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Vulture Venture—

For folks in the midcoast region, sightings of soaring turkey vultures are a common sight, but that was not always the case. When ornithologist Ralph Palmer published his “Maine Birds” in 1949, he cited only 12 state records over the period of 1862 to 1944. In the intervening 70 years, things have changed dramatically across New England. The species was eventually confirmed as a Maine breeder on Camden’s Bald Mountain about 40 years ago. Do vultures currently nest around Knox County?

During the 2018 inaugural phase of the 5-year Maine Bird Atlas project, I strove to answer that question without full success. Observing scads of vultures in the sky does not directly translate into confirmed nesting status though. My fascination with vultures is not new. Scientific experiments revealed that vultures possess an extraordinary sense of smell in locating carrion. Perhaps more surprisingly, they are somewhat discriminating in their dietary choices, showing a preference for defunct herbivores over carnivores. So a road-killed deer carcass would rate higher on the vulture menu than a dead cat or coyote. And, contrary to popular misperceptions, fresher is better.

In a parallel scientific quest of my own design, I’d once tried to persuade my wife to recline (just briefly, mind you) in a grassy field where I might capture photos of vultures circling overhead. Her muttered response was definitely less than scientific. Later that summer, I encountered a successful vulture pair that had produced two fledglings amidst a collapsing summer cottage in Owls Head.

Last week I ventured into a stand of mature red oak and pine woods in Warren where numbers of vultures routinely perch during summer. Would I find any evidence of breeding activity there? Unlike osprey and eagles, who have high-profile tree nests, vultures are more secretive in selecting nest sites. Concealment from animal predators is a real concern, since the young are fed on carrion that could emit strong telltale odors. There is little or no actual nest building involved. Preferred sites include precipitous cliffs, caves, hollow stumps and logs and dense shrubbery. For these reasons, detection of nests is understandably low.

The sun-dappled forest floor in Warren was thoroughly whitewashed with excrement. Dozens of molted wing and body feathers scattered the ground. Adult vultures gradually molt a portion of feathers throughout the summer while supplies of carrion are most readily available. As I explored the grove, one sizeable ground cavity beneath a huge downed oak trunk drew my attention, but was not utilized for nesting. This site bears watching during next year’s nesting cycle.

With their featherless reddish head and heavy bill, vultures are eminently equipped to perform Nature’s essential cleanup tasks. I believe vultures get an undeserved rap as disgusting filthy creatures, capable of spreading disease. Actually, the reverse is true: with their impressive immune system and cast-iron stomach, they gobble up germs that would likely kill humans. By removing large amounts of decaying meat from the environment, vultures reduce contamination of air and groundwater. For example, vulture stomach acid can effectively process and sterilize botulism toxins and anthrax spores without ill effects to the bird. It is well documented that vultures habitually defecate on their own legs. Why would they perform this unsavory behavior, you ask? One likely benefit is to cool their legs in extreme hot weather (birds can’t sweat.) Secondly, the birds are disinfecting their own legs after contact with bacteria-laden carcasses. Amazing but true, vulture excrement is totally sterile!

Soon enough, numbers of gray-headed juvenile vultures will join adults at fall roosts before heading southward for the winter. For now, I’m left to wonder if they were reared somewhere within the Warren ZIP code area?