Raptors are certainly not a popular bird species, but Dr. Gregory Grove, a professor at Pennsylvania State University, spearheads a Winter Raptor Survey across Pennsylvania from mid-January to mid- February.

A birder for over 25 years, Dr. Grove’s interest in hawk watching developed by observing fall migrations at Hawk Mountain. “I wondered about the intervening winter period and how many raptors winter in Pennsylvania, how they are distributed over various parts of the state in winter, and over many years, would we detect any population trends,” he said.

In 1991, he initiated the first fall count of raptors on Stone Mountain, located on the Huntingdon-Mifflin county line. Today, the annual WRS now extends throughout Pennsylvania and is held in mid-January to mid February.

Working with the members of the Pennsylvania Society for Ornithology, there are 150 WRS routes statewide conducted in almost every county. “The total combined coverage by all participants is, on the average, 500 hours each winter. An average of 8,000 miles of road are surveyed,” Dr. Grove explained.

He compiles the data that is forwarded to him.

“I then write a summary which is published in “Pennsylvania Birds”, the journal published four times a year by PSO.”

The most common raptor in the state appears to be red-tailed hawks. “They are certainly the most obvious because of their large size and preference for open areas when they can be seen more easily,” he said from both personal observations and collected data.

According to Dr. Grove, they are easily identified by a brown band of belly feathers across a light colored front. “This is a very useful feature used by birders to identify red-tails, when the tail is not visible,” he explained. “It is only adult birds which have the red tail; juveniles have a brown tail.’’

There are two species of raptors that winter in Pennsylvania — the golden eagle and rough-legged hawk. “These are somewhat rare, but they breed north of Pennsylvania and come this far south only in winter,” he said.

Actually, there are 12 species of raptors that can be observed during winter. “Kestrels are our smallest raptor,” Dr. Grove commented.

“They are seen perching on utility lines, from which they scan for mice, or small birds like sparrows. The males are a combination of blue, red and gray. Females are brownish.”

Another species is the northern harrier. “These hawks are brown or gray and are often seen flying low and slowly over grassy fields. They hold their wings somewhat upward, in a shallow ‘V’,” he said giving the identifying features.

It is usually the small long-tailed sharp-shinned hawk (robin size) and the Cooper’s hawk (small crow size) which are the culprits that swoop down on unsuspecting songbirds at backyard feeders. “They prey mostly on birds,” he said.

Aside from recording data on population trends, there is another reason why the WRS is important. “It helps identify areas of the state that are most important to wintering raptors. The answer is actually rather clear — the central and south-central counties within the drainage area of the lower Susquehanna and Juniata Rivers hold the largest numbers of wintering raptors. This is probably because of a combination of lots of agricultural lands, but not excessive development, and also the milder climate compared to northern and western part of the state,” Dr. Grove explained.

“I think the public understands much more (about hawks) than they did 50 or 100 years ago, when such birds were considered pests, to be shot or poisoned. However, a concept that is not fully appreciated and understood by much of the public is how all forms of life are truly interconnected. If one part of the food chain is altered, the effects will eventually resonate in unpredictable ways through all parts of nature’s food webs,” he said.