22 July, 2023
By Brayan Eberth Zambrano Gómez
Rufous tailed Hawk (Buteo ventralis) in Valdivia, Chile. Photo by Brayan Zambrano.
Endemic to the temperate forest of the southern Andes mountains of Chile and Argentina, the Rufous-tailed Hawk (Buteo ventralis) is currently listed by the IUCN as vulnerable to extinction. With an estimated global population of fewer than 1,000 mature individuals, this species is considered one of highest conservation priorities for raptors in Chile.
As top predators, Rufous-tailed Hawks play an important ecological role by preying on granivorous species considered pests, including birds that eat agricultural crops, which cause economic damage to farmers. This means that the threats to Rufous-tailed Hawks also undermine the ecosystem services these raptors provide to people.
Rufous-tailed Hawk dark morph (left) and light (typical) morph (right). Photos by Brayan Zambrano.
By regulating herbivorous prey species, Rufous-tailed Hawks influence primary production and play a key role in the regeneration of the forest ecosystems they inhabit. Breeding pairs mainly use emergent trees to support their nests, both in temperate forests and exotic tree plantations. Logging is one of the main threats to its populations.
Temperate native pine forest fragments and exotic Eucalyptus plantation in Chile. Photo by Brayan Zambrano.
To date, there have been no systematic studies investigating Rufous-tailed Hawk nest site selection or productivity (the number of chicks that successfully leave the nest) in sites with native temperate forest compared with exotic tree plantations. With a grant from IBCP, I am conducting research to address this knowledge gap in Chile’s Los RÃos Region.
Brayan Zambrano with a banded dark morph Rufous-tailed Hawk. Photo courtesy of Brayan Zambrano.
To help obtain preliminary information on nest locations, we have distributed posters to educate people on Rufous-tailed Hawks identification. Through this project, we will investigate the proportions of native forest and exotic tree plantations associated with Rufous-tailed Hawk nesting habitat and productivity, as well as the ages of exotic tree plantations used for nesting.
Brayan Zambrano at a sampling site, climbing to the canopy to identify nests. Photo courtesy of Brayan Zambrano.
We expect results of this project to contribute to conservation planning and actions such as the protection of nesting trees, the installation of artificial nests in areas protected from logging, and the translocation of nestlings to areas protected from logging to prevent the destruction of nests and the death of nestlings. We will also seek to determine the minimum amount of native forest cover required for Rufous-tailed Hawks to nest successfully.
Informational poster on the search for Rufous-tailed Hawks nests. Poster courtesy of Brayan Zambrano.