SUMMARY
The 37 species in the subfamily Charadriinae are compared and possible functions of the head and breast patterns are reviewed. It appears that these patterns disrupt the body and eye outlines, which is especially important for the nesting bird. In some species the patterns may enhance sex recognition and may serve as reinforcers for aggressive displays. It is proposed that the primitive Charadrius stock had breast bands and nested
on shingle and that as this genus radiated the markings took on social signal functions and were modified by new selective pressures in new habitats. It appears doubtful that the black lore lines have any value as feeding sight lines among the Charadriinae species.
OTT (1966) proposed that many of the markings of shorebirds function
as disruptive coloration. Tinbergen (1953) and many other authors
suggest that many avian plumage patterns have signal function and reinforce
display movements. Ficken and Wilmot (1968) and Ficken, Matthiae, and
Horwich (1971) suggested that eye lines in many vertebrates may enhance
their vision and enable predaceous species to locate and capture prey more
effectively. The latter authors further suggest that the head markings of the
Semipalmated Plover (Cha.radrius semipalmatus) probably serve mainly a
disruptive coloration function, although they point out that a given pattern
may serve several functions. Bock (1958) tentatively speculated that in
Charadriinae the breast bands and head markings act as disruptive marks,
especially for the nesting bird, and some of the markings also reinforce
aggressive and courtship displays.
I have examined the literature concerning the Charadriinae in search of
correlations that might provide suggestions on the relative importance of
these possible functions in the subfamily as a whole, since many members
of this group have complicated head and breast patterns and many have
black lore lines. I have given special attention to (1) nest-site characteristics
and (2) seasonal, sex, and age differences in coloration. I have also relied
upon my 1969-72 observations on the Mountain Plover (C. montanus) in
eastern Colorado for part of my conclusions.
Jehl (1968) lists 37 species in the subfamily Charadriinae in his system
of shorebird taxonomy and I have followed his scheme.
RESULTS AND DISCUSSION
A variety of head and breast markings is found in Charadriinae with 24
basic patterns (Fig. 1) representing the 37 species in this subfamily. All
species except the Hooded Dotterel (C. rubricollis) have an interrupted, i.e.
non-uniform, head pattern (Table 1). Within the genus Charadrius there
is a high incidence of a black lore line and a black crown patch and within
the entire subfamily 21 species have distinct breast bands (Table 1). Breast
bands when present usually consist of dark bands on light backgrounds, but
in two cases light bands are against a dark background (Fig. 1).
Cott (op. cit.) states that the round shape of the eye is a conspicuous
feature that needs to be concealed in many species and that eye lines com-
monly serve this function. Of the 37 species considered here, 27 have the
60
Walter
D. Graul
CHARADRIINAE HEAD AND BREAST MARKINGS
61
Fig. 1. Breeding adult head and breast patterns in Charadriinae. (A) Charadrlus
hiaticula; similar patterns = C. collaris, C. dubius, C. placidus, C. semipalmatus, C.
thoracicus, C. wilsonia. (B) C. voci[erus; similar patterns = C. trico#aris. (C) C.
melodus. (D) C. pecuarius; similar pattern = C. sanctaehelenae. tE) C. alexandrinus;
similar pattern = C. marginatus, C. peronli. (F) C. venustus. (G) C. bicnctus. (H)
C. [alklandicus. (I) C. leschenaultii; similar pattern = C. mongolus. {J) C. asiaticus;
similar pattern = C. veredus. (K) C. modestus. (L) C. montanus. (M) C. melanops.
(N) C. cinctus. (0) C. rubricollis. (P) C. novaeseelandiae. (Q) Anarhynchus [ron-
talis. (R) Phegornis mitchelli. (S) Pluvialis dominica; similar pattern = P. apricaria.
(T) P. squatarola. (U) P. obscura. (V) Eudromias morinellus. (W) Oreopholus
ru#collis. (X) Pluvianellus socialis.
eye outline interrupted by a black line and six additional species have the
dark eye against a uniform dark background (Table 1). Either of these two
strategies would tend to conceal the eye. The fact that several of these species
have colored eye rings does not detract from this function, since the colors
cannot be seen at a distance.
In at least 24 of the species the head and breast colors are either absent
or subdued in the non-breeding season as compared to the breeding plumage
(Appendix I). In addition, immatures in at least 35 species differ from their
respective adult breeding plumages (Appendix I). These data support the
hypothesis that the patterns are mainly functional for adults during the nesting
season.
March 1973
62 THE WILSON BULLETIN Vo. as, No.
TABLE 1
SUMMARY OF BREEDING ADULT HEAD AND BREAST MARKINGS IN CHARADRIINAE
Other
Charadrius Charadriinae Totals
Number Species in Group 28
Lore-line Present 19
Black Crown Patch Present 21
Uniform Dark Face 3
Breast Band Present 18
Eye Outline Interrupted by Black Line 24
Interrupted Head Pattern 27
9 37
2 21
0 21
3 6
3 21
3 27
9 36
Support for the theory that these patterns function as disruptive coloration
during nesting comes from the correlation between the presence of breast
bands and characteristics of the nest site. Table 2 shows that those species
that nest on a discontinuous substrate (Appendix II) tend to have breast
bands while those that nest on uniform substrates (Appendix II) tend to
lack breast bands. Discontinuous substrates are defined as having many con-
trasts between light and dark colors (shingle, disturbed areas, stony areas)
whereas uniform substrates have no great contrast between light and dark
colors (sand expanses, uniform grasslands, holes). A Chi-square Test of
Independence shows that the difference is significant (P < 0.025). Two
species were omitted from Table 2 because of a lack of good nest-site infor-
mation and six species were omitted because they cannot be placed into one
of the two substrate classifications, since they commonly nest near conspicuous
dark objects (pebbles, sea drift, shrubs) on an otherwise uniform substrate
such as fine sand (Appendix II). This correlation tends to support Huxley's
(1958) suggestion that the breast bands in the Killdeer (C. voci/erus) have
a disruptive function.
Indirect evidence supports the hypothesis that some of the head and breast
TABLE 2
PRESENCE OF BREAST HANDS VS. NEST SITE LOCATION*
Discontinuous Uniform
Nest Substrate Nest Substrate Subtotals
Breast Band Present 13 4 17
Breast Band Absent 4 8 12
Subtotals 17 12 29
* Compiled from data in Appendix II.
Waiter CHARADRIINAE HEAD AND BREAST MARKINGS 63
D. Graul
FIG. 2. Horizontal threat display given by the Mountain Plover.
markings in this group also have social signal functions. For instance, in
those cases where both sexes incubate (the normal situation in this group)
identical head and breast markings would be expected if their sole function
is disruptive coloration. In at least 27 cases where both sexes are reported
to incubate, however, the male has brighter head and/or breast markings
than the female (Appendix I). In the Dotterel (Eudromias morinellus) the
male usually incubates alone (Pulliainen, 1970) and the female has brighter
markings. Since sexual differences do exist it is likely that the differences
enhance sexual recognition.
In at least the Killdeer and the Banded Dotterel (Charadrius bicinctus)
the breast bands appear to reinforce aggressive displays, since in both species
the bands are enlarged in threat postures (R. E. Phillips, pers. comm.).
In the Mountain Plover the facial markings seem to serve as reinforcers
for threat displays. Males are more aggressive than females and males have
brighter facial and breast markings. The most common threat display in
this species (the Horizontal Threat--Fig. 2) presents a bold black and white
image to the threatened bird. Another aggressive posture in this species
(the Upright Threat), whereby two opponents stand close together and face
each other with the bodies nearly vertical, also presents the bold facial mark-
ings to both participants. Both of these displays, or similar versions, have
been described for the following additional species: the Kentish Plover (C.
alexandrinus) (Rittinghaus, 1961), the Little Ringed Plover (C. dubius)
(Simmons, 1953a), the Ringed Plover (C. hiaticula) (Simmons, 1953b), the
Killdeer (Bunni, 1959), and the European Golden Plover (Pluvialis apricaria)
(Bannerman, 1961). At least the Horizontal Threat, or a similar version,
occurs in the Double-banded Plover (C. bicinctus) (R. E. Phillips, pers.
comm.), the Black-fronted Dotterel (C. melanops) (R. E. Phillips, pers.
comm.), the American Golden Plover (P. dominica) (Drury, 1961), the New
64 THE WILSON BULLETIN March 1973
Vol. 85, No. 1
Zealand Dotterel (P. obscura) (R. E. Phillips, pers. comm.), and the Black-
bellied Plover (P. squatarola) (Drury, op cit.). I suspect that future research
will demonstrate that most of the Charadriinae species have aggressive dis-
plays in which a frontal view is presented to the opponent. It is perhaps
significant that the black crown patch in 21 of the species of Charadrius is
restricted to the front edge of the crown--the maximum black and white con-
trast is apparent only in a frontal view.
In the Mountain Plover the social signal function of the facial markings
may be more important than the disruptive coloration function. The black
lore line and black crown patch are conspicuous during the courtship period,
but a molt of the head feathers begins soon after incubation starts and many
individuals lack the bold markings before the end of incubation.
Bock (op. cit.) proposes that the Little Ringed Plover, the Ussuri Sand
Plover (C. placidus), the Wilson's Plover (C. wilsonia) and the Killdeer
currently represent the basic Charadrius stock from which the other species
of Charadrius have radiated. Maclean's (1972) suggestion that species of
Charadrii with reduced clutches have evolved from four egg species does not
conflict with Bock's scheme.
Bock's proposal would suggest that the primitive Charadrius stock had
breast bands, black lore lines and crown patches, since all living members of
his basic stock have these features (Fig. 1). Thus, as species evolved in
habitats with uniform, light colored substrates, selection would have favored
the reduction or complete loss of the breast bands and dark facial marks. This
would explain why the Piping Plover (C. melodus) has only a faint lore line
and sometimes lacks a breast band and why the Kentish Plover, the White-
fronted Plover (C. marginatus), and the Malay Sand Plover (C. peronii)
have an incomplete breast band (Fig. 1)--all nest on light colored substrates.
Since the facial markings of many adults are bright only during the
breeding season and in many species the immatures lack the markings, I
doubt that the lore lines in these species of Charadriinae can serve as sight
lines for capturing prey (Ficken and Wilmot, op. cit.; Ficken et al., op. cit.).
It is hard to conceive that these species require sight lines for feeding only
during the breeding season, especially since other functions appear to exist
for the lore lines at this time.
ACKNOWLEDGMENTS
My Mountain Plover observations were supported by an NIH Training Grant (No. 5
T01 GMO1779) from the National Institutes of General Medical Sciences, a Chapman
Fund Grant, and a Sigma Xi Grant-in-Aid. I thank R. Ryder for making numerous
facilities available to me at Colorado State University and I express my thanks to S.
Derrickson and F. McKinney for critically reading the manuscript. I also thank C. A.
Fleming, J. A. Goodall, M. Howe, G. L. Maclean, and A. R. McGill for allowing me to
use unpublished data. Finally, I thank R. E. Phillips for allowing me to use unpublished
data and for reviewing the manuscript.
LITERATURE CITED
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London.
BENT, A. C. 1927. Life histories of North American shorebirds. Part 2. U.S. Natl.
Mus. Bull., 142.
BLAKER, D. 1966. Notes on the sandplovers (Charadrius) in southern Africa. Ostrich,
37:95-102.
BOCK, W.J. 1958. A generic review of the plovers (Charadriinae: Aves). Bull. Mus.
Comp. Zool., 118:27-97.
BUNNI, n. K. 1959. The Killdeer, Charadrius v. voci]erus Linnaeus, in the breeding
season: ecology, behavior, and the development of homiothermism. Unpubl. Sc.D.
Thesis, Univ. of Michigan Ann Arbor.
CAWKELL, E. M. AND J. E. HAMILTON. 1961. The birds of the Falkland Islands. Ibis,
103a: 1-27.
CONWAY, W. G. AND J. BELL. 1968. Observation on the behavior of Kittlitz's Sand-
plovers at the New York Zoological Park. Living Bird, 7:57-70.
COTT, H. a. 1966. Adaptive coloration in animals. Methuen & Co. Ltd., London.
DEMENT'EV, G. P., N. A. GLADKOV, AND E. P. SPANGENBERG. 1969. Birds of the Soviet
Union. Israel Prog. Sci. Trans., Jerusalem (U.S. Dept. of Commerce, Springfield,
Va.).
DRURY, W. H., JR. 1961. Breeding biology of shorebirds. Auk, 78:176-219.
FIGKEN, R. W., P. E. MATTIIIAE, AND a. HoRwlCtI. 1971. Eye marks in vertebrates:
aids to vision. Science, 173:936-938.
FIeKEN, R. W. AND L. a. WILMOT. 1968. Do facial eye-stripes function in avian vision?
Am. Midi. Nat., 79:522-523.
HALL, K. R. L. 1958. Observations on the nesting sites and nesting behavior of the
Kittlitz's Sandplover (Charadrius pecuarius). Ostrich, 21:112-125.
HILL, R. 1968. Australian birds. Thomas Nelson Ltd., Melbourne.
HUXLEY, J. 1958. Why two breast bands on the Killdeer? Auk, 75:98-99.
JEHL, R. J., JR. 1968. Relationships in the Charadrii (shorebirds): A taxonomic study
based on color patterns of the downy young. San Diego Soc. Nat. Hist., Memoir 3.
JOHNSON, A. W. 1964. Notes on Mitchell's Plover (Phegornis mitchelli). Ibis, 106:
249-250.
JOHNSON, A.W. 1965. The birds of Chile and adjacent regions of Argentina, Bolivia,
and Peru. Platt Est. Graffcos, Buenos Aires.
66 THE WILSON BULLETIN March 1973
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LITTLEJOHNS, R.T. 1932. Notes on four species of Dotterels. Emu, 31:15-20.
MACKWORTH-PRAED, C. W. AND C. H. B. GRANT. 1952. Birds of eastern and northern
Africa. African Handbook of Birds, Series I, Vol. 1. Longmans, Green and Co.,
London.
MACKWORTH-PRAED, C. W. AND C. H. B. GRANT. 1962. Birds of the southern third of
Africa. African Handbook of Birds, Series If, Vol. 1. Longmans, Green and Co.,
London.
MACLEAN, G. L. 1972. Clutch size and evolution in the Charadrii. Auk, 89:299-324.
MACLEAN, G. L., AND V. C. MORAN. 1965. The choice of nest-site in the White-fronted
Plover (Charadrius marglnatus Vieillot.). Ostrich, 36:63-72.
McGIrn, A.R. 1944. The Red-kneed Dotterel in coastal southeastern Australia. Emu,
43:225-228.
McGREGOR, R.C. 1909. A manual of Philippine birds. Part 1. Bureau of Print., Manila.
MEYER DE SCHAUENSEE, R. 1970. A guide to the birds of South America. Livingston
Publ. Co., Wynnewood, Pennsylvania.
OLIVER, W. R.B. 1930. New Zealand birds. Fine Arts Ltd., Wellington.
OLIVER, W. R.B. 1937. The Wrybill Plover. Emu, 37:1-4.
OLIVER, W. R.B. 1955. New Zealand birds. A.H. and A. W. Reed, Wellington.
PARMELEE, D. F., H. A. STEPIIENS, AND R. H. SCHMIDT. 1967. The birds of southeastern
Victoria Island and adjacent small islands. Natl. Mus. Canada, Bull. 222.
PITMAN, C. R. S. 1965. The eggs and nesting habits of the St. Helena Sandplover or
Wirebird, Charadrius pecuarius sanctaehelenae (Harting). Bull. Brit. Ornithol.
Club, 85:121-129.
PORTENKO, L. A. 1963. The ornithology of the Koryak Highlands (U.S.S.R.). Proc.
13th Intematl. Ornithol. Congr., Ithaca, pp. 114(1146.
PULLIAINEN, E. 1970. On the breeding biology of the Dotterel (Charadrius morinellus).
Ornis Fennica, 47:69-73.
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Nat. Hist., 72:143-499.
RITTINGItAUS, H. 1961. Der Seeregenpfeifer (Charadrius alexandrinus). A. Ziemsen
Verlag, Wittenberg, Lutherstadt, Die Neue Brehm-Bucherei.
SERVENTY, D. L. 1943. Hooded Dotterel near Sydney. Emu, 43:72.
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Vol. 24. Longroans and Co., London.
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rius marginatus) at Gamtoos River mouth in 1950. Ostrich, 22:117-119.
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191-207.
SIMMONS, K. E. L. 1953b. Some aspects of the aggressive behavior of three closely
related plovers (Charadriidae): Little Ringed, Kentish, and Ringe& Ibis, 95:115-
127.
SUTTON, g. M. AND D. F. PARMELEE. 1955. Breeding of the Semipalmated Plover on
Barfin Island. Bird-Banding, 26:137-147.
TINBERGEN, N. 1953. Social behaviour in animals. John Wiley and Sons, Inc., New
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WETMORE, A. 1965. Water, prey, and game birds of North America. Natl. Geogr.
Soc., Washington.
Wn. cox, L. 1959. A twenty year banding study of the Piping Plover. Auk, 76:129-152.
W.ter CHARADRIINAE HEAD AND BREAST MARKINGS 67
D. Graul
WINTERBOTTOM, J. M. 1963. Comments on the ecology and breeding of Sandplovers
(Charadrius) in southern Africa. Rev. Zool. Bot. Africaines, 67:11-16.
WITHERBY, H. F., F. C. R. JOURDAIN, N. F. TICEtlURST, AND B. W. TUCKER. 1941. The
handbook of British birds. Vol. 4. H.F. and G. Witherby Ltd., London.
APPENDIX I
SEASONAL, SEXUAL, ANI) ACE PLUMACE DIFFERENCE IN CHARADRIINAE
Sexual Plumage Immature Plumage
Differences Breeding Plumage Different than
in Breeding Brighter than Adult Breeding
Species Season Non-breeding Plumage References*, **
Charadrius hiaticula Yes No Yes 1, 5
C. semipalmatus Yes Yes Yes 30, 31
C. placidus Yes Yes Yes 5
C. dubius Yes Yes Yes 1, 31
C. wilsonia Yes Yes Yes 2, 30
C. voci]erus No No Yes 2, 30
C. melodus Yes Yes Yes 2, 30
C. thoracicus ? ? ? 3, 27
C. pecuarius No No Yes 4, 16, 17
C. sanctaehelenae No ? Yes 25
C. tricollaris Yes ? Yes 16, 29
C. alexandrinus Yes Yes Yes 28, 30
C. marginatus Yes Yes Yes 15, 29
C. peronii Yes Yes Yes 12, 20, 29
C. venustus Yes ? Yes 16
C. collaris Yes Yes Yes 9, 23
C. bicinctus Yes Yes Yes 8, 23
C. ]alklandicus Yes Yes Yes 9, 12, 13, 29
C. mongolus Yes Yes Yes 5, 26
C. leschenaultii Yes Yes Yes 5, 15
C. asiaticus Yes Yes Yes 1, 5
C. veredus Yes Yes Yes 5, 21
C. modestus No Yes Yes 6, 13, 29
68 THE WILSON BULLETIN March 1973
Vol. 85, No. 1
APPENDIX I--Continue'd
Sexual Plmnage hmnature Plmnage
Differences Breeding Plmnage Different than
in Breeding Brighter than Adult Breeding
Species Season Non-breeding Plumage References*, * *
C. montanus Yes Yes Yes 10
C. melanops Yes Yes Yes 11, 14, 19, 29
C. cinctus No No Yes 18, 19, 29
C. rubrlcollls No No Yes 14, 19, 29
C. novaseelandiae Yes No Yes 8, 23, 24
Anarhynchus Jrontalis Yes Yes Yes 22, 23
Phegornis mitchelli Yes ? Yes 6, 9, 13, 29
Pluvialis apricaria Yes Yes Yes 1, 31
Phtvialis dominica Yes Yes Yes 2, 7, 30
Pluvialis squatarola Yes Yes Yes 2, 30
Pluvialis obscura Yes Yes Yes 23, 29
Eudromias morlnellus Yes Yes Yes 1, 31
Oreopholus ruficollis No ? ? 6, 9, 13, 17
Pluvianellus socialis No ? Yes 6, 9, 12, 13
* Gooders, J. 19.69. Birds of the world, Vol. 3 (Parts 6 and 7), IPC Magazines Ltd., London.
Contains photographs and drawings of most Charadriinae species and is used here as a general
reference.
** References listed in Appendix I as follows:
13. Johnson (1965) 22. Oliver (1937)
14. Littlejohns (1932) 23. Oliver (1955)
15. Mackworth-Praed and 24. Phillips, R. E.
(pets. comm. )
1. Bannerman (1961)
Bent (1929)
3] Bock (1958)
4. Conway and Bell (1968)
5. Dement'ev et al. (1969)
6. Meyer de Schauensee (1970)
7. Drury (1961)
8. Fleming, C. A. (pers. comm.)
9. Goodall, I. A. (pers. comm.)
10. Graul, W. D. (pers. ohs.)
11. Hill (1968)
12. Howe, M. (pers. comm.)
Grant (1952)
16. Mackworth-Praed and 25. Pitman (1965)
Grant (1962) 26. Portenko (1963)
17. Maclean, G.L. 27. Rand (1936)
28. Rittinghaus ( 1961 )
(pers. comm. )
18. McGill (1944) 29. Sharpe (1896)
19. McGill, A. R. (pers. comm.) 30. Wetmore (1965)
g0. McGregor (1909) 31. Witherby et al.
21. Oliver (1930) (1941)
Walter CHARADRIINAE HEAD AND BREAST MARKINGS 69
D. Graul
APPENDIX II
BREAST B^ND PaZSZNCE, M^N NEST SITE, AND NEST SITE REFERENCES
Breast Band Nest Site
Species (X = Present) Main Nest Site* References**
Charadrius hiaticula X Shingle (1) 1, 33
C. semipalmatus X Shingle (1) 8, 29
C. placidus X Shingle (1) 6
C. dubius X Shingle (1) 1, 28, 33
C. wilsoaia X Sand (frequently near 2, 30
dark objects) (3)
C. voci]erus X Shingle or disturbed areas (1) 4, 8
C. melodus Usually Sand (2) 2, 31
C. thoracicus X Sub-desert ( ? ) 24
C. pecuarius Sand (2) 9, 32
C. saactaeheleaae Grasslands (2) 21
C. tricollaris X Shingle, dried mud (1) 3
C. alexaadriaus incom. Sand, salt flats (2) 12, 25
C. margiaatus incom. Sand (near objects) 14, 27
or shingle (3)
C. peroaii incom. Sand (near drift) (3) 17
C. veaustus X Salt pans (2) 3, 13
C. collars X Sand, river beds ( ? ) 7
C. biciactus X Shingle, disturbed 19
areas, sand (1)
C. ]alklaadicus X Sand, short grass (2) 5, 15
C. mongolus Stony tundra (1) 6, 22
C. lescheaaultii Stony areas (1) 6
C. asaticus X Arid grasslands (commonly 6, 33
among pieces of clay) (1)
C. veredus X Stony areas (1) 6
C. modestus X Arid grasslands (2) 5
C. moataaus Arid grasslands (2) 8
C. melaaops X Shingle, dried mud, sand (1) 12, 19
C. ciactus X Sand (commonly near 16
shrubs) (3)
C. rubrlcollis incom. Sand (near sea drift 26
commonly) (3)
March 1973
70 THE WILSON BULLETIN Vol. 8a, No. 1
ArrENDIX II---Continued
Breast Band Nest Site
Species (X ----Present) Main Nest Site* References**
C. novaseelandiae Holes or crevices (2) 19
Anarhynchusfrontalis X Shingle (1) 18, 19
Phegornis mitchelli X Shingle or rocky sand areas (1) 10, 11
Pluvialis apricaria Moors (2) 1, 33
Pluvialis dominica Stony tundra (1) 8, 20
Pluvialis squatarola Stony tundra (1) 8, 20
Pluvialis obscura Sand (2) 19
Eudromias morinellus X Arid areas (commonly stony) (1) 1, 23
Oreopholus ruficollis Arid grassland (2) 11
Pluvianellus socialis Sand (sometimes near rocks) (3) 11
* ( 1 ) ---- Nest site considered discontinuous.
(2 / ---- Uniform nest site substrates.
( 3 = Nest sites near conspicuous dark objects on an other;vise uniform substrate.
** References in Appendix II:
1. Bannerman (1961) 12. Littlejohns (1932) 22. Portenko (1963)
2. Bent (1929) 13. Mackworth-Praed and 23. Pulliainen (1970)
3. Blaker (1966) Grant (1962) 24. Rand (1936)
4. Bunni (1959) 14. Maclean and Moran 25. Rittinghaus (1961)
5. Cawkell and Hamilton (1965) 26. Serventy (1943)
15. Maclean, G.L. 27. Shewell (1951)
(1961)
6. Dement'ev eta]. (1969) (pers. comm.) 28. Simmons (1953a)
7. Meyer de Schauensee 16. McGill ( 1944 ) 29. Sutton and Parmelee
(1970) 17. McGregor ( 1909 ) (1955)
8. tra,d, W. D. (pets. obs.) 18. Oliver (1937) 30. Tompkins (1944)
9. Hall (1958) 19. Oliver (1955) 31. Wilcox (1959)
10. Johnson (1964) 20. Parmeleeetal. (1967) 32. Winterbottom (1963)
11. Johnson (1965) 21. Pitman (1965) 33. Witherby et al. (1941)
JAMES FORD BELL MUSEUM OF NATURAL HISTORY, UNIVERSITY OF MINNESOTA
MINNEAPOLIS, MINNESOTA 55455, 7 SEPTEMBER 1972.