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NESTING OF THE PURPLE‐THROATED CARIB HUMMINGBIRD
Author(s) -
Wolf Larry L.,
Wolf Janet S.
Publication year - 1971
Publication title -
ibis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.933
H-Index - 80
eISSN - 1474-919X
pISSN - 0019-1019
DOI - 10.1111/j.1474-919x.1971.tb05160.x
Subject(s) - nest (protein structural motif) , hummingbird , avian clutch size , biology , ecology , zoology , incubation , parus , nectar , reproduction , pollen , biochemistry
SUMMARY We present data on certain parts of the nesting biology of the Purple‐throated Carib Humming‐ bird Eulampis jugularis on the island of Dominica, British West Indies. We watched two nests with eggs and young and a single nest under construction. Incubation was in short periods averaging about six minutes. Females at both nests with eggs continued adding material to the nest until the end of incubation. We suggest that this common practice among hummingbirds may insure that a limited amount of energy at the time of initial nest‐building and egg‐production is optimally apportioned between the two activities. Brooding ceased in one nest when the young were about 13 days old. Feeding rates stayed relatively constant at one to two per hour throughout the nearly complete nestling period in one nest. Average time per feeding declined, apparently as the female‐young interaction became more efficient with maturation of the young. Nesting females foraged on both insects and nectar. We could not be sure what they were feeding the young. Defence of the nest varied with the position of the female and the type of intruder. The aggressive behaviour associated with defence varied according to the size and type of intruder. We concluded that for the one nest of Eulampis for which we had the most complete data, had there been three young, the female would have been unable to provide sufficient food to nourish them. However, the universal clutch size of two and nearly universal promiscuity in humming‐ birds is strong evidence that factors other than the ability of adults to feed more than two young are important in determining clutch size.