Turkey Vulture On A Very Hot Summer Morning
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Late June and early July are the hottest part of the summer in southern Arizona. The annual (hopefully!) monsoon rains haven’t yet arrived. It is common on those pre-monsoon days for the high temperature to reach or exceed 110 degrees Fahrenheit (more than 43 degrees Celsius). It was a Sunday morning a couple of weeks ago on what would turn out to be one of the year’s hottest days that Louisa and I found ourselves cruising a back road in the hamlet of Three Points, about 30 miles southwest of Tucson. Three Points lies in a large valley and it can really cook on a hot summer day. On that occasion the temperatures were already well into the 90’s at 6:30 in the morning.
That’s when we encountered this Turkey Vulture, relaxing on a dead tree.
The vulture was perched close to the road and it clearly saw us stop to observe it. It showed no interest in flying, notwithstanding our presence close by. Clearly, it had decided that conserving energy was more important than avoiding our prying eyes.
As we watched, the vulture lazily scratched an itch.
It continued to sit on its perch and after a while we drove off with it still sitting there.
In our environment wildlife has evolved all sorts of strategies for staying cool on hot days. Vultures have perfected two strategies. First, they are world champion soarers. These birds can spend hours riding thermal air currents rising from the superheated desert without expending any meaningful energy. They simply spread their huge wings and float effortlessly on the rising air, sort of like one of us lying on an air mattress in a swimming pool. They utilize that strategy to soar to an altitude, sometimes thousands of feet above the desert floor, where the air temperature is significantly cooler than the desert below.
Their second strategy may seem a bit weird, but it works for the vultures. They pee on their legs. On a blazing hot day the urine evaporates very quickly, and as it does, it transfers heat from the blood vessels in the vultures’ legs to the surrounding air. You’ll notice that areas on this this vulture’s legs are a chalky white in color. In fact, the vulture’s skin is bright pink. The white consists of deposits of salts left over from the evaporated urine.
So, one can say with a straight face that Turkey Vultures are pretty cool birds — even on the hottest of days!
Images made with a Canon 5Div, 400mm f4 DO II lens+1.4x telextender, M setting (auto ISO), ISO 1250, f7.1 @ 1/2000.