September 3rd , 2013 9:24 am Leave a comment

Vultures serve as nature’s sanitation crews

By

If you’re like me, the arrival of September has almost taken you by complete surprise. Where did the summer go? Of course, the official first day of fall doesn’t occur until Sept. 22, but birds don’t read calendars. For birds from hawks to warblers to tanagers and terns, fall migration is already well underway.

Photo by Bryan StevensA Black Vulture and two Turkey Vultures.

Photo by Bryan Stevens
A Black Vulture and two Turkey Vultures.

I am sure that I will see a lot of birds this month as more migrants begin traveling through the region on their way to wintering grounds much farther south than Northeast Tennessee.
I haven’t found any new species to add to my year list this past week, but it’s not been for lack of trying. I spent some time on Aug. 25 birding around Austin Springs on Boone Lake, although most of the activity on the lake was caused by people instead of birds. I did find some Great Blue Herons, Belted Kingfishers, Canada Geese, Wood Ducks, Mallards and a soaring Broad-winged Hawk.

In a recently mown field on Hyder Hill Road, I also found a flock of vultures. Some members of the flock were searching the field while others focused on finishing off some road-kill. I suspect a lot of people don’t pay much attention to the vultures. Often, we see them from a distance as they soar overhead on warm thermals of air rising from the ground.
The United States is home to three species of New World vultures, a family that is distinct from the Old World vultures of Africa, Asia and Europe. The New World vultures consist of seven species — including two condors — found in North and South America. The Old World vultures consist of 16 species.
Two vultures — Turkey Vulture and Black Vulture — can be found in the region throughout the year.
When on the ground, Turkey Vultures could be mistaken for Wild Turkeys due to their size and brown coloration. From a distance, these vultures appear black, but on closer inspection their feathers are definitely dark brown. Turkey Vultures, except for young birds, also have bare red heads. The Turkey Vulture boasts a six-foot wingspan and can weigh as much as five pounds.
The aptly named Black Vulture has black plumage, as well as a black head. The Black Vulture is a fairly large bird of prey. This vulture’s wingspan can reach 66 inches. Large specimens can reach a weight of six pounds.
The Turkey Vulture is the most widespread of the New World vultures and ranges from southern Canada to the southern tip of South America. The Black Vulture also ranges widely and can be found through the southeastern United States, Mexico, Central America and much of South America.
The Black Vulture is considered a more aggressive bird than the Turkey Vulture. While both birds are primarily scavengers, the Black Vulture will also attack young, vulnerable or ill creatures, including cattle and other livestock. The two species will often share roosting trees, but they compete for carrion.
Because of their lot in life as scavengers, vultures probably don’t enjoy a stellar reputation. But they’re a necessary part of the ecosystem and perform a vital service. Just consider them nature’s sanitation crews.
The most famous of the New World vultures is probably the endangered California Condor. A conservation plan was put in place by the federal government that led to the capture of all 22 remaining wild condors in 1987. These surviving birds were bred at different California zoos. Their numbers rose through captive breeding and, beginning in 1991, condors were reintroduced into the wild.
The effort has been a tentative success, although the California Condor remains one of the world’s rarest bird species. A count conducted in May of 2012 found 405 individuals, including 226 living in the wild and 179 in captivity.
The California Condor has an impressive ten-foot wingspan. The condor bests such birds as Trumpeter Swan and American White Pelican for biggest wingspan of any North American bird. A few species, however, weigh more and have a longer body length. The Andean Condor of South America boasts a heavier body weight and a wider wingspan than the California Condor.
The California Condor is an example of what a good job we can do in protecting wildlife when we really devote ourselves to the effort. The population remains endangered, but visitors to certain locations in California and Arizona can still see these birds flying free in the wild. It’s an achievement worth celebrating.
•••••
While staying at The Haven at Knob Creek apartment complex this past week — I’m caring for my brother’s dog — I saw several Common Nighthawks swooping very low to the ground over adjacent fields. It was fun to get to see these medium-sized aerobatic birds foraging at such close range.
Although I am still seeing these migrating nighthawks, I read about an alarming population trend thanks to a post on Bristol-Birds this past week.
Local birder David Kirschke reported that the May/June 2013 issue of Birding magazine features an article on Common Nighthawk population declines, which are described as drastic. He wondered if people are seeing such a trend in the region.
Rick Knight, who has been compiling records for four decades for the Lee and Lois Herndon Chapter of the Tennessee Ornithological Society, responded to David’s query.
“I would estimate that nighthawk populations are down by 70 to 80 percent from what they were just 20 to 25 years ago,” Rick wrote in his post. “That figure covers local breeders and migrants.”
I can also remember that when I began birding, I would see flocks of hundreds of nighthawks in the fall. In recent years, I have seen flocks consisting of dozens of birds.
Reasons for this decline are not entirely clear. Some factors contributing to this decline would probably include habitat loss, pesticide use and a switch from gravel roofs to rubber roofs in many urban areas.
•••••
There are plenty of birds moving through the region. Get outdoors in your yard or your favorite park and see what you can find. To share a sighting, ask a question or make a comment, call me at 297-9077 or 542-4151 or send email to bstevens@starhq.com or ahoodedwarbler@aol.com.

Comments

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>

share Facebook Twitter

Switch to our mobile site