NESTING BIOLOGY OF THE BLACK-THROATED TODY-TYRANT (HEMITRICCUS GRANADENSIS) WITH NOTES ON MATING DISPLAYS

摘要

There is limited information on the breeding biology of members of the speciose genus Hemitriccus (Aves: Tyrannidae), published nest descriptions exist for only six of the 22 species. The Black-throated Tody-Tyrant (Hemitriccus granadensis) is one of these species that lacks information regarding its nesting biology. We provide the first nest, egg, nestling, and incubation behavior descriptions for the species with notes on its courtship behavior. We found three nests and observed one courtship display at three field sites, two in Colombia and one in Peru. The nest of H. granadensis is an enclosed "purse-like" pendant pouch inside of a moss ball suspended from a small branch with a side entrance and obscured by vegetation. Two nests had a single egg, which averaged 18.1 × 12.9 mm and 1.55 g. Egg appearance varied between nests, the egg at the Colombian site was tan and unmarked, whereas the egg at the Peruvian site was bright white with a few scattered, red specks. We cannot describe the full incubation period or nestling period because of egg infertility and nestling death. However, one nest was discovered with an egg that was incubated for 19 days. Nest attentiveness was 77.5% and average inner nest temperature differed between the Colombian (±SD) (23.79 ± 1.5℃) and Peruvian (17.27 ± 1.54℃) nests. We provide observations and video footage of the courtship display that match previous observations of this species. Overall, the nest shape resembles those of other Hemitriccus species, but clutch size differs from information published for the genus.