A Red-crowned Woodpecker (Melanerpes rubricapillus), observed in Venezuela, roosted in a pendulous icterid nest. Such a roost site has not been reported previously. Variability of entry time was not significantly different than variability of departure time. Mean roosting time was shorter than the mean night period. The behavior of this woodpecker suggests flexibility in roost-site selection.
Canadian Wildlife Service
Room 210, d999-98 Avenue
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LUGAR DE PERNOCTAR POCO USUAL PARA MELANERPES RUBRICAPILLUS
EN VENEZUELA
Resumen.--Un individuo de Melanerpes rubricapillus fue observado pernoctar en un nido
en forma de pgndulo perteneciente a un ictgrido. Durante cuatro das el ave utiliz6 el nido
para pernoctar. No hubo diferencias significativas entre las horas de entrada en las noches
y salidas en las marianas. E1 patr6n de conducta de este pjaro carpintero nunca antes haba
sido informado en la literatura y sugiere flexibilidad en la selecci6n de treas de pernoctar
por parte de estas aves.
Woodpeckers usually roost in tree cavities (see Bent 1939, Short 1982).
In this note, I describe the behavior of a male Red-crowned Woodpecker
(Melanerpes rubricapillus) using a previously unreported type of roost
site. Observations were made between 12 and 30 Oct. 1986 and over 7.4
h with the aid of a spotting scope and 8 x 30 binoculars from the second
and third floor of a hotel in Maracaibo, Venezuela. Monitoring began
6-31 min before roost departure and up to 23 min before roost entry.
On 12 Oct. 1986, I saw a male Red-crowned Woodpecker clinging to
the side of an unoccupied icterid nest, possibly that of a Yellow Oriole
(Icterus nigrogularis). The nest was suspended about 16 m above ground
in an Apamate tree (Tabebuia rosea (Bertol)). The woodpecker entered the
pendulous nest about 1828 and looked out of the nest entrance for most
of the remaining 17 min during which I watched. Oncoming darkness
made observation difficult, but since the bird made no effort to leave, I
suspected that the nest was being used as a roost site. The following
morning at 0627 a bird, believed to be the same individual left the nest.
Again, poor light made identification difficult, but a dark bill and brown
head were noted and a few minutes later a male Red-crowned Woodpecker
was observed preening itself on a nearby limb. This roost was used by a
Red-crowned Woodpecker, probably the same bird, for at least five nights
(12, 14-17 Oct.). On at least two occasions a male was seen entering or
leaving the nest. From observations made on the evenings of 18, 29, and
30 Oct., it appeared that the roost was not in use.
The average entry time was 1827 (SD = 5.0 min, n = 4) and the mean
morning departure time from the roost was 0627 (SD = 4.6 min, n --
5). Departure from the roost site was in the same direction and usually
rapid. The variability of entry times was not significantly different from
the variability of departure times (P > 0.05, Squared Ranks Test). The
woodpecker entered the nest on the average 14.8 min (SD = 5.0 min, n
= 4) before sunset and departed from the nest on average 4.8 min (SD
= 4.9 min, n = 5) after sunrise. Roosting time (final entry to departure)
averaged 718.0 min (SD = 4.8 min, n = 4) and was about 22 min shorter
than the mean night period (sunset to sunrise) during 12-18 Oct., which
was 739.5 min (SD = 1.0 min).
Skutch (1969) found that a male Red-crowned Woodpecker in Costa
Rica during October frequently went to roost "an hour or more before
nightfall." This is in contrast to the behavior of the male I observed in
Venezuela which, during the same month but a different year, entered
the roost nest less than 20 min before sunset. Also in Venezuela, Fried-
mann and Smith (1950) observed an individual going into an excavated
tree cavity "Early in April... regularly at sundown, apparently to pass
the night." In Costa Rica, Skutch (1969) observed another male enter its
roost following sunset in February. Kilham (1972) noted two roost
entry times in Panama, one at about 1740 and the other at 1820, 10 min
after the bird's arrival at the roost tree. The latter entry time may have
been influenced by the presence of other wildlife (Kilham 1972).
To my knowledge there are no published reports of picids roosting in
suspended cupped nests (Pettingill 1970) of icterids. In Costa Rica (Skutch
1969) and Panama (Kilham 1972), Red-crowned Woodpeckers roost in
tree cavities. Friedmann and Smith's (1950) observations at one site,
suggest this may be true in Venezuela as well. Males, unlike females,
excavate roosting cavities for themselves and these "dormitories" are usu-
ally more secure than roost sites chosen by females (Skutch 1955). The
height above ground of the roost nest described in this note falls within
the range (6-18 m) of dormitories seen by Skutch (1969) in Costa Rica.
The roost site described in this note is unusual in that it was not in a
tree cavity and excavation was not required for its use. The male Red-
crowned may have been opportunistic in his selection of a roost. Although
both sexes were observed on the roost tree, two birds never entered the
roost nest. These observations are consistent with those of Skutch (1969)
who found that males and females roost separately. My observations also
indicated that the bird roosted with its head near the opening of the
entrance, a position facilitating escape behavior in the event of a predator's
attack.
ACKNOWLEDGMENTS
These observations were made during my participation in the Latin American Program
of the Canadian Wildilfe Service. I thank Clark Casler and Wilmer Villalobos for suggesting
a possible identification of the icterid nest and Clark Casler for identifying the tree from
which it was suspended. W. Prusak of Atmospheric Environment Canada kindly provided
me with the sunrise-sunset data and Sam Barry gave statistical advice. I thank Ursula
Banasch, Sam Barry, E. H. Burtt, Jr., Lawrence Kilham and an anonymous referee for
their comments, which helped improve this note.
LITERATURE CITED
BENT, A. C. 1939. Life histories of North American woodpeckers. U.S. Nat. Mus. Bull.
174.
FRIEDMANN, H. AND SMITH, F. D. JR. 1950. A contribution to the ornithology of north-
eastern Venezuela. Proc. U.S. Nat. Mus. 100:411-538.
KILH^M, L. 1972. Shortness of tail in Red-crowned Woodpeckers and their habit of
entering roost holes backward. Condor 74:202-204.
PETTINGILL, O. S., JR. 1970. Ornithology in laboratory and field. Fourth ed., Burgess
Publishing Co. Minneapolis. 524 pp.
SHORT, C. L. 1982. Woodpeckers of the world. Delaware Museum of Natural History.
676 pp.
SKUTCH, A. F. 1955. The Hairy Woodpecker in Central America. Wilson Bulletin 67:
25-32.
1969. Life histories of Central American Birds, III. Pacific Coast Avifauna No.
35.' 580 pp.
Received 10 Sep. 1987; accepted 8 Jun. 1988.