Polar Bear News: the Emergence of Noise Pollution as a Threat and a Climate Change Denier Smackdown
Two interesting polar bear items caught my attention this week.
First, last night BBC’s Science in Action had a fascinating piece on tests of polar bear hearing thresholds (that is, what is the spectrum of sound that polar bears can actually detect?) being conducted in San Diego. This work is more significant than it may appear because several studies suggest that noise pollution can have a negative effect on polar bear behavior (particularly denning behavior). And oil exploration and development? Well, it ain’t quiet. NRDC flagged this potential last year, in a letter to the U.S. Fish and Wildlife Service:
Noise disturbance from seismic activities of oil exploration as well as ground and air transportation can be heard within 300 meters of dens…Exposure to noise from drilling and vehicles may cause bears to abandon their dens In other circumstances, den disturbance has been linked to lower birth weight in female cubs.
As one of the scientists in the Science in Action story says:
Noise is a potential problem and it has been in their environment for decades now. The combination of noise disturbance on top of the implications of climate change for polar bears are the problem. Noise in and of itself is not a problem for polar bears, but if you layer it on top of the impacts of climate change, then you have the potential for a real problem.
Second, two of the world’s foremost polar bear researchers, Ian Stirling and Andrew Derocher, just published a world-class smackdown of an article that appeared in Ecological Complexity last year suggesting that polar bears in the Western Hudson Bay weren’t threatened by global warming and, even if they were, could adapt. The whole thing is worth checking out, but this bit (responding to the suggestion that polar bears can compensate to the decline of seals in the Arctic by eating more vegetation) was my favorite:
Polar bears are large animals that, similar to their brown bear relatives, require energy dense foods in the form of fat and protein, to maintain body size and population densities (Hilderbrand et al., 1999; Felicetti et al., 2003). They got that way be eating seals, not berries. (Robbins et al., 2007).