Breeding Distribution and threats for the Black-and-chestnut Eagle in Argentina

GRANDE, J. M.; ARÁOZ, R.; SALOM, A.; ZULUAGA, S.

Albuquerque

Congreso; Raptor Research Annual Conference; 2023

Raptor Research Foundation

The Black-and-Chestnut Eagle (Spizaetus isidori) was first discovered in Argentina in 1954 through a collected individual. Another individual was collected in 1956, then, with no records for 30 years the species was considered locally extinct in 1985. However, in July of 1987 the species was recorded again. Since then, several records indicated that this endangered species was distributed through the Yungas of Argentina. In 2014, the first nest was found. Here we report data on breeding ecology, diet, dispersal and potential threats gathered in that single nest for eight years, as well as the finding of eight additional nests of this species. The Black-and-Chestnut Eagle has been confirmed to nest in three of the four provinces with Yungas forest of Argentina. Its nesting season may start from late April to the first week of August and ends from mid-September to late December. The breeding rate was 0.71 nestlings/nest/year in the first nest, but with additional nests the breeding rate dropped to 0.47. This species feeds mostly on guans and eventually chickensand other raptors. Data gathered in the last years suggest that unnoticed human mediated mortality could be higher than expected. The dispersal movement of juveniles suggests the eagles can move through large areas but they suffer a high mortality. The monitoring of new nests will improve ourunderstanding on the species ecology and its conservation status in northern Argentina.