What was done
The authors studied the responses of a small passerine songbird of southern Norway - Cinclus cinclus - to variations in mean winter temperature and total winter precipitation over a period of twenty years.  After developing a model based on their observations, they determined the response of the birds to a 2.5°C increase in air temperature, such as is predicted to occur by several climate models in response to a doubling of the air's CO2 concentration.

What was learned
The 2.5°C increase in air temperature increased the expected Cinclus cinclus population of the region studied by 58%.

What it means
Another one of those catastrophic consequences of dreaded global warming: more melodious warbling for southern Norway!