The View from Hawk Mountain: Highlights from the ASNV Day Trip with Dr. Tom Wood

Photo: Broad-winged Hawks, Matt Felperin

Tina Dudley

Hawk Mountain view, Sophie Bodrog

Fourteen participants met up at the Hawk Mountain Sanctuary Visitor Center on Saturday, September 18, 2022, to witness and learn about a migration hawk watch. The group was a lively mix of new and long-time ASNV members, including Nextgen members. Professor Tom Wood oriented everyone to what we would be seeing at the North Lookout. He explained what to look for and how to follow along with the hawk counters’ calls. He provided each participant with a helpful cheat sheet on what to look for in making an identification. He also explained how the weather could affect the number of hawks that might be on the move that day. Studies over time have shown that the number of migrants passing through can increase during the one to three days after a cold front.

The migration spectacle begins somewhat late in the morning, because ideal conditions occur when the sun heats the ground enough to cause rising currents of warm air. When warm air hits cooler air, the warm air rises up, forming thermals, which are like elevators to the hawks. When they catch one, they can soar up effortlessly, letting them then drift south from on high while they look for the next thermal. When the air is heating up in the morning the hawks circle one another, looking for a bird catching a thermal. A “kettle” forms when a number of hawks catch the same thermal, rising on the warm air in big circle.

The hike up was moderately challenging, but the view at the top was stunning. After we all got situated on various rocks, we were able to observe a distant kettle of Broad-winged Hawks. The photo of Broad-winged Hawks that accompanies this article is from a different hawk watch, but it’s a good image of what we were able to see. On a few occasions, a Broad-winged flew close enough to our lookout to give us a clear view of its distinctive black-and-white-banded tail and the dark border of its wings. 

While we were at the North Lookout in the morning, we saw 30-40 raptors along with some resident turkey vultures. As Nextgen member Sophie Bodrog described it, “[K]ettles of Broad-winged Hawks began to form in the haze on the horizon. The specks appeared and disappeared in the clouds as they were buoyed by currents of rising warm air. In mere minutes, the birds would be gliding overhead, heading for the next thermal” to continue their journey. All About Birds reports that Broad-winged Hawks migrate an average of 4,350 miles to northern South America to over-winter, averaging 69 miles each day. 

In addition to raptors, we saw an unsettling number of Spotted Lanternflies. We could see them in the air all across the valley in front of us. Dozens of them landed on us and skipped around the rocks we sat on. This invasive species can damage native plants, trees, and agricultural crops significantly. It has already been found in Loudoun County. Learn how to identify and combat this invader here. 

Most of the participants were on the road back to Northern Virginia when a large number of hawks passed through later in the afternoon. Although it was frustrating to miss them, participants who came down from North Lookout before the busy afternoon were treated to an entertaining live raptor show in the Sanctuary’s amphitheater. Volunteers showed off two of the raptors cared for at the facility, an American Kestrel and an Eastern Screech-Owl. None of the resident raptors can be released because of injuries or, in the case of the Kestrel, its imprinting on humans instead of its parents. 

Hawk Mountain Sanctuary was founded by Rosalie Edge in 1934 to combat the over-hunting of hawks on the Kittatinny Ridge. In the 85 years since its inception, Hawk Mountain has welcomed and educated thousands of visitors. Edge originally leased 1,400 acres for the Hawk Mountain Sanctuary Association, and it has since grown to 2,600 acres, with over 60,000 visitors per year and more than 9,000 members that keep the Sanctuary’s mission alive. The two Kestrel boxes ASNV is donating to encourage nesting birds at the Lorton Landfill come from the Sanctuary’s gift shop.

September Bird of the Month

Photo: Yellow-billed Cuckoo, Kelly Colganazar

Bird of the Month: Fall Migration Brings Cuckoos to Virginia

By Jessica Biggers

When you hear “ka-ka-ka-ka-ka-kow-kow-kowlp-kowlp-kowlp-kowlp” or a mellow “cu, cu, cu, cu” call in the distance it might be a sign of rain. Because of the Yellow-billed Cuckoo’s (Coccyzus americanus) and the Black-billed Cuckoo’s (Coccyzus erythropthalmus) weather forecasting abilities, they are commonly known as the “rain crow.” As a rain storm is blowing in, our little friends are giving us a heads up to run for cover. These elusive birds are rarely seen but heard, and their song and call can carry quite a distance. They are also long-distance migrants flying silently to their destination.

Sometimes Yellow-billed and Black-billed Cuckoos get a bad rap, being compared to their close cousin the Common Cuckoo from Eurasia. The Common Cuckoo is a brood parasite whose call is mimicked by a cuckoo clock’s chime. Although, Yellow-billed and Black-billed Cuckoos will occasionally lay their eggs in other birds’ nest, it is not a common occurrence. In most cases, if they do, they will lay their eggs in other cuckoo’s nests.

Even though both Yellow-billed and Black-billed Cuckoos can lay up to two broods, they tend to only raise one and don’t lay their eggs all at once, but asynchronously. Youngsters, when threatened, will make a display similar to a bittern, where they stretch their necks, with their heads looking straight up into the sky; standing like a statue.

Yellow-billed Cuckoos (YBCU) and Black-billed Cuckoos (BBCU) migrate through Virginia in the spring. But Black-billed Cuckoos breed farther north from Virginia while Yellow-billed Cuckoos have a more expansive breeding territory. In seasons when there is an abundance of caterpillars and cicadas, you’ll tend to hear and see more of them. YBCU’s have a preference for tent caterpillars, gypsy moths and cicadas, while BBCU munch on caterpillars of the spiny variety, shedding their stomach lining to remove the spines and coughing those spines up into owl-like pellets.

While our eastern Yellow-billed Cuckoo’s population is stable, the western population is struggling due to habitat loss. They inhabit woodlands, thick brush, marshes and abandoned farmland. Black-billed Cuckoos live more in woodlands and thickets.

This year, I’ve seen a ton of spiny and tent caterpillars, more than in past years. Plus, we’ve had a lot of rain. So, there is a good chance we’ll hear more of these elusive birds during fall migration as they head down to Mexico and Central American for the winter.

Sources:

https://web.stanford.edu/group/stanfordbirds/text/essays/Brood_Parasitism.html

https://www.audubon.org/birds-of-america/yellow-billed-cuckoo

August Bird of the Month

Photo: Red-shouldered Hawks, Linda Krueger

Bird of the Month: Who’s that Calling in the Air?

By Jessica Biggers

“Tier, Tier, Tier, Tier, Tier.” Have you heard this call? It’s the call of a Red-shouldered Hawk (Buteo lineatus), but it could be a Blue Jay you’re hearing. Even if you have a discerning ear, the calls can be indistinguishable. Although I’ve found that a Red-shouldered Hawk call tends to be longer, a bit sharper, higher pitched and louder than its copycat. 

There’s definitely a healthy population of resident Red-shouldered Hawks in Northern Virginia. Reston Association (RA) volunteers tallied 38 of them in Reston alone during this spring’s 24-hour bird survey. 

They are also one of the Audubon at Home program’s Sanctuary Species. Red-shouldered Hawks in our area tend to live in deciduous forests with little understory, enabling them to see better while hunting. Although, you will also find them in residential areas on the edge of forests. There was even a nesting pair who strayed farther away from the woods to make their home in a maintenance shed at the RA Central Services Facility (CSF) in Reston last spring. Most red-shouldered pairs return to the same nest from year to year, but unfortunately our CSF occupants did not come back this spring. 

If you do find a nest, take a look on the ground for bird poop, which is a good sign that it’s active. Red-shouldereds have one brood per year with a clutch of between two and five babies. Five days after the brood hatches, the babies start throwing their poop over the nest. Another earlier sign that you can look for is a nest decorated with pine boughs. You can often find some pine boughs on the ground near the nest.

During the breeding season, males do an elaborate aerial mating dance. They begin calling while soaring, and then make some steep dives towards the female. They fly back up in a spiral pattern before diving back down again to mate. Most Red-shouldered Hawks pair for life and usually hunt together year round.

These hawks are pretty easy to identify compared to their fellow hawk neighbors, like the Cooper’s Hawk. Their markings are distinguishable from the others; with their reddish-peach barred underside and a sharply defined banded tail. However, you are more likely to see them in flight than hiding out in a tree. 

So, the next time you hear a “Tier, Tier, Tier, Tier,” listen very closely and see if you can guess who it is – your friendly red-shouldered neighbor or one of those sneaky Blue Jay mimics. Happy birding!

Sources:

https://www.allaboutbirds.org/guide/Red-shouldered_Hawk/overview