Category Archives: Birds of Prey

Bald Eagle Or Golden?

Juvenile bald eagle near the Harmar Twp nest, 1 July 2018 (photo by Annette Devinney)
First year juvenile bald eagle near the Harmar Twp nest, July 2018 (photo by Annette Devinney)

Young bald eagles can be hard to identify because they don’t have white heads and tails. To complicate matters, our field guides show a very similar bird, the golden eagle. How can you tell if a large dark bird in western Pennsylvania is a bald eagle? Here are some tips, plus a comparison to golden eagles.

First, make sure the bird is not a turkey vulture. See V Is For Vulture for details.

Second, the location, time of year, and habitat are your best clues to its identity.

  • Location and time of year:
    • Bald eagles are year round residents of Pennsylvania. Their population is booming.
    • Golden eagles are rare in eastern North America and only seen at Pennsylvania hawk watches during fall and spring migration.
  • Habitat:
    • Bald eagles eat fish and are found at rivers and lakes. They are tolerant of human settlements and will nest in suburbs or towns near water.
    • Golden eagles eat meat and are found in open country such as mountains, cliffs, tundra, grassland and deserts. They avoid human settlements.

Third, you’re ready to look at plumage with this caveat: I am not an expert at aging immature bald eagles. If you have tips, photos or corrections please leave a comment.

BALD EAGLE FIRST YEAR PLUMAGE: (“first year” and “juvenile” are synonymous)

In their first year of life juvenile bald eagles have dark gray beaks, dark brown feathers overall with variable white mottling under their wings and tails. The photo at top by Annette Devinney shows the white mottling seen in flight.

Hays juvenile bald eagles before they fledged, June 2014 (photo from that Hays Bald Eaglecam)
Hays juvenile bald eagle, H8, June 2018 (photo by Annette Devinney)
Harmar’s juvenile bald eagles playing in the sky, July 2018 (photo by Annette Devinney)

SECOND AND THIRD YEAR PLUMAGE: (called “immature” birds)

In their second year bald eagles turn whiter with additional mottling on their backs, bellies and wings. Still mottled in their third year, their bodies darken while their heads and tails turn whiter.

Second year birds may show uneven trailing edges on their wings because first-year flight feathers are longer than those of older birds. This bird shows a mix of old and new feathers.

Immature bald eagle, second year (photo by Steve Gosser)
Immature bald eagle (photo by Steve Gosser)

FOURTH YEAR PLUMAGE: (nearly “adult,” may nest at four years old)

Bald eagles complete their adult plumage in their fourth year. Their heads and tails have a slightly dirty appearance due to a few dark feathers. In 2013 the new Harmar female had some dark tail feathers, below. She was probably only four years old.

Harmar bald eagle, 2013 (photo by Steve Gosser)

FULL ADULT PLUMAGE: (fifth year and beyond)

Adult bald eagles with white heads and tails cannot be mistaken for any other North American bird. In the photo below, the Hays female carries a fish to her young.

Mother bald eagle carries a fish, apparently to entice H7 (photo by Annette Devinney)
Mother bald eagle carries a fish to H7 at Hays, 2017 (photo by Annette Devinney)


Juvenile bald eagles resemble golden eagles in size and coloration. However …

Golden eagles are dark brown with golden feathers on the nape of the neck. Adults have completely dark underwings and tails. Immatures have a white band at the base of the tail and dark underwings, not mottled, with either a white line down the middle of the wing or a white half moon at the wrist (see below). Golden eagles’ heads look smaller than bald eagles’ because their beaks are smaller. Here are two photos of golden eagles in flight at the Allegheny Front by Steve Gosser.

Golden eagles at the Allegheny Front (photos by Steve Gosser)

Finally, golden eagles are extremely rare in Allegheny County, even as flyovers, while bald eagles are resident year round if the rivers don’t freeze. An all-dark eagle near Pittsburgh is most likely a juvenile bald eagle. It may have been born here.

Learn more about aging bald eagles and comparing them to goldens at these links:

(photos by Annette Devinney, Steve Gosser and the Hays Bald Eaglecam)

White Barn Owls Stun In Moonlight

Barn owl, Scotland (photo from Wikimedia Commons)

Most owl species have camouflage-colored bellies, but most barn owls (Tyto alba) do not. Though their backs blend into their surroundings, the majority have brilliant white faces, bellies, underwings and legs. The rest are better camouflaged in rusty red, below.

Barn owl with reddish belly (photo from Wikimedia Commons)

The white color stands out in moonlight but is this visibility a disadvantage? Does the white owl’s prey see it coming and escape? Are reddish owls more successful on moonlit nights? Researchers ran tests to find out.

Barn owl watching for prey (photo from Wikimedia Commons)

In a barn owl study in Switzerland, scientists have been tracking plumage, prey availability, moon phases and breeding success for over 20 years. When they correlated moon phase with hunting success, they found that reddish barn owls have lower success on full moon nights than white ones.

This seemed very odd so they set up an experiment with full moon lighting and two taxidermied owls posed in flight — one white, one reddish. When a vole was placed in the “moonlit” room and presented with a flying (stuffed) owl, it froze in place for an extra 5 seconds when it saw the white one. Those 5 seconds were just enough time for the white owl to pounce. The reddish owl was out of luck. Apparently the glowing white plumage has its advantages.

White barn owls are stunning in moonlight.

Barn owl in flight, glowing white (photo from Wikimedia Commons)

Read more at “Moonlight Helps White Barn Owls Stun Their Prey” in Smithsonian Magazine.

(photos from Wikimedia Commons; click on the captions to see the originals)

From Broad Wings to Red Tails

Broad-winged hawk on migration (photo from Wikimedia Commons)

15 September 2019:

You can tell what month it is at a Pennsylvania hawk watch by noticing the most abundant raptor.

If you’re seeing a lot of broad-winged hawks, it must be September. Broad-wing migration peaks right now; they’ll be gone by the end of the month.

If you’re seeing a lot of turkey vultures and red-tailed hawks it must be October. In the fall of 2018, 90% of the turkey vultures that passed the Allegheny Front Hawk Watch went by in October.

Turkey vulture in flight (photo from Wikimedia Commons)

Red-tailed hawks spread their migration over several months. Last year at the Allegheny Front roughly 25% were seen in September, 50% in October, 25% in November.

Red-tailed hawk at the Allegheny Front, 31 October 2016 (photo by Steve Gosser)

If golden eagles are at their most abundant, it must be mid-October to mid-November. It’s my favorite time of year at the Allegheny Front.

Golden eagle at the Allegheny Front, 2 Nov 2016 (photo by Steve Gosser)

Pennsylvania hawk watches are about to switch from broad-wings to red-tails. Count the raptors to find out what month it is. 😉

(Broad-winged hawk and turkey vulture photos from Wikimedia Commons; click on the caption to see the originals. Red-tailed hawk and golden eagle by Steve Gosser)

Broad-winged Migration

Broad-winged hawk at Bent of the River, Connecticut, Sept 2016 (photo from Wikimedia Commons)

Every year, beginning in late August, broad-winged hawks (Buteo platypterus) head south on a 4,500 mile journey from their nesting territories in North America to their winter grounds in Central and South America.  It’s a journey many of us witness at Pennsylvania hawk watches. 

Unlike other hawks, broad-wings usually travel together. Though not in organized flocks they cue off each other to find the best travel conditions. This brings them together on migration.

The Allegheny Front Hawk Watch, 1.5 hours from Pittsburgh, saw 119 broad-winged hawks last Saturday but will peak September 13-15 with close to 2,000. Other Pennsylvania hawk watches will count even more.

Visit to see the latest statistics and find a hawk watch near you. Plan a visit soon.

Broad-winged hawk on migration, Bentsen Rio-Grande, March 2018 (photo by Bettina Arrigoni via Wikimedia Commons)

Meanwhile, keep looking up. There’s a good chance you’ll see a broad-winged hawk overhead in the next couple of weeks.

(photos from Wikimedia Commons; click on the captions to see the originals)

That Would Be My Perfect Flight

Falconry birds aren’t pets, they’re partners.

In this short film, Shawn Hayes describes his relationship with birds and how he became a falconer. His co-star in the film is an immature prairie falcon (Falco mexicanus) that he’s working with to orchestrate the perfect flight.

About the bird’s future he says:

The day that I release my bird back out to the wild I know that bird is going to survive. I know that bird is going to go out and probably get a mate and produce other birds in the wild. And I was part of that.

Shawn Hayes, “How One City Man Found His Calling in the Wild”

“Falconry is not a sport, it’s not an art — it’s a way of life.”

(video by Joshua Izenberg on the National Geographic YouTube channel)

Happy Fourth Of July 2019

Juvenile eagles H9 and H10 at Hays Woods, 30 June 2019 (photo by Dana Nesiti, Eagles of Hays PA on Facebook)

News from Hays Woods in Pittsburgh, PA:

This week the young bald eagles, H9 and H10, turned 100 days old. Dana Nesiti captured their antics on Sunday June 30 in the photo above and a slow motion video below.

Visit Dana’s Eagles of Hays PA Facebook page for more news, photos and videos of the Hays bald eagles.

Happy Fourth of July!

By the way, Pennsylvania now has so many bald eagle nests that the PA Game Commission can’t count them without your help. See Mary Ann Thomas’ TribLive article here.

(photo and video by Dana Nesiti, Eagles of Hays PA on Facebook)

Graceful Predator

Long-tailed jaegar in flight (photo by Gregory “Slobirdr” Smith, Creative Commons license on Flickr)

If I had to pick a Best Bird on my trip to Alaska it would be the long-tailed jaegar (long-tailed skua, Stercorarius longicaudus), the most graceful arctic predator.

Long-tailed jaegars are the smallest of skuas, a genus of predatory seabirds that range from pole to pole. In flight their long tails and flowing movements remind me of swallow-tailed kites as they float over the tundra in pairs and loudly defend their territories. On the hunt they can hover like kestrels, as shown in the video below.

Though long-tailed jaegars are seabirds, their favorite foods in Alaska are collared lemmings.

Illustrations of Nelson’s collared lemming and Ungava collared lemming at burrow (from Wikimedia Commons)

How does a seabird without talons capture rodents? Well, he doesn’t use his feet.

Long-tailed skua calling (photo by Allan Hopkins, Creative Commons license on Flickr)

Birds of North America Online explains his hunting technique …

Long-tailed Jaeger hunts these lemmings by hovering or poising in a headwind at height of 1-10 m [3-30 feet] (usually about 4 m) above tundra, like a kestrel unlike other jaegers, and by watching from perches on small rises or frost mounds … Having detected prey, often pursues it on foot and pecks it until it is dead; never uses feet to capture prey.

Birds of North America Online

Though both sexes can incubate, the male long-tailed jaegar spends two thirds of his time hunting for his mate while she warms the eggs.

Long-tailed jaegar on nest (photo from Wikimedia Commons)

We could see her white chest far away on the tundra, waiting for her graceful mate to come home.

(photos by Gregory “Slobirdr” Smith, Allan Hopkins and from Wikimedia Commons. Click on the captions to see the originals.)

p.s. Click here to hear the long-tailed jaegar’s call.

Not Always White

Gyrfalcon in upstate New York, January 2018 (photo by Tim Lenz via Flickr, Creative Commons license)

Alaska Birding with PIB: Nome to Anchorage 23 June 2019

Most people never see a wild gyrfalcon (Falco rusticolus), the world’s largest falcon and most northern diurnal raptor. Though gyrfalcons have a circumpolar distribution through North America, Greenland, Iceland and Eurasia, they rarely come south, even in winter. Their remoteness protected them from the past persecution of raptors and made them prized as falconers’ birds.

Compared to peregrine falcons, gyrfalcons have larger heads, thicker necks, bulkier deep chests, shorter and broader wings, and a longer tail. Gyrfalcons look like powerful prize fighters, peregrines are sleek and fast.

Gyrfalcons need this bulk because their prey items are much larger birds than peregrines eat. Gyrfalcons can kill cranes and Canada geese but their primary prey are ptarmigans, especially rock ptarmigans. In some regions the gyrfalcon population is cyclic in response to the ptarmigan population. Climate change is affecting the ptarmigan population — bad news for gyrfalcons.

We think of gyrs as white falcons because that’s what we see in the media but there’s a lot of color variation. Many are brown-speckled, like the bird in Iceland on the right.

Gyrfalcon color phases: a white falconer’s bird, a brown-speckled bird in Iceland (photos from Wikimedia Commons)

Most gyrfalcons in North America are a uniform dark brown, like this one that spent the winter of 2001-2002 at the Black Falcon Terminal (dock) in Boston, Massachusetts. This bird was so famous and so reliably found that 17 years later there are still photos of it online. Glen Tepke took this picture on 16 February 2002.

I mention this individual bird because I traveled to see it — the only gyrfalcon I’d ever seen until my trip to Alaska. It shows how rare they are in the eastern U.S.

Gyrfalcons live in Alaska year round and breed here in early summer. Yesterday we saw a gyrfalcon family with 3 or 4 young in the nest. The young were nearly ready to fledge — at the ‘pantaloons’ stage — very dark brown. They were definitely Best Birds!

Last year a pair nested in Nome, photographed in June 2018 by Mick Thompson.

Gyrfalcon with chick in Nome, Alaska, June 2018 (photo by Mick Thompson via Flickr Creative Commons license)

To learn more about gyrfalcons and see one fly, watch this video of falconer Brian Bradley and his bird at White Memorial Conservation Center in Litchfield, Connecticut.

As you can see, gyrfalcons are not always white.

(photos credits: Tim Lenz via Flicker Creative Commons license, Wikimedia Commons, Black Falcon photo courtesy Glen Tepke, Mick Thompson via Flickr Creative Commons license. Click on the captions to see the originals)

Andean Condors Nest on Camera

Andean condor, Lianni, on her nest at the National Aviary (photo courtesy of the National Aviary)

Andean condors usually nest on inaccessible cliffs 16,000 feet above sea level so it’s a real treat to see a pair nesting on camera at the National Aviary. The condor pair, Lianni and Lurch, expect their egg to hatch June 6-9.

Native to the Andes and nearby Pacific coast, Andean condors (Vultur gryphus) are the world’s largest flying bird. Their 10+ foot wingspan allows them to ride thermals in search of the carcasses of large animals that they scavenge. The condors are so majestic that they’re the national bird of Bolivia, Colombia, Chile and Ecuador and a national symbol throughout the Andean states.

Range (yellow) of Andean condor (map from Wikimedia Commons)

Because the adults have no natural predators Andean condors have evolved to live long a long time (more than 70 years!) and reproduce slowly (only one egg every 1.5 to 2 years).

Unfortunately, due to habitat loss and secondary poisoning from hunted animals, the species is threatened in the wild and critically endangered in Ecuador. Zoos worldwide are participating in an Andean condor breeding program. Lianni and Lurch’s chick will increase the wild condor population.

Watch the condors’ nest on the National Aviary Condor Cam. The link includes a video of Lianni laying her egg.

Stay tuned June 6-9 when the condors’ egg is due to hatch.

(photo courtesy the National Aviary)

First Hatch at Hays Bald Eagle Nest, March 23

First nestling at Hays bald eagle nest, 23 March 2019 (screenshot from Bald Eagles in Western PA – Audubon Facebook page)

Yesterday, 23 March 2019, was a big day at the Hays bald eagle nest. At 8:48am Audubon of Western PA confirmed a pip in one of the three eggs. The egg hatched at 1:14pm.

As usual, the mother bald eagle supervised the hatching process while the father waited for her to tell him ‘all clear.’ What does a father eagle do while he’s waiting? Dana Nesiti of Eagles of Hays PA was on the trail yesterday morning and saw a behavior new to him. He wrote:

… the male grabbed a branch, dropped it while flying and then swooped down and caught it out of the air. Never saw that before.

Dana Nesiti, Eagles of Hays PA on Facebook
Male bald eagle drops a stick that he’s carrying to the nest (photo by Dana Nesiti, Eagles of Hays PA)
… and then he catches it in the air (photo by Dana Nesiti, Eagles of Hays PA)

When the male got the ‘all clear’ he came to the nest to see the chick. Click here for ASWP’s video of the newly hatched chick with mother and father. (The chick is directly below the female.)

For now we will get only glimpses of the chick on camera while his parents keep him warm and incubate the remaining two eggs. But we’ll see him during feedings, as shown at top.

Watch the Hays bald eagle nest on the Audubon Society of Western PA Hays Nest Camera. Join the conversation on YouTube or Facebook.

Two eggs to go. Will both of them hatch? Wait and see.

UPDATE, 25 March 2019, 4pm: Second egg hatched at the Hays bald eagle nest.

(photo at top from Bald Eagles in Western PA – Audubon Society of Western PA on Facebook; in-flight photos by Dana Nesiti, Eagles of Hays PA on Facebook)