ESR 3:69-76 (2007)  -  doi:10.3354/esr003069

ABSTRACT: Ecological traps, in combination with other factors, can reduce population sizes and even lead to local extinction. Here, we present the first evidence that hunting sites can act as ecological traps for waterfowl: wintering common coots Fulica atra were preferentially attracted to hunting sites in southern European wetlands, and showed decreasing population trends in these sites, compared to non-hunting sites. We demonstrate that the supply of energy-rich supplementary food (grain) triggered the trap. We also show that a behavioural mechanism, acting as an evolutionary load (the tendency to form mixed coot flocks during the winter), decreased population size of a threatened waterfowl species, the crested coot F. cristata. Our results suggest the use of precautionary policies regarding supplementary food in coot and associated diving-duck species, if negative conservation impacts are to be avoided.

KEY WORDS: Ecological trap · Evolutionary load · Management · Waterfowl hunting · Wetlands · Conservation · Coots · Supplementary feeding