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Cornell Lab staff writer Pat Leonard is in Barrow, Alaska, with owl researcher Denver Holt (above), who has been studying Snowy Owls for more than 20 years. Yesterday they visited the owl nest that’s featured on our Bird Cams project. The nest originally had seven owlets, but the researchers know of only two that are still alive. Pat Leonard describes how the nest checkup went:

Every three days this summer, Denver Holt of the Owl Research Institute tries to check each of the 20 Snowy Owl nests he’s monitoring. [Read about a previous nest check.] Today, our goal was to find the two surviving Snowy Owl chicks from our Bird Cams project nest to see if they are still alive and how they are doing. Holt has brought along Cindy Shake of UMIAQ, an organization that provides support for Holt’s research, as another helpful set of eyes. We strike out across the soggy tundra in the vicinity of the live camera to see if we can spot the little ones.

With a light mist blowing on the ever-present wind and the glowering low-slung cloud cover it seems impossible to locate anything small and gray at a distance. The Snowy Owl parents are nearby and they see everything with their super-powered eyesight. They are paying close attention to us, so there may be a chick nearby. As usual, with 23 years of experience under his belt, Holt spies a chick first. It’s hunkered down near a hummock where one of the adults has left a lemming. The chick sees us coming.

Shake and I hang back while Holt moves closer. While he’s concentrating on the chick, Mom swoops by to snatch the lemming for safekeeping. Dad’s remaining a bit passive, something Holt has noted in the past. He expresses nothing but admiration, though, for the female and the job she has been doing. “She’s magnificent!” he declares.

Snowy Owlet788

Biologist Denver Holt holds Snowy Owl chick number 788. Photo by Pat Leonard.

Holt snags the owlet and takes a closer look. Who do we have here? This is chick number 788, according to the last three digits on the leg band Holt put on weeks ago. The owlet’s primaries are growing in nicely and it seems to be the proper size for its age. This chick is 34 days old as of today (July 22) and walked off the nest a couple of weeks ago. This is the younger of the two chicks we hoped to find. Sibling number 787 was the first chick to hatch and the first to leave the nest, just a couple of days before this one.

Holt looks over the bird in his hand and feels confident that this chick is a female. Its dark ashy color is one clue but he also looks at the number four secondary feather. “If it shows spots that don’t reach all the way to the rachis—the shaft of the feather—then it’s a male,” Holt explains. “If the feather shows bars that do reach all the way to the shaft, which is the case with this one, then it’s a female.”

Holt has tested the accuracy of this method by cross-checking field observations with later DNA analysis. The score: 140 correct matches out of 140 chicks whose gender was determined in the field using the feather method. Holt coauthored a paper on these results in the Journal of Raptor Research in 2011.

After a quick visual check, Holt sets the bill-clacking owlet free and she does her hobble-hop away with, I imagine, something akin to relief, if an owl can feel such a thing. After she’s put some distance between us, Mom returns with the lemming and feeds her—a good thing to see. Beautiful number 788 still has another two to three weeks to totter about the tundra before she can take her first awkward flights. Fledging usually takes place when chicks are 45 t0 55 days old. Though we’re happy to have found 788, the overall mortality among this year’s chicks is pretty sobering—about 70% by Holt’s reckoning, though it’s not clear why.

We spend another 15 minutes or so looking in vain for chick number 787. The parents seemed to lose interest in us too, so perhaps we were never even close. However, when we returned home we learned to our relief that several people watching the Bird Cams, including project assistant Hollie Sutherland, had seen the owlet scurry away as we approached.

In the end, we abandon the search so as not to stress the adults any more than necessary because while we are on the scene, they have to be on alert. The goal, as always, is to balance the need for scientific study with the overall wellbeing of the birds being studied. And no one wants to end up on the business end of those razor-sharp claws!

For more about Snowy Owls, check out:

(Top image: Denver Holt examines the spread wings of owlet 788. Markings on the fourth secondary feather [a little farther than halfway along the trailing edge of the wing] can be used to sex young Snowy Owls. Photo by Cindy Shake.)

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In summer many young-of-the-year songbirds fledge from their nests. In seemingly no time at all, midsummer bird watchers are beset by a rush of bland, brownish birds in juvenal plumage.

But don’t despair—there are still plenty of clues to help you get where you’re going. In fact, using just three steps you can get through a process of elimination and arrive at an ID. Let’s take the streaky, brown creature in the above photo as an example:

1. What do we see?
Shape: fairly short, thick, stubby bill
Color pattern: blurry, indistinctly streaked breast, pale bold edges on wing coverts
Behavior: on the ground

2. To which group does this bird belong? One thing to keep in mind with juvenile songbirds—they have adult sized bones when they leave the nest. They may have shorter wings and tails than adults because their feathers are not fully grown, but you can rely on their bill shape and leg length being true to their species.

In this photo, sparrows and finches come to mind because of this bird’s streaks and stubby bill. Also, blackbirds have thick-based, sharply pointed bills and are often on the ground.

3. Which species? This bird’s hefty bill is too thick for a House or Purple Finch. It’s also longer-proportioned and larger than either of the finches.


Here’s the mystery bird compared with a House Finch (right) by Mark Moore.

Female and juvenile Red-winged Blackbirds are similar, but they have a longer, pointier bill and more clearly defined, darker streaks on the head.


Compare the mystery bird with the higher-contrast streaking of a female Red-winged Blackbird (right) by Anne Elliott.

On a Song Sparrow, there is more contrast between the streaks and the overall body color. On the mystery bird we notice streaks, but the entire breast and belly is streaked, uniform in color, and there’s no clear distinction where a streak starts or ends. The mystery bird’s streaked belly means we can cross many sparrows off the list of possibilities—and its hefty bill is even larger than a typical sparrow’s bill.


Here, the mystery bird shows far less contrast—and overall different shape—than a Song Sparrow (right) by Ryan Schain.

The head is fairly plain overall and the eyebrow blends right in, so we also cross off anything with a bold head pattern, such as juvenile Black-headed and Rose-breasted Grosbeaks.


The mystery bird’s large bill is outdone by the Rose-breasted Grosbeak (right, by Kelly Colgan Azar), which also shows a prominent stripe over the eye.

What else is brown and streaky with a thick, short bill? As we mentioned, blackbirds are often found on the ground. They tend to have thick but long, sharply pointed bills. However, Brown-headed Cowbirds—members of the blackbird family—have a distinctive short, thick-based bill. Though the adults are uniformly brown (females) or blackish brown with a brown head (males), juveniles are heavily streaked—and indeed this is a juvenile Brown-headed Cowbird.

For more help on identification:


(Mystery bird photo: juvenile Brown-headed Cowbird by Flipkeat via Birdshare.)

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Cornell Lab writer Pat Leonard is in Barrow, Alaska, with Snowy Owl researcher Denver Holt of the Owl Research Institute. Holt’s organization, along with, were responsible for setting up the Snowy Owl cam featured on our Bird Cams project in summer 2014. Leonard visited Holt for some fieldwork in the damp, chilly summer of far northern Alaska. 

First: a quick lesson in shifting gears on an ATV—the ubiquitous mode of transport in Barrow when there’s no snow on the ground. Then field researcher Denver Holt of the Owl Research Institute, barrels off in the lead, taking us about 10 miles out of town to nest #8. (Note to Bird Cams fans: this is not the same nest as is shown on the Snowy Owl cam, though Leonard hopes to visit that nest in a few days.)

It’s a cold day (about 35 degrees Fahrenheit) made colder by the wind and colder still by open-air transportation. Both of us are bundled to the eyes in multiple layers. Sometimes even that is not enough. But hiking provides more than a useful means of covering the terrain—it warms you up. We’re heading about a mile out from the dirt track, just specks of humanity in a vast landscape with few reference points as we circle a small freshwater lake to get to the nest.

The wide vista is sliced neatly in two:  gray overcast above, the flat tundra below in muted greens and browns. It’s spongy and soft when you walk on the drier parts; wet areas are not deep but the ridges and bumps could easily grab and twist the ankles of the inattentive.

Along the way, there’s much to see and a lot to learn in the company of a skilled guide. Holt is a walking encyclopedia when it comes to the tundra. “Those are marsh daisies and buttercups,” he says, pointing to tiny pips of color, flowers that look so fragile and yet endure in one of the harshest environments. He can explain how the mounds have built up over thousands of years due to freezing and thawing of the upper layers of the tundra and the pressure exerted by subterranean ice ridges.

As we get closer to the unnamed lake we see Yellow-billed Loons, then a cluster of oh-so-lovely Pacific Loons with their sleek gray necks. Red Phalaropes are skittering around while a Glaucous Gull floats on the wind above and seems to be chuckling at the clumsy humans trudging below. But nearby are the remains of a gull that was taken by a Snowy Owl recently, according to Holt. It seems as if he knows every move they make. But is there a chick or chicks still around nest #8?

Snowy Owl chick

A Snowy Owl chick—about 25 days old—just before banding. Photo by Pat Leonard.

A flash of white. There’s the big female in the distance, watching us. Then Holt hears a sound that I miss beneath the white noise of the wind. There’s the male! “He’s barking at us, that’s a good sign that there might be a chick nearby,” says Holt.

We don’t know for sure where the chick or chicks will be. Snowy Owl chicks spend their first three weeks on the nest being brooded by their mother. After that period, while they’re still downy, gray, and flightless, they split up and wander away from the nest, possibly to make them less visible to predators. They won’t be able to fly for another three or four weeks. During this time, finding them on the endless, hummocky tundra is quite a challenge, even for an experienced researcher like Holt.

Then, crouched behind the nest mound, there’s the owlet—a small gray ball of fluff with golden eyes and the beginnings of wing feathers. (We really don’t know the chick’s gender but we seem to want to refer to it as “he.”)

Holt pulls out his banding materials and the record book for this nest. It holds all the data, such as egg measurements, number of chicks, etc. He’s been spending the “balmy” summer months in Barrow to collect this data for 23 years. This nest had seven eggs to start with, and seven chicks hatched. But as far as Holt can tell, this one undersized chick is the only survivor. The eggs in all 20 nests he’s monitoring this season hatched just fine, but it seems all the nests have had several chicks die. Holt isn’t sure why. The brown lemmings that Snowy Owls feed on and seem to require to trigger breeding, have been present in so-so numbers—not a boom, but not a bust either.

Our little chick clacks his bill and peeps as Holt looks him over and claps a silver band around his leg. He’ll be monitored again soon. Holt tries to visit every nest every three days to track the chicks’ progress. He feels this chick should be farther from the nest for his age. We both hope he will make it. Mom and Dad are still nearby watching carefully but not attacking. Some pairs are more aggressive and will dive at intruders with those wicked long claws flexed to do damage.

Except for when we banded the chick, we’re always on the move. Holt says that’s the way you find most of the chicks now that they are off the nest but can’t fly yet. Keep scanning the ground for something moving in the general vicinity of a nest and hope to see a small form tottering around the tundra like a little gray gnome.

This is part of a day in the life of a Snowy Owl field biologist, where success may be defined as locating a lone speck of fluff on the vast tundra, marking it with evidence of its encounter with humans. You hope one day to find it again and in doing so unravel another small piece of the Snowy Owl puzzle: why do they do what they do, and why do they go where they go?

Pat Leonard wrote about Snowy Owls in the spring 2014 Living Bird magazine, and about Project SNOWstorm during the great winter irruption of 2013–2014.

(Top image: Denver Holt records data on the Alaskan tundra, by Pat Leonard.)

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Conventional wisdom tells us that birds migrate north in spring and south in autumn. Some species also migrate in summer, though these movements are more modest and regional, rather than long-haul, intercontinental voyages. And they often head in counterintuitive directions as birds seek out specific seasonal resources instead of making  a beeline for their winter range.

Scientists call these movements molt migrations or postbreeding dispersal. We’ve compiled the following examples of birds on the move from all over North America, and we explain the reasons below. It all adds up to extra incentive to keep your eyes peeled—you may notice new birds coming and going all summer long.


1. Adult male King Eiders leave their mates partway through nesting and fly off to grow a new set of feathers. Hundreds of thousands of eiders pass by Pt. Barrow, Alaska, in July on their molt migration to the Bering Sea.

2. Surf Scoters leave their breeding sites in Quebec and Labrador to grow new wing feathers in the St. Lawrence River estuary.

3. In July and August, adult male Rufous Hummingbirds are among the first birds to head south toward their wintering grounds in Mexico.

4. Arctic-breeding shorebirds, including Least Sandpipers, begin turning up in the lower 48 states by the end of June. These are adults that likely failed in their breeding attempts, so they didn’t have to stick around to raise young.

5. After breeding, adult and juvenile heron and egret populations shift slightly northward. Little Blue Herons wander well north of their breeding range in the late summer.

6. After fledging, the juveniles of several species of raptors move north. On days with a southwest breeze in August, upwards of 1,000 juvenile Red-tailed Hawks can be seen flying along the shore of Lake Ontario. Bald Eagles also cruise north in the summer.

7. Several species that breed along the Baja Peninsula, including Heermann’s Gull, disperse north along the coast after breeding, some heading all the way up to Vancouver.

8. A number of western songbirds—including Lazuli Bunting and Lark Bunting—head to the Mexican monsoon region as their breeding sites dry up in late summer. The monsoons unleash a flood of food, such as flowering plants and insect hatches, that these birds can feast on to refuel during the energetically intense molting period. After growing a new set of feathers, they continue south to wintering grounds in Mexico and Central America.

More resources for understanding migration:

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