This discussion was first published as part of the 2013 Red List update, but remains open for comment to enable reassessment in 2015.
Rufous-tailed Hawk Buteo ventralis is restricted to the lower Andes of Patagonia in southern Chile and Argentina, where it is rare, occurring at naturally low densities. It is currently listed as Near Threatened because it was thought to have a small global population, approaching the threshold for Vulnerable under criterion D1 (<1,000 mature individuals). The population is suspected to be stable despite the fact that the destruction of its habitat is ongoing.
No data is available regarding numbers or densities for this species, and there is no firm evidence of a decline, but its habitat has suffered extensive degradation and some authorities consider that the total population is unlikely to exceed 1,000 individuals (Ferguson-Lees and Christie 2001). The total population is currently placed in the band 250-999 mature individuals, equating to 375-1,499 individuals in total, rounded to 350-1,500 individuals. If this is confirmed, this species would warrant uplisting to Vulnerable under criterion D1 of the IUCN Red List, on the basis that the global population is estimated to be fewer than 1,000 mature individuals. Any evidence of continuing declines in the population could make the species eligible for classification as Endangered under criterion C2a (i or ii) depending on the subpopulation structure.
Further information is required regarding population size, trends and other potential or existing threats, and comments on the proposed uplisting are welcome.
Ferguson-Lees, J. and Christie, D. A. (2001) Raptors of the world. Christopher Helm: London.