Saturday, 5 February 2011

Verdin on a windy day

It was a very windy day in Edinburgh today - glad I wasn't out birding to be honest. But I did think back to the unseasonally strong winds that hampered my birding during our stay in Joshua Tree National Park, California, in April. This Verdin, a desert-adapted penduline tit, was sheltering in typical thorny bush habitat in the lee of a vast oil drum. In a bizarre quirk of fate, it turns out that this species is one that has had its physiological response to wind speed closely monitored in metabolic chamber wind tunnel tests! The results when extrapolated to birds in their natural environment indicate that moderate increases in wind speed are predicted to increase metabolic demands by 20-30% above normal requirements. Given the wind speed, I think that the figure might have been even higher on the day I took this photo.

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