Factors affecting carcass detection at wind farms using dogs and human searchers.
Abstract
The use of detection dogs to effectively monitor bird and bat fatalities at wind farms is becoming increasingly popular. All studies to date agree that dogs outperform human searchers at finding bird and bat carcasses around wind turbines; however, it remains unclear how characteristics of the carcass and environmental conditions during the search may influence detection. We investigate the effect of carcass size, vegetation characteristics and weather conditions on the probability of detecting a carcass, for both dogs and humans, using data from the monitoring program of a wind farm in Spain. A generalized linear mixed model reveals a high performance of dogs (~80% detection rate), with no clear influence of any of the variables analysed. Humans, on the contrary, were markedly affected by the size of the carcass and to some extent, by the vegetation structure. Humans performed poorly at detecting small carcasses (~20% detection rate), more so in closed vegetation. Synthesis and applications. Our results provide evidence that dogs perform with high success rates at detecting bird and bat carcasses of different sizes under a wide range of environmental conditions. Humans, by contrast, were very poor at detecting all but the largest carcasses in open areas. We find the use of detection dogs at wind farms to be a robust and cost-effective alternative to using human searchers, most notably, when the focus is on the monitoring of fatalities of small, rare or inconspicuous species in closed vegetation.