The impact of vacation homes on bird nest predation

Vacation homes may be harming some birds through increased nest predation, according to the findings in a new study in the journal of European Wildlife Research.

While suburban sprawl receives close scrutiny for its negative environmental impacts, vacation homes and other low density housing in more pristine areas are often overlooked.

However, as Ole-Gunnar Støen and fellow researchers in Norway show, these homes can negatively impact birds by attracting generalist predators that feed on nest eggs.

The researchers looked at the case of the willow ptarmigan in a mountainous area of south-central Norway, popular for vacation homes. They looked at a number of potential indicators of nest predation and found evidence that more eggs were lost to predators with closer distance to vacation homes.

Willow ptarmigan (Lagopus lagopus) in Norway. Credit, Per Harald Olsen.They also found evidence that the culprits were other birds  - known predators, hooded crows and ravens were more abundant closer to homes.

The researchers set up artificial nests with eggs from hens and found greater predation closer to houses. They also found that ptarmigan breeding success and the number of chicks was lower closer to homes even though the overall population density of the bird was the same.

These findings suggests that ptarmigan from outside immigrate into areas with greater housing where breeding success is lower. This sets off red flags that in some cases, rural housing could cause population sinks despite no detectable change in population numbers.

Of course this study only looks at one bird in Norway, and so this does not necessarily translate to other birds and other geographical areas.

However, the study adds to the growing evidence showing that low density housing in rural areas can have negative impacts on wildlife.

The sad irony is that the demand for these types of homes is likely driven by people who want to be closer to nature. Unfortunately, these houses may be bringing negative impacts closer to protected areas and other important places for wildlife. 

--by Rob Goldstein

Støen, O., Wegge, P., Heid, S., Hjeljord, O., & Nellemann, C. (2010). The effect of recreational homes on willow ptarmigan (Lagopus lagopus) in a mountain area of Norway European Journal of Wildlife Research DOI: 10.1007/s10344-010-0378-9