Long-term consistency in susceptibility of prey species to predation by an avian predator

Selection by predators affects prey through competition for limiting resources. This not only has consequences for direct mortality but also indirectly affects disturbance. Changes in the intensity of selection on prey by predators may affect the size of prey populations, with consequences for their short- or long-term interactions. We assessed whether predation by northern goshawks Accipiter gentilis modified the composition of prey communities consistently along a temporal gradient, showing long-term consistency in susceptibility of prey species to predation. We followed six populations of the goshawk in two biomes in Denmark and Finland during 1949-2019. Susceptibility to goshawk predation in 2005-2017 in Denmark was only weakly related to susceptibility to goshawk predation in 1977-2004. In Finland, susceptibility of shared prey species to goshawk predation was positively related between periods. The average difference in susceptibility to goshawk predation between periods was considerably higher in Denmark than in Finland. Susceptibility of prey species to predation in goshawks increased with latitude and body mass of prey species, and decreased with period of time and population density of prey species. The changes in susceptibility to predation suggest changes in the characteristics of the local prey pools.