femaleP1
male (with blue stripe under caruncle visible)P2
femaleP1 |
male (with blue stripe under caruncle visible)P2 |
Breeding male is almost completely black with greenish caruncles over the eye and a blue stripe (often hidden) between caruncle and eye. In non-breeding males the feathers are outlined with green, as the breeding season approaches the green edgings fade and the caruncles appear. Female (and predefinite (ie. sub-adult) male) has olive-green plumage with pale yellow blotches on underparts. Birds mass about 40g. (Prum 1997)
The breeding male's caruncles have a microscopic structure designed to reflect UV light indicating that birds make use of UV coloration. (Prum 1999)
P. castenea males molts once in the year Feb-May producing the non-breeding plumage of black feathers edged with green. As the year progresses the green edgings wear off to produce a velvety black plumage. There is no molt to produce the breeding plumage. I can find no data on female molting. In RNP caruncles appear in the males in Oct-Nov (in other more northerly areas this occurs earlier). Males start defending territories around the end of November and continue to do so into February. Females (or birds with female plumage) start to construct nests in November and continue into December. (Prum 1997). Nests have been found with eggs in them on 15 Jan (Kaplan, video tape data, 1999), and with fledglings on 19 Jan (Kaplan, video tape data, 1999) and 26 Jan (Prum 1997).
P. castenea is primarily frugivorous, but in times of fruit scarcity it will also feed on nectar. It (like Microcebus and Propithecus) is fond of the nectar from the Mistletoe Bakerella sp. (Prum 1997)
During the breeding season (starting around Nov) the males defend small (10-20m diameter) territories in which they display. Territories are usually close to other males' territories (distance between centers < 50m) with males within hearing of each other. Almost all foraging is done outside of the territory. Males are polygynous. Males display and call within their territories. Thus this is a distributed lek breeding system. Some males have used the same territory in two breeding seasons (insufficient data are available to determine if this is common), but the territory is only defended in the breeding season.. (Prum 1997)
Females build nests just outside of male territories. Prum usually observed 2 female plumaged birds building each nest but was not sure whether one might be a non-definite male, definite males were not observed to build nests. All nests were constructed in Tambourissa obevata: Monimiaceae trees, the same tree will often be used for several years. Nests are made of moss and green plant matter and are approximately 25cm tall and 12cm in diameter and take more than 10 days to build. (Prum 1997)
Fledglings have female-type plumage and are fed exclusively by females. (Prum 1997)
Asity female in and around
nestP3
Velvet Asity
EggP4
nestlingP5
Asity maleP6
1.7Mb
V1
2.4Mb
V2
.8Mb
V3
1.9Mb
V4
1.2Mb
V5
.6Mb
V6
.6Mb
V7
Goodman SM, Putnam MS, 1996, "The birds of the eastern slope of the Reserve Naturalle Intégrale d'Andringitra", Fieldiana: Zoology, new series No. 85
Langrand, Olivier; 1990: Guide to the Birds of Madagascar, Yale University Press
Prum RO, Razafindratsita VR; 1997 "Lek behavior and natural history of the Velvet Asity (Philepitta castenea: Eurylaimidae)", Wilson Bulletin, 109:(3) 371-392
Prum RO, Torres R, Kovach C, Williamson S, Goodman SM; 1999, "Coherent light scattering by nanostructed collagen arrays in the caruncles of the Malagasy asites (Eurylaimidae: Aves)", Journal of Experimental Biology, 202:(24) 3507-3522
Sinclair, I & Langrand, O.; 1998: Birds of the Indian Ocean Islands, Struik