Effects of climate variation on bird escape distances modulate community responses to global change

Abstract

Climate and land use are rapidly changing environmental conditions. Behavioral responses to such global perturbations can be used to incorporate interspecific interactions into predictive models of population responses to global change. Flight initiation distance (FID) reflects antipredator behaviour defined as the distance at which an individual takes flight when approached by a human, under standardized conditions. This behavioural trait results from a balance between disturbance, predation risk, food availability and physiological needs, and it is related to geographical range and population trends in European birds. Using 32,145 records of flight initiation distances for 229 bird species during 2006–2019 in 24 European localities, we show that FIDs decreased with increasing temperature and precipitation, as expected if foraging success decreased under warm and humid conditions. Trends were further altered by latitude, urbanisation and body mass, as expected if climate effects on FIDs were mediated by food abundance and need, differing according to position in food webs, supporting foraging models. This provides evidence for a role of behavioural responses within food webs on how bird populations and communities are affected by global change.

Lockdown effects on fear: direct and indirect effects mediated by release of urban predators

“…urban parks). We were thus able to sample during (2020) and after (2021) the Covid-19 lockdown in the same areas that we sampled before lockdown (2018) in previous studies (Díaz et al 2013;2021;.…”

Mesocarnivore Distribution along Gradients of Anthropogenic Disturbance in Mediterranean Landscapes

“…Responses of predators to global change may have cascading effects on prey communities well beyond the direct effects of global change drivers on prey [1]. For instance, direct interactions between humans and large carnivores, in the form of persecution and extermination of the top predators competing with human interests, tend to favour the expansion of mesocarnivores (mesopredator release hypothesis) [2].…”

“…Here, we analyse the distribution patterns of mesocarnivores along the gradients of anthropogenic disturbance found in Mediterranean landscapes and discuss the potential cascading effects of these patterns on the long-term trajectories of these landscapes [19]. Our aim is to predict the responses of Mediterranean systems to global change beyond current simplistic niche modelling approaches [1]. We predicted that responses of mesocarnivores along these anthropogenic gradients will depend on the perceived suitability of such gradients by the target species.…”

Mesocarnivore distribution along gradients of anthropogenic disturbance in Mediterranean landscapes

“…Responses of predators to global change may have cascading effects on prey communities well beyond direct effects of global change drivers on prey [1]. For instance, direct interactions between humans and large carnivores, in the form of persecution and extermination of the top predators competing with human interests, tend to favour the expansion of mesocarnivores (mesopredator release hypothesis) [2].…”

“…Here we analyze patterns of distribution of mesocarnivores along the gradients of anthropogenic disturbance found in Mediterranean landscapes and discuss the potential cascading effects of these patterns on the long-term trajectories of these landscapes [16]. Our aim is predicting responses of Mediterranean systems to global change beyond current simplistic niche modelling approaches [1]. We predicted that responses of mesocarnivores along these anthropogenic gradients will depend on the perceived suitability of such gradients by the target species.…”