A week ago today, I noticed a Turkey Vulture soaring over the Hill Country and realized that I had failed to mention these birds in my article about the start of spring migration. Many of you likely were unaware that they had left our region, so what is so important about seeing a Turkey Vulture on February 20 near Stonewall, Texas? For reasons not fully understood, these birds depart the Hill Country and head south in December and do not return until the last week in February. Unlike Swainson’s Hawks, who fly eight or nine thousand miles south to their winter home in Argentina, Turkey Vultures can be found only a hundred miles away in the San Antonio or Austin areas in the winter.
However, the short distance may be misleading because these vultures may have traveled from Canada to reach the Hill Country before they leave for San Antonio. All we know for sure is that Turkey Vultures are common in the Hill Country from March to December. Where these birds spent last summer is unknown – it might have been anywhere between the Hill Country and Canada. Without tags or radio transmitters we cannot confirm where they have been or where they are going during migration. We only know the beginning and end locations of numbers of birds, not individuals.
During a trip to San Antonio or Austin in the winter months, you will likely observe Turkey Vultures soaring over the countryside, or even the cities. Christmas Bird Counts in our area rarely find Turkey Vultures. All migratory birds have summer and winter ranges that can be mapped and documented with surveys. The northern edge of the Turkey Vulture’s winter range is just south of the Edwards Plateau, and more specifically, the Hill Country.
Because of the slightly higher elevation here in the Hill Country, the average daily temperature may vary around ten degrees between Kerrville and San Antonio. Ten degrees might not seem important to those of us who live here all year, but it obviously matters to the Turkey Vultures. As these carrion-eating cannot eat if their food source is frozen, they must live where their food source is not frozen for a period of time more than a day or two.
If you have lived in the Hill Country for some time, you are aware that we have cold spells occasionally that last for several days at or below freezing. A Turkey Vulture will have survival issues if all of his food is frozen. We also have many Black Vultures that winter in the Hill Country; how can they survive longer periods of time when their food source is also frozen? Apparently Black Vultures have stronger muscles controlling their beaks than do Turkey Vultures. Black Vultures may have the strength to be able to feed on partially frozen carrion.
How does one differentiate between Turkey and Black Vulture? Turkey Vultures have longer wings and tails than do blacks; thus the Turkey Vulture can soar for longer periods of time than blacks can. Black Vultures have shorter wings and tails that require them flap their wings more often to remain in the air, thereby using a technique of “flap and glide” to stay airborne. Mature Turkey Vultures have red naked heads, while blacks have black naked heads. Black Vultures also have white wing patches.
Turkey Vultures have several nature festivals named in their honor, the largest being in Hinckley, Ohio in mid-March. Apparently they are very punctual in their travel schedules. Even though they are also fairly consistent in their annual return to the Hill Country, we are not going to call out the bands to welcome them back. They seem quite happy to sneak back with no fanfare. Nevertheless we are very pleased to have them on the job helping the Black Vultures clean up the carrion on our roads. I remind you that while they are not pretty birds, they are pretty important to us for the jobs they do.