NATURE NOTE – Number 76 September 14, 2023
Introduction:
Fall is almost here, and with it come some opportunities to see parts of nature not available during much of the rest of the year. We quickly think of the colorful leaves (see NATURE NOTE #6), squirrels gathering acorns for the winter (see NN #62), and many other activities brought about by the shorter days (see NN #16) and cooler weather. Something we have not discussed earlier is…
Our Current Topic: Hawk (Raptor) Migration
We discussed hawks in NN #5, but not their unique migration patterns that occur in the fall. This is a real treat for dedicated and casual birders as well. Along our nearby Blue Ridge Parkway, Afton Gap (where I-64 crosses the BR Parkway) and Harvey’s Knob overlook north of Roanoke (Milepost 95) are major observation points for observing this movement. Different species migrate at different times, but there is considerable overlap during September and October. At these locations we can see (given the correct weather conditions) large numbers of various species of hawks, eagles, and Osprey headed south for the winter from their breeding grounds to the north. They take advantage of the wind currents caused by rising heat from the Blue Ridge Mountains to soar for miles and at altitudes of up to 2000 feet along the crests of the Blue Ridge without a single wing beat. This unique action is referred to as “kettling”. Many of these birds are headed to South America, while others will stop somewhere in the southern U.S. As cold weather and snow sets in in their northern range, the small mammals, reptiles, amphibians, and insects that make up the diet of most raptors become difficult to find and moving south is their way of surviving. The younger birds are often the first to migrate. Let’s review the hawk species in our area; during migration and at other times.
Buteos (genus Buteo) are referred to as “broad-wing” hawks because of their wide wings. These are ones typically seen soaring and circling overhead (don’t confuse them with vultures; See NN # 5) sometimes in pairs, or larger groups during migration.
- The Broad-wing hawk (this is a specific species - Buteo platypterus - and not the grouping) is a small, crow sized bird that is a summer resident only. They are inclined to be in deep forests, but can be seen soaring and showing their banded tail as well. Its peak migration in our area is mid-September, and this hawk makes up by far the largest number migrating along the Blue Ridge.
- The large Red-tailed hawks are the most common in our area. They are year around residents and can be seen in the winter sitting on tree limbs and utility lines along highways. They are also a common sighting at Harvey’s Knob. A good field mark on a dark, stationary bird is the white breast with a dark band across the breast. Sometimes this band is subdued. In flight, the key mark is the fan-shaped rusty red tail that is almost translucent.
- The Red-shoulder hawk is also large, but mostly likely found in deeper woods and often along a steam. Seldom will they soar. Their tail has black and white bars across it, and, if you are lucky, you can see the red-shoulders. This bird is somewhat uncommon and does not migrate to any great degree.
- The Rough-legged hawk is an occasional winter visitor in western Virginia, depending on food supply in its northern Canada breeding grounds, and is not a significant part of the great fall migration. It is a large, long-winged Buteo with a single dark bar at the tip of its white tail. Often seen hovering.
Accipiters are the next group of hawks. There are two species likely to seen in this area, and both look very similar. The major difference is the size, but that is quite tricky as their size overlap and it’s hard to judge size accurately on a flying bird. Tail shape, which can be hard to see, helps in identification. The male and female have different color patterns. Check your field guide. Their peak migration period is from mid-September through October and they are common at Harvey’s Knob.
- The Sharped-shin hawk is the smaller pigeon-sized one, with a squared-off tail.
- The larger, crow size one is the Cooper’s hawk. The Cooper’s tail is rounded at the end.
- Goshawks are an unlikely, but possible, winter visitor.
Next are the sleek and fast falcons. The most common species here is the Kestrel, or Sparrow hawk. Small, dove-sized, the most likely spot for these speedsters is on a utility line bordering an open field. Their striking color pattern is a sure tell-tale sign. Peregrine falcons are making somewhat of a comeback in Virginia, and are seen occasionally in downtown locations (Richmond) nesting on a tall building ledge. While there are very limited reports of nesting in western Virginia, there are sightings of Peregrines at Harvey’s Knob. Both the Kestrel and Peregrine migrate in late September and into October although the overall numbers are usually small.
Finally is the Harrier. Similar to a Buteo, this species is most often seen flying low (4-8 feet) above a large grassy area, like an airport or marsh, searching for an exposed mouse or mole. The key mark here is the white rump and slightly uplifted wings. This species appears to be in decline in our area, but mid-September through October is its peak migration period.
Opportunity:
If you have the opportunity to visit Harvey’s knob or other known hawk watching point, you stand a good chance of seeing this migration in action. Use the internet for more info on Harvey’s Knob Hawk watching. In addition to some of the birds listed above, Bald and Golden eagles and Osprey are likely as well. Just be aware that watching any ridge line in western Virginia might reveal some of this migration in smaller numbers. Another good opportunity to show scouts some nature at work. If you can’t make the trip, watch for media coverage on this migration and share that with your scouts. Hawks, although often seen in suburban areas, seem to provide a sense of “the wild” that is still out there. Being at the top of the food chain, they also exhibit certain supremacy in the animal kingdom as they soar over their domain or view it from a lofty perch. Enjoy them.
As always, thank you visiting NATURE NOTES. Please forward any thoughts to me at
Bob Garst
