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Providing evidence to improve practice

Individual study: Survival rates and range sizes of aplomado falcons Falco femoralis hacked at a wetland site in Texas, USA

Published source details

Perez C.J. & Zwank P. (1996) Survival, movements and habitat use of aplomado falcons released in southern Texas. The Journal of Raptor Research, 30, 175-182


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Release captive-bred individuals into the wild to restore or augment wild populations of raptors Bird Conservation

A replicated study in 1993-4 (Perez & Zwank 1996) found that four-week survival rates of captive-bred aplomado falcons Falco femoralis hacked at a wetland site in southern Texas, USA, ranged from 58% (five known mortalities from 12 birds released in 1994) to 85% (four known mortalities from 26 birds released in 1993). Predation by great horned owls Bubo virginianus and coyotes were the main causes of mortality. Released birds had larger range sizes than predicted, which the authors suggest is due to birds having expanded ranges before pairing up. Birds were transported to the release site when four weeks old and fed there before being released at 37 days old. Food was then provided until birds no longer returned to feed.