Background
The authors write -- and, sad to say, quite correctly -- that "researchers have typically assumed that if climate change affects amphibian species, the outcome will be negative," and they note, in this regard, that "rarely do we allow ourselves to consider that global warming may confer benefits to some species." Fortunately, they were able to break out of this thought-confining view of the subject and look at things more realistically.

What was done
In a nine-year study conducted in the Little Rock Creek Basin -- located within the Selway-Bitterroot Wilderness just south of Hamilton, Montana (USA) -- McCaffery and Maxell "evaluated relationships among local climate variables, annual survival and fecundity, and population growth rates" in "a high-elevation population of a temperate pond-breeding frog species, the Columbia spotted frog (Rana luteiventris)," monitoring all life stages of the species and relating the demographic data thereby obtained to climate data collected at a nearby weather station.

What was learned
The two University of Montana biologists report discovering that "parameters that describe winter severity were negatively correlated with survival, transition, and breeding probabilities in this high-elevation R. luteiventris population," and that there was "an increase in survival and breeding probability as severity of winter decreased."

What it means
"Contrary to much of what has been discussed in the literature," in the words of McCaffery and Maxell, "these results suggest that under certain circumstances, a warming climate may be helpful to some amphibian populations, particularly those that live in harsh conditions at the edge of their thermal tolerances." As a case in point, they write that their results "unambiguously demonstrate that earlier ending winters with lower snowpack in this system lead to higher survival rates, higher probabilities of breeding, and higher population viability." Thus, they conclude that "more generally, amphibians and other ectotherms inhabiting alpine or boreal habitats at or near their thermal ecological limits may benefit from the milder winters provided by a warming climate."