Climate change and human disturbance can lead to local extinction of Alpine rock ptarmigan: new insight from the western Italian Alps

PLoS One. 2013 Nov 19;8(11):e81598. doi: 10.1371/journal.pone.0081598. eCollection 2013.

Abstract

Alpine grouses are particularly vulnerable to climate change due to their adaptation to extreme conditions and to their relict distributions in the Alps where global warming has been particularly marked in the last half century. Grouses are also currently threatened by habitat modification and human disturbance, and an assessment of the impact of multiple stressors is needed to predict the fate of Alpine populations of these birds in the next decades. We estimated the effect of climate change and human disturbance on a rock ptarmigan population living in the western Italian Alps by combining an empirical population modelling approach and stochastic simulations of the population dynamics under the a1B climate scenario and two different disturbance scenarios, represented by the development of a ski resort, through 2050.The early appearance of snow-free ground in the previous spring had a favorable effect on the rock ptarmigan population, probably through a higher reproductive success. On the contrary, delayed snowfall in autumn had a negative effect possibly due to a mismatch in time to molt to white winter plumage which increases predation risk. The regional climate model PROTHEUS does not foresee any significant change in snowmelt date in the study area, while the start date of continuous snow cover is expected to be significantly delayed. The net effect in the stochastic projections is a more or less pronounced (depending on the model used) decline in the studied population. The addition of extra-mortality due to collision with ski-lift wires led the population to fatal consequences in most projections. Should these results be confirmed by larger studies the conservation of Alpine populations would deserve more attention. To counterbalance the effects of climate change, the reduction of all causes of death should be pursued, through a strict preservation of the habitats in the present area of occurrence.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Climate Change
  • Computer Simulation
  • Conservation of Natural Resources*
  • Ecosystem
  • Female
  • Galliformes / physiology*
  • Humans
  • Italy
  • Male
  • Models, Statistical*
  • Population Dynamics
  • Predatory Behavior
  • Seasons
  • Snow

Grants and funding

This research was supported by the EU Interreg ALCOTRA Project "Galliformi Alpini" and by the Italian Ministry of Education, University and Research through the PRIN Project 2010-2011 "Climate change and animal populations: predictive models for mammals and birds" (20108 TZKHC) and the Project of Interest "NextData" (PNR 2011-2013). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.