More research to prove that global warming is shrinking tasty animals has appeared this week.

First up: extra on the Soay Sheep in Scotland. Earlier this month a paper in Science suggested that these animals were shrinking in size due, at least in part, to climate change (see: Scotland’s shrinking sheep shocker – July 03, 2009).

Now a new paper in Biology Letters comments on the fact that the larger sheep also tend to have darker coats than the smaller sheep. There is, say Shane Maloney, of the University of Western Australia, and colleagues, apparently a genetic link between coat colour and body size.

This may be another reason for the decline of the larger, black sheep: “While in the past a dark coat has offset the metabolic costs of thermoregulation by absorbing solar radiation, the selective advantage of a dark coat may be waning as the climate warms in the North Atlantic,” the researchers write.

So as things get warmer there is less advantage in having a black coat to help you keep warm. With huge predictability, this news is being headlined “Bye, Bye Black Sheep” (AFP, Daily Telegraph).

Of course this could also be another example of a climate feedback loop. More white sheep will reflect more sunlight thereby cooling the planet (possibly).

In other news, a paper in PNAS suggests that climate change may also be causing fish to shrink. Martin Daufresne, of the Leibniz Institute of Marine Sciences in Kiel, Germany, and colleagues performed a meta-analysis of the effect of climate change on body size of a whole host of aquatic organisms, from fish down to bacteria.

They find a “a significant increase in the proportion of small-sized species” and show that as well as shifting species northwards climate change will make them small.

If you’re worried about the shrinking size of possible dinner animals though, don’t worry too much. Another study by Maloney provides another possible regulatory mechanism. Using 10 years of meteorological data for Perth he has previously calculated that global warming may make it harder to do exercise in 2030 and 2070, meaning we’ll need smaller meals.

“Our results provide evidence that whereas there are presently 3 or 4 days a year when outdoor activity is compromised by heat load, there will be up to 30 days per year if the predictions of CSIRO about likely temperature increases are accurate,” he notes on his webpage.

Image: detail from photo of sheep (not Soay) by John Haslam/ foxypar4 under Creative Commons via Flickr.