Assessing the introduction of exotic raptors into the wild from falconry

Abstract

Falconry may constitute a source of exotic species through the escape into the wild of individuals kept in captivity. The introduction of top predators can have important ecological consequences for the recipient community, including genetic pollution through reproduction between falconry hybrids and wild raptors. Here we assessed the introduction of falconry raptors (both native and exotic) into the wild between 2006 and 2018 through reports of lost, stolen and recaptured birds on a website widely used by the falconer community in Spain. Exotics were 60.9% of the 1995 raptors reported as escaped in the wild (mean rate: 76.7 individuals per year) belonging to 33 species (or subspecies not native to the study area) and 27 hybrid morphs. Escapes, which numbers show a quadratic trend along years with maximums between 2010 and 2012, were aggregated in the most populated areas. The main cause of these escapes was the use of defective materials by the falconers. Although people devote much effort to ensuring that their birds are not lost, 64.3% of escaped raptors were unrecovered, and recapture rates were lower for native raptors (29.9%) compared to exotics (39.4%). Harris’s hawk was the most frequently introduced species (i.e., unrecovered), followed by peregrine falcons and hybrids. This study quantifies for the first time the introduction rate of exotic raptors in the wild from falconry and proposes measures to regulate and improve this practice.