Considered in retrospect, the material summarized in the preceding reviews appears
to be as chaotic a mixture as the jumble of land and water from which it came. One
can understand why Moreau placed such emphasis on events along the more regular
southern shore of the Mediterranean. -- R. J. Newman.
14. Studying migration by moon-watching. I. C. T. Nisbet. 1961. Bird
Migration, 2(1): 38-42. with figure facing p. 44. Replicated moon-watching is
one of the main means Moreau has suggested for the eventual solution of the
immense migration problems associated with the Mediterranean and the Sahara.
Dr. Nisbet has been a major force in initiating such investigations (see Reviews 5
and 9). Here he promotes this line of research in another way by making readily
available to the European reader a discussion of the principles of migration study
by moon watching, its field procedures, processing phase, advantages, disadvantages,
and applications. As a stringently brief rsum of a complex subject, the treatment
is in general excellent. But the many American migration students already familiar
with the subject will be most interested in details regarding which Nisbet expresses
views that differ from the previous consensus.
For example, Nisbet says that high-powered binoculars are better for moon-watching
than telescopes, since they cause less eyestrain. Yet repeated experience has shown
that a single observer using a 20-x spotting scope can watch the moon 40 minutes
out of every hour (20 minutes with each eye) from dusk to dawn without undue
visual fatigue. The use of a polaroid filter to reduce the glare of the full moon
and of an eyepatch to rest the unemployed eye has been helpful in this regard. But
one may doubt seriously that under any circumstances, an observer could stare with
both eyes at the moon for 40 minutes out of every. hour for 12 hours as comfortably.
Direct comparison tests between 20-x scopes and 10-x binoculars, which Nisbet calls
not too small, have indicated that the larger instrument is at least 40 percent more
effective. His own preference for instruments of less than 20-x magnification is
perhaps one of the factors that has convinced him that "small birds cannot be seen
at ranges of much over a mile." In actual trials in Louisiana, a mounted Parula
Warbler viewed against the daytime sky remained clearly visible at a distance of
a mile through the 20-x scope and was still discernible at a mile and a half. A
warbler of the same small size thrown into sharp relief against the moon and passing
far above the layer of greatest atmospheric interference, should remain visible at
even greater distances. Such common migrants as thrushes, tanagers, and the like
-- much larger but still classifiable as "small" migrants -- should be perceptible
nearly twice as far away as the Parula.
The counsel that "it is wise to avoid places where birds might perhaps be chan-
nelled by topographical features" needs modification. One of the greatest opportuni-
ties of moonwatchers working in cooperation with other moon-watchers is their
chance to compare results at such places with results at adjacent localities where no
channelling effect is to be anticipated.
As an experienced practitioner of both the moon-watching and radar methods of
migration study, Nisbet is eminently qualified to compare the two. As comparative
drawbacks of lunar study, he lists the small area covered, the limitation to clear
weather and to only a few nights each month, and the mathematical labor required
to obtain statistically valuable results. As comparative advantages, he points out
that the moon-counts can be conducted anywhere by anyone and that they provide a
direct and accurate estimate of the number of birds in the air, whereas radar can
at best measure only the number of flocks. The veteran moon-watcher might take
some exception, but he still would certainly agree that both methods, judiciously
applied, can work well together toward a solution of migration problems. --R. J.
Newman.
15. Flight speeds of some small birds. Oliver P. Pearson. 1961. Condor,
63(6): 506-507. Moreau's forthright conclusion that a migrant embarking on a
flight across the Sahara must be prepared to remain aloft for 50 to 60 hours raises
crucial physiological questions. All the provisional answers that can be given to
these questions at present go back for their ultimate basis to measurements Pearson
made a decade ago of the metabolic rate of hummingbirds hovering in a bell jar.
By making several assumptions -- that the energy requirements of straightaway
flight approximate those of hovering, that hummingbirds migrate at an air speed of
50 mph, and that their fuel reserves do not exceed 1 gram of fat--- Pearson himself
calcul'ated the maximum range of nonstop travel as 385 miles, considerably less
than the distance across the Gulf of Mexico. Later Odum and Connell (Science,
123: 892) found Ruby-throated Hummingbirds with 2.1 grams of fat, seemingly
more than enough for a direct Gulf crossing.
Recently Pearson released Allen's Hummingbirds in a large culvert. As they
emerged, a motion-picture camera photographed them against a 1-inch grid and,
by means of a mirror arrangement, recorded their distance from the grid. The flight
speeds shown by the film were only 23.8 and 18.2 mph, less than half the speed
originally assumed. This drastic reduction in velocity neatly cancels the gain in
estimated cruising range conferred by the doubling of the assumed fat reserves. So
once again experimental evidence seems to discredit the ability of hummingbirds to
cross the Gulf.
But the new data by no means substitute certainty for uncertainty. That birds fly
at full cruising speed near the ground is open to question. That they would reach
such speed after flying only 30 feet in the semidarkness of a pipe is even more so.
Instructive in this connection are five species of fringillids that Pearson tested in
the same manner. He rated them at a mean of less than 17 mph, not much more
than half the mean for small migrating passerines indicated by radar. -- R. J.
Newman.
16. Lipid deposition in nocturnal migrant birds. Eugene P. Odum. 1960.
Proceedings XII International Ornithological Congress: 563-575." . . . the ratio
between energy required for everyday life [existence energy] and that required for
sustained strenuous work is of the same order of magnitude in horses and humming-
birds," says Odum. This conclusion provides a starting point for estimating the
nonstop flight capacity of an individual bird at a given time from its fat store of
energy. In doing so, Odum assumes that the requirements for sustained flight are
between two and three times existence energy and that migrants of the 10 species
on xvhich he is reporting tend to fly at an air speed of 30 mph. In the present study
he carefully extracted and measured the fat content of 308 birds of the 10 species,
all killed in Florida in autumn, while actually migrating, by collision with the
famous Leon County Florida TV tower (see Bird-Banding, 32(4): Review 35).
The ratings show variation from species to species. Presumably, the leanest
Scarlet Tanager (Piranga olivacea) carried enough fuel for at least 700 miles more
of travel, while the fattest White-throated Sparrow (Zonotrichia albicollis) had re-
serves for only another 400 miles. These findings fit prediction. The sparrow was
near its destination; the tanager was bound for South America. Less expected is
the great intraspecific variation among some birds that winter in the United States
sparingly or not at all, such as Red-eyed Vireos (Vireo olivaceus) and Indigo Bunt-
ings (Passerina cyanea). In both species, the calculated distance equivalent of the
fat reserve ranges from 50 miles to more than 1200 miles. But a majority of the
buntings are in the lower half of the range, and a majority of the vireos are in the
upper half. Two immature Scarlet Tanagers and an adult Bobolink (Dolichonyx
or3,zivorns), with 50 percent of the body weight fat, are the fattest birds yet recorded.
They should have been able to fly more than 1700 miles without alighting.
No adequate information is available regarding the extent to which palaearctic
migrants put on fat. Therefore Moreau in his discussion of the physiological
problems of a Saharan crossing has had to hypothesize on the basis of Odum's fat
determinations for American long-distance migrants. But he frankly points out
reasons why the conclusions about the possible lengths of nonstop flight must be
regarded as very doubtful. First, the foundation provided by Pearson is untrust-
worthy, since it is based on the average of readings that "varied from 165,/cc../g./hr.
to 23". Second, Odum has overestimated distances by failing to make allowance for
the effect of the different loads of fat the birds are carrying. The reviewer might
add that the time of collision introduces another unknown variable. Birds that strike
the tower after migrating most of the night have obviously already used up a much
larger part of their capacity for sustained flight than birds that are killed soon after
taking wing. -- R. J. Newman.
17. Premigratory hyperphagia in birds. Eugene P. Odum. 1960. American
Journal o/ Cli,ical Nutrition, 8(5): 621-629. Savannah Sparrows begin migration
before. and White-throated Sparrows usually after, their fat reaches a peak. Scarlet
Tanagers become extremely obese just prior to long flights. Odum uses these species
to exemplify three patterns of lipid deposition. The distinction between the first
two patterns is temporal and clear-cut. The third differs from the other two in the
vastly greater quantity of fat involved, but Odum does not sharply define its
qualitative relationships. Does the Scarlet Tanager start out with moderate fat
and later build up a maximal supply in some staging area? If so, its pattern as a
pattern strongly resembles that of the Savannah Sparroxv. Or does this tanager load
itself to capacity before ever starting to migrate? If so, its pattern is a larger-scale
repetition of the sequence in the White-throated Sparrow. Whatever the case, Odum
believes that the Ruby-throated Hummingbird exhibits pattern 3. Individuals have
now been found with as much as 2.6 grams of fat, which was 78 percent of the total
dry weight, the highest percentage recorded in any species.
The recognition of different patterns of fat deposition emphasizes the need for
experimental laboratory research on birds typical of all three. Work with the Bobo-
link, an outstanding long-distance migrant, has already begun at several laboratories.
,--R. J. Newman.
18. Fat-free weights of birds. C. E. Cormell, E. P. Odum, and H. Kale.
1960. Auk, 77(1): 1-9. This paper expands upon a finding mentioned in the pre-
ceding one. Weight minus fat is rather constant for all members of a species. Some
variation does occur with differences in basic body size due to sex, age, or race, and
in the postmigratory phase fat-free weight seems to drop somewhat below the year-
around mean. Still, a bander can closely approximate the true fat content of a
migrant by simply subtracting the average fat-free weight for the species from the
total weight of the bird. An actual trial has shown that he can do so much more
accurately than by the external criteria heretofore most commonly employed.
Through analysis of four subspecies of the Savannah Sparrow, the authors demon-
strate an almost exact correlation between variations in wing-length (usually a good
indicator of basic body size) and variations in fat-free weight. They state that
,generally the fat-free weight increases 0.30 grams for each ram. of wing length in
birds of small and medium size. But they could not incorporate these refinements
in their table giving fat-free weights for 13 additional species.
Odum and his colleagues have performed a great service to migration study by
opening a brand new field of investigation with a vast potential. Yet it is one that
field workers cannot exploit fully until ornithological laboratories provide more data.
Though we can count on Odum to be in the forefront of future progress, his deter-
minations will probably always be tinged with admitted geographic bias. A pressing
need is for physiologists in other parts of the United States to venture down, the
path he has pioneered. -- R. J. Newman.
19. Flight energy and estimated flight ranges of some migratory birds. E.P.
Odum, C. E. Connell, and H. L. Stoddard. 1961. Auk, 78(4): 515-527. Repetition
of the material in the three reports just reviewed makes up much of the content of
the present one. A graph provides a handy means of reading the estimated flight
range f a small migratory bird directly from its amount of body fat as a percentage
of total live weight. Two curves are included. One represents the previous
assumption that the energy required for migratory flight is three times existence
energy. The other takes into special account the energy needed to sustain in the
air the ever-diminishing cargo of the extra fat itself. Its premise is that "flight
energy of a lean bird is two times existence energy . . ß and increases proportional
to the average weight of the bird during the trip." Whereas the corrections for fat
loading cited by Moreau (see Review 16) shorten the previously estimated flight
ranges, the new method of Odum and his colleagues produces increases of as much
as 400 miles in the case of birds with a fat weight less than half the total weight.
Comparison of Summer Tanagers (Piranga rubra) and Hooded Warblers
(SVilsonia citrina) taken in spring with individuals taken in fall indicates that the
flight estimates are of the right order of magnitude. The great variation in the
lipid content of fall Red-eyed Vireos (Vireo olivaceus) has influenced the authors to
make the following suggestion: "Since Red-eyed Vireos presumably follow both
the Florida-West Indian route and the trans-Gulf route, it may be that the fat birds
would have gone by sea and the lean birds by land!" The difficulty is how to
envision the journey via Florida and the Caribbean as a trip overland. The infre-
quency with which Red-eyed Vireos have been recorded in the West Indies seems to
permit only two alternatives: either very fexv of these vireos use Caribbean routes
or else the majority tend to fly nonstop. And the direct distance across the Carib-
bean, from the tip of Florida to South America, far exceeds the distance across the
Gulf.- R. J. Nexvman.
20. Lipase activity in the heart muscle of a migratory and a nonmigratory
bird. J. C. George and P. Thomas Iype. 1961. Auk, 78(4): 633-634. Com-
parison of the migratory Rosy Pastor (Pastor roseus) and the nonmigratory
Common Myna (Acridotheres tristis), birds similar in size, revealed 31 percent
higher lipase activity in the cardiac muscles of the latter. The result suggests that
Pastor roseus may have a lower heart rate, adapted to prolonged and sustained
flight. -- R. J. Newman.
21. Zugunruhe activity in castrated Bramblings Fringilla monti/ringilla.
B. Lofts and A. J. Marshall. 1961. Ibis, 103a(2): 189-190. Migrations by liber-
ated castrates and the arrival of some normal birds at their breeding grounds with
apparently inactive gonads have cast doubt on once general belief that gonadal
hormones strongly influence the spring flights of migrants. But these evidences are
inconclusive. Flocking inclinations might have induced castrates to travel along
with their intact fellows, and gonads can become active without perceptible
enlargement.
Lofts and Marshall have attacked the problem bv carefully removing the testes
of adult Bramblings, photo-stimulating the birds, and then testing their migratory
restlessness in activity cages. The controls exhibited Zugunruhe somewhat before
the castrates, but both groups reached similar seasonal peaks of intensity at the same
time. On a nightly hour-to-hour basis, the activity curve for the controls began
much higher, but ended much lower, than that of the castrates. The authors conclude
that the seasonal phenomena of migratory unrest and gonad development occur
,ndependently. -- R. J. Newman.
22. Some aspects on the directing and releasing influence of wind conditions
on visible bird migration. Staffan Ulfstrand. 1960. Proceedings XH Inter-
national Ornithological Congress: 730-736. Opinions about the factors releasing
bird migration and the general effects of wind on migration have been diverse.
Concentrating attention on diurnal migrants, Ulfstrand suggests that this diversity
may in large part be due to the geographic position of the observation localities and
to their surrounding topography. To demonstrate, he sets up a model situation,
contrasting impressions of the same migratory movement as seen from the south-
west corner of a land mass, a locality in the central part of the mass, and an oceanic
island offshore.
A table compares the probable relative amounts of migration likely to be observed
from the three vantage points under conditions of calm and seven different combina-
tions of wind direction and velocity. In no instance are the predicted results uniform,
and in four of the eight cases the viewpoints of all three stations disagree. The
situation is hypothetical, but it has close real counterparts in Europe. The principles
from which the imaginary station ratings are derived are unproved, but they are
widely accepted. The most debatable assumption from the American viewpoint is
that head winds have "a directly stimulating effect on the release of bird migration";
and later Ulfstrand himself concedes that "it might be that head-winds merely
contribute to the concentration of flight-lines." But such an objection is minor.
With any conceivable set of premises, migration as ordinarily observed from the
three postulated watching posts should be modified by misleading local influences
and therefore encourage geographically biased conclusions. Ulfstrand's central thesis
"that it is very difficult, even impossible to make general decisions . . . from studies
at one place only" seems well-sustained. The question remains how many currently
accepted generalizations, when critically examined, can really meet the test of having
been demonstrated at many times and at many diverse places. -- R. J. Newman.
23. The influence of wind on the migration of swallows. Claes Ramel. 1960.
Proceedings XlI International Ornithological Congress: 626-630. Data from Swedish
bird observatories in late summer and early fall show maximal numbers of swallows
flying against the wind and minimal numbers moving downwind. Indeed, from 18
August to 4 September 1947, when the wind was almost constantly northerly, 10,000
swifts and swallows were recorded at the Ottenby station actually travelling north-
ward, counter to the normal seasonal direction of migration as well as to the wind.
Ramel does not insist that migrants in general react to the wind as swallows seem
to do. He points out that sxallows feed on the wing while migrating. To do so
they have to travel at the lower atmospheric levels where airborne insects are
abundant but where higher turbulence makes gliding flight downwind both in-
efficient and dangerous. -- R. J. Newman.
24. About wintering and migration of the Common Crane (Grus grus) in
Spain. F. Bernis. 1960. Proceedings XII Ornithological Congress: 110-117.
Results of extensive inquiries (presumably by mailed questionnaire) show that the
wintering area of Grus grus in the Iberian Peninsula is much more extensive than
once supposed and that the preferred habitat there is country where stretches of
open ilex woods alternate with corn and legume fields and pastures. The migration
range is pictured as a broad band extending northeast-southwest across the middle
of the peninsula, with a central line of concentration that eventually swerves south-
ward to cross the Straits of Gibraltar to Africa on a front no more than 30 miles
wide. Some of the fringe movements point to the possibility of drift. -- R. J.
Newman.
25. Magnitude of crane migrations in eastern Washington, 1950-1951.
Charles F. Yocom and Henry A. Hansen. 1961. Murrelet, 41(3): 41. Sandhill
Cranes (Gus canadensis) on spring migration congregated at two resting areas east
of the Cascades, where as many as 1000 birds were seen in one day. Observations
indicated that some of the departing flocks passed northward along river valleys. --
R. J. Newman.
26. A spring migration of waterfowl in briefly favorable weather. J.W.
Johnson, A. B. Pack, and G. Jonkel. 1961. South Dakota Bird Notes, 13(3): 64-
70. The editor of this publication of the South Dakota Ornithologists' Union, the
United States Weather Bureau State Climatologist for South Dakota, and a biologist
have contributed to a "symposium of events" concerning an April northward move-
ment of waterfowl at Huron, South Dakota. An extensive movement of birds was
correlated with a backing shift to southerly surface winds of 10 to 30 mph, which
prevailed for more than 13 hours during the day and evening of 5 April 1960. This
wind shift was occasioned by the passage of a high pressure cell and the approach of
a warm front preceding a weak low pressure cell. It provided the tail winds usually
associated with such "pressure-pattern flying." -- Stuart L. Warter.
27. Mass migration. Dorothy Makin. 1961. Emu, 61(2): 13%141. For
a 3-hour period ending at 3 a.m. on 25 September 1960, a large flight of land birds
passed over the Pine Islet Lightstation, located about 70 miles southeast of Mackay,
Queensland, Australia. Many of these birds, flying in a light rain, were seen to be
confused by the beams from the light itself, and by light reflected from the low
cloud cover. A few birds were taken by hand during the night at the light, and
several more were located in the sparse vegetation surrounding it after daylight. --
Stuart L. Wafter.
28. Migration at Falsterbo 1957. Report 1'4o. 18 from Falsterbo Bird
Station. (Fagelstracket rid Falsterbo ar 1957.) Sven Mathiasson. 1961. Vat
Fagelvarld, 20:226-240. (English summary.) This report contains several interest-
ing items. The station was manned by at least two observers from 31 March to 30
November, the longest period in its history. The spring migration was, on the
whole, sparse. Correlated with this was the apparently slow recovery of a number
of species hard hit by disaster in 1956. A remarkable feature was the visible reverse
migration, i.e. birds flying south instead of north. In the period 31 March to 31
May, it exceeded by 3,686 individuals the number of birds seen flying north.
The fall migration appeared more "normal," although here the "disaster" species
also failed to show signs of adequate recovery. The fluctuations from year to year
of certain species are tabled and discussed. Among the birds of the Falsterbo region,
the Carrion Crow (Corvus c. corone) occupies prominence by its spectacular increase
in recent years. Although proof of nesting is still lacking, several hybrids, crosses
between Carrion and Hooded Crows (C. cornix), were observed during the fall. --
Louise de K. Lawrence.
POPULATION DYNAMICS
29. Nesting Success of Birds on a Farm in Southern Michigan. I-I. Lewis
Batts, Jr. 1961. Jack-Pine IWarbler, 39(2) :72-83. A report on the nesting success
of birds (a total of 54 species) on a 64-acre tract of land from 1948-1950. The
success of the 40 species which nested for 2 or 3 years is summarized in Table 2
according to site of nest. The results were: of 59 open nests in trees 41 percent
succeeded, of 164 nests in undergrowth 45 percent, of 109 nests on the ground 57
percent, and of 85 nests in cavities 67 percent. The success of the 332 open nests
averaged 47.7 percent. These figures agree well with the 49 percent success of
7,788 open nests of altricial birds reported in 24 studies and with the 66 percent
of 94,400 eggs in 33 studies of hole-nesting altricial birds (Nice, M. M., 1957,
Auk, 74:305-321 ).
Cowbird parasitism was light -- only 38-39 eggs in 34 nests; 14 of these (36-37
percent) fledged. The chief causes of nest loss were predation, destruction by the
elements, and desertion. House Wrens were the chief predators of the eggs in
cavity nests.
"Reproductive increase was measured in the percentage of adult breeding birds
that was represented by the fledglings which they produced (average number of
fledglings produced per breeding adult)." This was as follows: tree nesters, 81
percent, undergrowth nesters 114 percent, ground nesters 145 percent, and cavity
nesters 200 percent. -- M. M. Nice.
30. Nesting Success Calculated from Exposure. Harold Mayfield. 196l.
l/ilson Bulletin, 73(3) :255-261. Mayfield starts from the perfectly valid, but often
overlooked, point that observed losses can be related only to the period of actual
observation. Assuming that the rate of loss varies in some definable way (invariant
in the present article) the actual loss per unit of exposure can be found and from
this the total loss over the whole duration of a phenomenon, such as incubation or
fledging. The author gives so clear an illustration of his procedure that even those
who are gunshy of mathematics will be able to use it. The reviewer will only point
out that a number is more quickly raised to a power by logarithms than by repeated
multiplication by itself. If the lesson of the article is learned the credibility of
nesting success figures will be greatly enhanced. -- C. H. Blake.
31. Preliminary Method for Estimating Stability in Plankton. B. C. Patten.
1961. Science, 134(3484):1010-1011. Although applied to plankton, the method
given here might be applied to comparing the variability of a population of birds
over a period of years to the variability of a set of environmental factors such as
mean temperature, rainfall, food items, predator populations, etc. taken all together.
The measure used is an empirical one which implies a linear effect of each variable
upon the population. The article has one major defect: the calculation of "transition
probabilities" is not explained and the reviewer cannot work it out with certainty
from the example in Table 1. -- C. H. Blake.
BEHAVIOR
32. On distraction displays and so called "play" behavior in birds. (Avle&
ningsbeteenden och s. k. lekyttringar hos faglat.) Martin Markgren. 1961. Vat
Fagelvarld, 20:214-224. (English summary.) All too often students of animal
behavior fall into the habit of using accepted ternas without making clear to them-
selves through careful analysis whether these expressions actually fit the behavior
they wish to describe. In this paper the author discusses two kinds of behavior,
distraction displays and "play" rituals. He disassociates himself from such terms
as "injury feigning," "dance," and 'play," suggesting that they are unrealistic. To
illustrate his point he makes a clever analysis of the distraction display of a Dotterel
(Charadrius morinellus), showing that its display is a "dynamically balanced" be-
havior pattern including aggressive, escape, and brooding drives, which alternate
with the constantly changing situation.
As to the terms "play" and "dance," he suggests that they be eliminated from
ethological parlance. They were brought into use primarily based on the anthropo-
morphic conceptions of casual observers who saw sexual and other displays of
birds without realizing their intrinsic meaning and underlying tendencies. The
author denies the probability of birds being within the level of organization that
permits play as an acting performance and dance as rhythmic movement executed
for the mere pleasure of motion. From my own experience with woodpeckers, I
fully agree. The shortcoming, however, rests not with the birds but with the observer
who lacks the penetration to see them as they really are, living and reacting in full
accordance with their station within the organization of life.
My one criticism of this stimulating paper is that it is too short and incomplete.
It is to be hoped that this talented observer will eventually publish a more extensive
dissertation on a subject he apparently understands exceptionally well. -- Louise
de K. Lawrence.
33. On the Evolutionary History and Taxonomic Value of Some Motor
Patterns of Birds. (Ueber die Stammesgeschichte und den taxonomischen Wert
einiger Verhaltensweisen der Vi3gel.) Wolfgang Wickler. 1961. Zeitschrift fiir
Tierpsychologie, 18(3): 320-342. (With English summary.) Several pairs of
motor patterns, each pair of which perform the same function, "are investigated
with a view to their relative phylogenetic age." Tables are given showing which
orders, families, genera and sometimes species walk or hop, which scratch over or
under the wing, which do or do not retrieve eggs from out of their nests, and which
(among the Sturnidae and Icteridae) do or do not use their bills for prying. In
the light of the large amount of information gathered, the author points out the
impossibility of deciding which is the ancestral pattern in these and several other
behavior patterns. The manner in which doves and sandgrouse drink by sucking up
the water has been considered an important indication of relationships, yet the author
notes that one dove (Didunculus) -- a primitive form -- drinks like a goose and
that certain Astrildine finches drink by sucking up the water. -- M. M. Nice.
34. Attacking Beha,vior in Homosexual Groups of the Bengalee, Uroloncha
sriata, vat. domesfica Flower. Hiroyuki Masatomi. 1959. Journal of the
Faculty of Science, Hokkaido University, Series VI, Zoology, 14(2):234-251. Al-
though the Bengalee is "famous for its mild temperament," the author found
considerable hostility between the members of two homosexual groups of five birds
each. Two homosexual pairs were formed within each group and aggression appeared
primarily between these pairs in relationship to the one nest provided in each cage.
The observations are summarized in three sets of sociograms. The author discusses
many other studies in relation to social hierarchy, territory, homosexual relationship
and frustration. -- M. M. Nice.
35. Territorial Behaviour Between Two Pairs of the Bengalee in Two Differ-
ent Cages. Hiroyuki Masatomi. 1960. Journal of the Faculty of Science, Hoh-
kaido University, Series VI, Zoology, 14(3): 387-409. The two pairs of the
Bengalees were put first into a large elongate horizontal cage, then after a month
transferred to a large vertical cage. Territories were established around each nest
provided; eggs were laid and incubated, but they failed to hatch, due in part to
interference between the pairs. Territorial behavior did not differ in the two types
of cages. These birds had already raised young in other cages. The author suggests
that "Pre-existence of the pair bond before the beginning of observation may be one
of the most important factors in the formation of a definite territoriality." A wide
selection of references is discussed. -- M. M. Nice.
36. Communal Use of One and the Same Nest by Two Breeding Pairs of
the Bengalee. Hiroyuki Masatomi. 1961. Behaviour, 17(4): 261-2"/4. Four
sibling Bengalees were kept together continuously in a cage 100 cm. high, 70 cm.
wide and 100 cm. long. The cage contained one artificial dome nest of straw. The
birds paired and all four used the one nest without friction. All incubated, but
the embryos died in the shell. A new-born white mouse was substituted for the
eggs; one female brooded it, then regurgitated food, stood up and twice touched one
of the mouse's forelegs with her bill, the mouse responding by twisting around.
A male Bengalee attacked the strange object, whereupon it was removed and a
day-old Bengalee put in its stead. It proved a trial and error process for one female
to place food into the gaping mouth of the nestling, but the other three adults
apparently fed with almost no trouble. The young bird was cared for by all members
of the group.
The author remarks, "As a rule, the smaller the cage or the denser the population,
the less aggressive may be the Bengalee." He concludes, "The availability of only
one ready-made nest in the cage was considered one of the most important causes
of the curious outcome, in combination with the gentle temperament of the species
in general." -- M. M. Nice.
37. On the Use of Tools by the Woodpecker Finch. (Ueber den Werkzeugge,
brauch des Spechtfinken Camarhynchus pallidus (Sclater und Salvin). Irene/us Eibl-
Eibesfeldt. 1961. Zeitshrift /iir Tierpsychologie, 18(3):343-346. Observations
and lhotographs of this Galapagos finch, one of the few birds known to use a tool.
It knocks at branches, then leans its ear close to the surface. If it cannot get the
prey with its beak it probes with a cactus spine or small twig. Thus it drives out
or impales the insect. Ill fitting tools are worked over and adapted. -- M. M. Nice.
38. The Congo Peacock (Afropavo congenis (Chapin)). F. J. Appelman.
1961. Avicultural Magazine, 67(2): 41-42. In 1959 a pair of these rare birds was
placed in the Rotterdam Zoo in an aviary planted to resemble a tropical forest and
kept at high temperature and humidity. In 1960 they bred. The hen laid three
eggs in a basket in a willow-tree and incubated them for a month. Soon after hatch-
ing one chick let itself fall down and "The cock at once ran to the chick . . . and
behaved completely like a hen, warming the chick under his breast and wings and
showing the little creature how to look for food." The chicks took food from their
parents' bills. They were very vigorous and could fly a little in 2 or 3 days. Three
photographs of the family are shown; one of these is in color. -- M. M. Nice.
39. Some Recent Records of Anting in Passerine Birds. K. E. L. Simmons.
1961. Avicultural Magazine, 67(4):124-132. A list is given of 96 passefine species
seen anting by the author; 49 of these records are of previously unrecorded species.
The ants used are specified. The majority of the birds were seen anting in the
London Zoo. A list of passefine families is supplied, with the number of species
in each that have been recorded as anting; these vary from zero to 23, Turdidae,
Sturidae and Timaliidae having the largest numbers. Mr. Simmons concludes this
valuable summary with a plea for further "records of true anting (with ants) by
passetines," with a description of the kind of full and careful information needed.
-- M. M. Nice.
40. The Smallest Parrots of the World. Sten Bergman. 1960. Avicultural
Magazine, 68(6):209-215. In Dutch New Guinea the Woodpecker Parrot (Microp-
sitta keiensis chloroxantha) excavates a nesting hole in a tree termite nest. The
author found three nests, in each of which both parents and two to four older young
spent the night with the eggs or new chicks. One father was seen to feed two of
these older young. Despite earnest efforts Dr. Bergman was not able to find food
acceptable to the birds. Although they ate a few termites, it is believed their chief
food must be some lcind of a fungus. Several photographs are given of these tin)'
parrots, 3/2 inches in length.- M. M. Nice.
41. Observations on Breeding Behavior of Veeries in Michigan. Ormsby
Annan. 1961. Jack-Pine Ig/arbler, 39(2):62-71. Studies on seven nests of
Hylocichla fuscescens at Douglas Lake, Michigan in 1956 and 1957. Five of the
nests each contained 2 Veery eggs and 2 Cowbird (Molothrus ater) eggs; 2 con-
tained 4 Veery eggs apiece. One of the former was deserted after its discovery:
from the 6 others 10 Veeries and 6 Cowbirds fledged. The female at one nest
incubated 77 percent of the daylight hours while watched: the average period on
the nest lasted 53 minutes. The males sang much and called their mates off the
nest when approaching with food for the young. During the 9th day of nest life
at one nest a 30-inch garter snake seized the larger Cowbird but was unable to get
it loose. The parents attacked the snake with feet and wings and drove it off on 9
different occasions during 2 hours. -- M. M. Nice.
ZOOGEOGRAPHY
42. The avifauna of Lina bog 1947-1960. Lina myrs fagdiN aren 1947-
1960.) Karin Jansson. 1961. Vat Fagelvarld, 20:193-211. (English summary.)
This is a careful study of the bird-life at one of Sweden's most famous bird habitats
located in the eastern part of the Baltic island of Gotland. During the study, the
author, a school-teacher of the nearby village school, spent days and nights faithfully
recording what she heard and saw to produce this swansong of a doomed area full
of irretrievable nature treasures on the verge of its disappearance. Thus, despite its
form of annotated list covering some 133 species and its terse English summary, this
paper acquires a special interest and poignancy that cannot escape the conservationist
reader. What man does to acquire more land for his plow and his beasts or to
preserve the land he already possesses from floods or drought does not always turn
out exactly as planned. So he digs deeper into the earth and drains more from
nature's reservoirs to influence, most often unpredictably and disastrously, the lives
of every plant and animal organism that through the ages throve in these particular
blessed environs. Here, through the white nights of May and June, the Corn Crakes
(Crex crex), 40 to 50 of them, are heard croaking their grinding notes all over the
Lina bog, perhaps the only place on earth where this rail is still to be found in
abundance, but soon to vanish together with Lapwings (Vanellus vanellus), Ruff's
(Philomachus pugnax), and all the others that gave to the bog its entrancing charac-
ter. The author's descriptions, precise and graphic as they often are, vividly
accentuate the subtle interplay of the being and not being of all those supporte/:l
by the bog now and in the past.
Many of us carry out similar investigations into the life belonging to one particu-
lar spot on the map and through the passing years acquire some comprehension of
the ever changing trends of events. But often this is as far as we go, and our
discoveries of nature's secreted history, like that of the Lina bog, remain buried in
the dust of forgotten records. -- Louise de K. Lawrence.
SYSTEMATICS
43. Distance as a Measure of Taxonornic Similarity. R. R. Sokal. 1961.
System. Zool., 10(2):70-79. The author comments briefly on the recent history of
"numerical taxonomy." The computation of taxonomic distance at present requires.
inter alia, that only observed values (actual measurements or ranks) are used and
all characters are given equal weight. The concept of taxonomic distance goes back
more than 60 years and has had its most elaborate formulation by Rao in 1952. In
essence, the problem is to reduce the set of n measured differences between the
objects, which can only be presented initially in ,-dimensional space, to three, or
better two, differences which can be presented in real (Euclidean) space so that the
distance may be directly measured. Obviously we avoid the geometrical difficulties
of n-dimensional space by a resort to computation. The actual solution of the matrix
is given by Sokal in an appendix.
The relation to Pearson's coefficient of racial likeness and Mahalanobis' generalized
group distance is discussed. Sokal notes that these two procedures take account of
the variances of the characters used.
The reviewer ventures some comments. (1) It appears gratuitous to state that
discontinuously varying characters should be handled only by ranking rather than
by their actual measurements when the latter can be obtained. (2) The method as
here stated leaves it moot whether more than two taxa can be considered in such a
way that all the distances between them are to the same scale. Mahalanobis' method
allows this. Without attempting a calculation the reviewer is of opinion that
Sokal's method also permits this provided all the taxa afford the same characters
and each is measured or ranked on its own uniform scale. The definition of scale
is left open. (3) An implied assumption by the author is that any individual may
be recognized as a member of a particular taxon. (4) The reviewer would have
welcomed a comparison with the discriminant function.
The methods of "numerical taxonomy" need experimental application to organ-
isms offering a diversity of taxonomic problems. These methods should prove of
real help without necessarily displacing traditional procedures. They will probably
never be a substitute for sound taxonomic judgment. -- C. H. Blake.
FOOD
44. Conservation and Psedation Problems of Birds of Prey in Sweden. Kai
Curry-Lindahl. 1961. British Birds, 54(8):297-306. Contrary to general opinion,
birds of prey need little food. In a large cage in a zoo the average food consump-
tion per day per bird for five Buzzards (Buteo buteo), two Goshawks (Accipiter
gentills) and one Rough-legged Buzzard (Buteo lagopus) was 170 gin., about 6
ounces. Of two Goshawk pairs nesting a mile apart one specialized on Woodpigeons
(Columba palumbus) and Black-headed Gulls (Larus ridibundus) and the other
on Jays (Garrulus glandarius). Descriptions are given of birds of prey capturing
injured and/or abnormally behaving victims. Most birds of prey in Sweden are
territorial, but Ospreys (Pandion haliatus) sometimes nest in colonies; several pairs
may fish without friction in a restricted portion of a lake. A very interesting paper.
-- M. M. Nice.
45. The Food of Birds of Prey and Owls in Fenno-Scandia. G/3ran Bergman.
1961. British Birds, 54(8) :307-320. This is a summary of the published informa-
tion on the food of 17 diurnal birds of prey and 10 owls in Finland and Scandinavia.
-- M. M. Nice.
46. The Relationship Between Foot-movements and Feeding in Shore Birds.
John H. Sparks. 1961. British Birds, 54(9): 337-340. The author points out that
foot-paddling movements on intertidal mud flats do not result in the emergence of
marine worms, but rather of small amphipods and sand shrimps. He believes that
foot-paddling of gulls on wet grassland is a carry-over from this behavior that is
functional in the intertidal zone, "but the capture of earthworms near the surface
and trampling movements are in no way related as cause and effect." -- M. M. Nice.
BOOKS AND MONOGRAPHS
47. Locomotor Mechanisms of Birds. Frank A. LIarrman. 1961. Smiths.
Misc. Coll. 143(1):1-91. (See also review No. 33, in this issue). This is a re-
markable compilation of original measurements of "more than 360 species in "0
families" of New World birds. The real meat is contained ia five tables which are
much more significant than the general discussion. Table ! gives body weight (gin.),
heart (%), main muscles of wing and shoulder (%), main leg muscles (%),
wings (cm'/gin.); aspect ratio, pectoral and supracoracoid muscles (%), pectoral
muscles (%), supracoracoid (%), "rest" of muscles of wing and shoulder (%),
tail (cm,/gin.), "glide" or total projected area of wings, body, and tail (cm'"/gm.),
buoyancy index. These are for almost all species, with male and female recorded
separately. The deviation measure given is the standard error of the mean. To
convert to the more meaningful standard deviation multiply by the square root of
the number of variates.
My particular interest in the aerodynamics of bird flight leads me to offer both
general and specific criticisms of the table. The only real reason for finding such
quantities as wing loading or aspect ratio is to use them ultimately in the calcula-
tion of aerodynamic characteristics such as the coefficients of lift and drag and finally
power requirements. If it be admitted that the measured quantities are not ends
in themselves, then they must be so stated that they will fit into the equations yield-
ing the aerodynamic quantities. These equations, in the American and English
aeronautical literature, are in English units. The calculations are not a whir more
difficult than with metric units.
The item "wings" should be wing loading in ibs/ft". To convert to the latter
take 2.05 times the reciprocal. The author calculates his aspect ratio by dividing
the length of an extended wing by the "median chord." He tells me this latter
was actually an estimate of the mean chord. The result obtained is shown by my
own calculations for 39 of the species to be somewhat less than half the true aspect
ratio. The correct mode of calculation is span/area of both wings. The span is
twice the length of an extended wing measured from the edge of the body. The real
mean chord is span/aspect ratio and is used to calculate a value of the Reynolds
number.
The expression of the tail area as the reciprocal of a loading is rather misleading
since it innplies that the tail contributes to lift. The shape of the tail in longitudinal
section shows that this almost certainly is not so. The tail does contribute to drag.
but this involves only the area and the skin friction. In established flight the chief
function of the tail is to control pitching movements. It does of course, have other
functions during maneuvers. Dr. Hartman tells me the area of the spread tail was
measured much as in the well-known book by Baldwin et al. In normal flight most,
if not all, birds carry the tail rather tightly closed.
The author tells me he intended the term "glide" as a measure of the resistance
to vertical fall of a bird with outspread wings and tail. The area as such would
be the best figure from which to compute the resistance -- which is a drag. I find
a usable expression for low speeds given as: 1.28 x area x f2 density of air x velocity
squared (all in the English system, see Dommasch et al. 1958, Airplane Aero-
dynamics, p. 177). This kind of vertical fall could last but briefly in the open air.
Even very slight turbulence would throw the bird into a spin or side slip with a
resulting change in drag. So far as is now known only the wings contribute to lift.
By calculating back to the area used in "glide" and doubling, one may estimate the
total wetted area approximately. This is a necessary quantity in the calculation of
parasitic drag.
I am not yet able to see the revelance of the buoyancy index to flight. Buoyancy is
rather a misnomer since the specific gravity of a bird is about four orders of magni-
tude greater than that of the air.
The remaining tables show, for selected species, seasonal variation in proportional
heart weight, muscles of wings and of legs in more detail, and a comparison of the
mean data of Table 1.
These criticisms really illustrate the need for time and patience in establishing
communication between the biologist and the engineer. Each must learn something
of the language and philosophy of the other. I suggest that ornithologists put on
record the actual weights, areas, and lengths, letting the user calculate such ratios
as he wants.
In spite of all that has been said above, Dr. Hartman's paper contains an immense
amount of useful information. -- C. H. Blake.
48. Der Flug der Tiere. Herta Schmidt, ed. 1960. W. Kramer, Frankfurt
a/M., 164 pp., illus. $3.00. In 1959 the Senckenberg~Museum produced for the
50th anniversary of the International Aeronautical Organization an exhibition deal-
ing with natural flight. The staff wrote an explanatory pamphlet of which the
present volume by the editor and seven other authors is a revision and enlargement.
The section on birds, pages 77 to 112, is by Joachim Steinbacher. The treatment
may be called traditional. It is frankly addressed to the laity and is non-mathematical.
Perhaps this is all we can ask for in a small book which summarizes the whole
subject of animal flight. The author seems overcredulous in the matter of speed.
His diagram must refer almost entirely to extreme speeds and in some cases is
almost certainly over the mark.
The reviewer will not attempt a critique of the other sections of the book. In the
section on aquatic flying animals attention should be called to the discussion of the
flying characinid fishes of tropical America. These fishes may be capable of true
powered flight. The reviewer, from personal observation, is still convinced that the
more famous exocoetids are solely gliders. -- C. H. Blake.
49. The Birds of Trinidad and Tobago. G. A. C. Herklots. 1961. Collins.
London. 287 pp., 16 colored and 4 black and white plates, 13 line drawings. $10.00.
The two islands of Trinidad and Tobago with an avifauna of about 400 species
provide a comfortable introduction to the vast riches of continental tropical America.
The present book is a field guide patterned after Bond's guide to the West Indian
rather than after Peterson. Under each species there are paragraphs for: descrip-
tion, nidification. habitat, range, and field identification. Some of these paragraphs
are omitted for vagrant or doubtful species, and voice is added where it is signifi-
cant. Subspecies are treated more briefly, usually only a statement of difference from
the main form and of range.
In general the scientific names agree with those used by the Phelpses for Venezuela
and with the A.O.U. Checklist. The most peculiar departure is the use of Ceophloeur,
with Dryocopus as a synonym, and the use of the latter in place of Coccyzus. The
English vernacular names of the more conspicuous species include those in actual
local use as well as the familiar book names. For many species French names are
also given. The common vernacular of Trinidad was French until quite recent times.
The color plates are the work of the author. With a few exceptions, mostly
hummingbirds, only the head and shoulders are shown. The reviewer can say from
personal experience in the islands that this restriction is no great disadvantage to
the user of the book. Herklots is not a highly skilled ornithological artist, but the
essential facts are adequately displayed. The four black and white plates and most
of the line drawings are by Jackson Miles Abbott. His craftsmanship is very good.
This book will be indispensable to the bird-watching visitor to the islands and
should serve as an introduction to the birds of all northeastern South America. We
may also hope that it will stimulate local interest in birds. -- C. H. Blake.
50. Birds of the World. Oliver L. Austin, Jr. 196l. Golden Press, New York.
316 pp., 300 colored illustrations by Arthur Singer. Size 10,/2 x 132". Price $14.95.
In ten years of reviewing ornithological publications, I have never approached my
typewriter with such mixed feelings as I do in reviewing Dr. Austin's long-awaited
book. My reactions can be compared to that of a lover of good apples, who picks up
a beautifully polished, perfectly shaped apple, of a variety reputed to be especially
flavorsome. After duly admiring the external appearance, our apple-lover takes his
first bite. It is almost as delicious as expected, but within the apple, unfortunately,
the eater encounters several rather messy worm tunnels. These in no way detract
from the beauty of the apple, and the flavor of the flesh around the worm-holes is
still delicious, but somehow the apple-lover can never feel quite the same about that
particular piece of fruit. It is a large apple, and the worm tunnels small, but still
their overall effect on the apple-eater outweighs their actual damage to the fruit.
The book, of course, is not primarily intended for the ornithologist. The lay
reader cannot help but exclaim at the beauty of "Birds of the World," for it is
a magnificent piece of book-making with respect to layout, typography, paper, bind-
ing, color-printing, etc. The only worm-holes the non-ornithologist is likely to
notice are the typographical errors in ordinary English words. These are but a
symptom of the general sickness; for all its beauty, this is the most error-ridden
bird book to have come to my attention in years. This is all the more unfortunate
in view of its genuine merits, and high price. The errors are of several kinds, and
the blame for them must be laid at several doorsteps. Most inexcusable are the
myriads of typographical errors and misspelled words, both in English words and
scientific names. It is impossible to tell whether some of the misspellings may have
appeared in the original manuscript; in any case, these should have been caught
before publication. Errors in the captions of illustrations are of several types. In
an unfortunate number of instances, the species illustrated is not correctly identified
in the caption. In a few cases, correct captions have been transposed between
illustrations. Among the correctly identified birds, there are caption errors in size
and distribution statements, these sometimes conflicting with statements in the text.
Blame for the errors listed above lies in part with the author and artist, for not
having double-checked all identifications. The greatest burden of the blame, in my
opinion, belongs to the publisher. This was a major publication project, with a
tremendous production budget and a virtually unprecedented advertising campaign.
The reviewer cannot know whether it was the desire to save a few dollars, (which
seems ridiculous) or the haste to get the book into the stores well before Christmas
(which seems probable) that caused the publishers to slight the proof-reading and
other aspects of quality-control.
It is my understanding that this book appeared without having been thoroughly
and critically read in advance of publication by a paid scientific reader. Whether
attributable to economy or haste, this was as bad a lapse on the part of the publisher
as the inadequate proof-reading. The publisher's proof-reader would understandablv
have missed the incorrectly spelled scientific names and technical terms. The scientifi
reader would be expected to catch these, as well as errors of fact in the text itself.
Both Dr. Austin and this reviewer are well aware that nobody can know everything
about birds; in the process of such a tremendous compilation of facts as "Birds of
the World," any one author, if human, will err. But a thorough reading by another
ornithologist might have caught such errors as the attributing to night-jars of
"large yellow eyes" (p. 162) or the identification of the introduced British Columbia
population as the Common Myna (ztcridotheres tristis) rather than the Crested
Myna (/. cristatus).
Enough discussion of the worm-holes. Those purchasers of the book who are
interested in doing so may obtain from Dr. Austin a mimeographed list of errata,
and the book will almost certainly sell well enough to warrant additional printings,
permitting at least some of the errors to be corrected when this can be done without
radical resetting of type. What of the text itself?
It is inevitable that Dr. Austin's book will be compared with E. T. Gilliard's
"Living Birds of the World," which has, after all, the same basic cast of characters.
It is quickly apparent that Austin writes more naturally and easily than does Gilllard,
with a style better suited to the lay reader. Gilllard frequently identified by name
the authorities responsible for various ornithological discoveries; Austin seldom does
this. Gilllard made much more of an effort to assemble the most complete and
up-to-date material available on all groups of birds; Attstin's shortcomings on this
score are a function, in large part, of the difference between library facilities available
at the American Museum of Natural History and at the University of Florida. By
using commissioned paintings for his illustrations, Austin was able to pick and
choose his examples for each family (and illustrate every family and most major
subfamilies), and adapt the grouping of birds to the page layout. Gilliard's use
of photographs robbed him of these advantages, but brought a sense of authenticity
often lacking in the painted illustration. Gilllard identified the species being dis-
cussed in tb, e text by the use of scientific names. These were largely eschewed by
Austin, and this I believe to have been a mistake. There is little or no problem in
identifying North American or European birds by their English names, but there are
few really standardized English names for the birds of most of the rest of the world.
The species called Gray Drongo by Austin is called Ashy Drongo by Vaurie,
monographer of the family. Picathartes is called Bald Crow in Austin's picture
caption, Bareheaded Rock Fowl in his text. Tangara nigro-cincta is called Golden-
masked Tanager by Austin, following Skutch; Hellmayr calls this the Black-banded
Tanager. Eisenmann's authoritative list of Middle American birds uses Golden-
masked Tanager only if the Central American population is considered a separate
species, T. larvata: if conspecific xvith the South American nigro-cincta, Eisenmann
advocates calling the species Masked Tanager, as is done on the caption to Austin's
illustration !
Another strong argument in favor of the use of scientific names in the text lies
in the future appearance of foreign language editions of Austin's book. In the
absence of scientific names. translators are inevitably going to misidentify and mis-
translate unfamiliar English bird names.
As mentioned earlier, Austin's style is eminently readable. The content of his
text is somewhat uneven. Dr. Austin has had the advantage of field experience
with birds in several parts of the world, and it is most refreshing to come across
first-hand material in a compiled work such as this. His personal enthusiasms may
occasionally run awav with him, however; the amount of space devoted to the
Common and Arctic Terns, while packed with significant information, is perhaps
not commensurate with their status as 2/8,635 (using Austin's figures) of the species
of birds of the world. Gilllard proved to have the same perfectly human bias in
devoting eight pages of his book to birds of paradise and bower birds versus four
pages for the Fringillidae. Austin's selection of examples for discussion in some
widely-distributed families is adnnirably broad; in others (cf. Tyrannidae, Icteridae)
there is a heavy emphasis on North American species, sometimes to the detriment
of a real appreciation of the range of variation within these large families.
The classification used by Austin is basically that of Wetmore, modified to some
extent to accord with recent revisions and Austin's own opinions. Here, too, the
treatment is somewhat uneven. Austin has been perhaps over-quick to adopt in toto
some recent rather radical revisions (cf. certain parts of Bock's revision of herons),
but has missed others noxv more-or-less generally accepted (cf. Deignan's allocation
of atpalopteron to the Meliphagidae rather than to the Timaiiidae).
The illustrations by Arthur Singer form such an important segment of this book
that they deserve virtually a full-scale review of their own. Mr. Singer was little-
known to most ornithologists prior to the appearance of this book; his name will be
a household word from now on. The illustrations were painted over a period of
several years. Without dates it is impossible to know the sequence in which the
paintings were done, but it is quite reasonable to suppose that the contrast between
the atrocious waterfowl on pages 68-69 and many of the lively and lifelike oscines
represents a maturing of Mr. Singer's abilities as a bird artist. He is not always
successful in translating the stiffness of a study skin into a convincing posture when
painting birds of groups wholly unfamiliar to him in life (cf. the bee-eaters), but
in other cases he has done remarkably well. His sense of design, his adaptation of
poses to the demands of a page layout, are superb. He has made a few out-and-out
errors. In some cases these are soft-part colors, whose difficulty of obtaining is the
bane of conscientious bird artists everywhere. The cere of the Cape Barren Goose,
for instance, is apple green rather than dull yellow as Singer has painted it, and' the
iris of the Barred Antshrike white or pale straw rather than deep yellow. There
are occasional errors of structure or proportion; the Plush-capped "Tanager"
(Catamblyrhynchus) must have been painted from a specimen with rectrices only
partially emerged during molt. Singer unaccountably omitted one leg of the
Gentoo Penguin on p. 28. Most of the paintings, however, even those that are not
quite convincing to the eye of the ornithologist, are accurate in detail and attractive
in design, and serve their purpose perfectly adequately.
To summarize, Dr. Austin's book is a highly admirable attempt at the almost
impossible. Its general excellence is marred by a series of unfortunate errors, some
understandable, some utterly inexcusable. I am especially sorry that it does haYe
shortcomings that could have been avoided, because it will probably be a long time
before anybody else attempts a book of this scope. Anybody who does try to surpass
it (and the burgeoning of competing bird books suggests that other publishers will
be wanting a world ornithology on their Christmas book lists in the future) will
have a real job on his hands. -- Kenneth C. Parkes.