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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 explore.org, 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.

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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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TTitmouse-Bryant

Sure, winter is a prime time for feeding birds—natural foods are less abundant and cold weather makes windowside birding that much more inviting. But birds flock to feeders in summer, too—especially in midsummer, after they’ve fledged a brood from their nest and they’ve got new mouths to feed.

Summer bird feeding can bring you different species, such as Neotropical migrants that aren’t around in winter. It’s also a fun time to try offering some different kinds of foods. Here are some tips for creating a summertime backyard buffet that might bring a few new faces to your feeders.

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A Ruby-throated Hummingbird enjoys feeding from a red hummingbird feeder. Photo by Kevin Click via Birdshare.

Nectar for Hummingbirds

Attracting hummingbirds to your yard can be as easy as hanging a hummingbird feeder and filling it with a sugar water solution (1/4 cup sugar per cup of water). There’s no reason to add food coloring to turn the water red; you’re providing a substitute for flower nectar, which is clear. Don’t locate the feeder in direct sun, as the sugar water will spoil rapidly. In the shade your sugar water should last two or three days, except for very hot days, in which case it’s wise to change your hummingbird feeder water daily.

Why are hummingbird feeders red? It’s not because hummingbirds are inherently attracted to the color red, because these peripatetic featherweights feed on flowers of many colors: white, purple, yellow, red, even ultraviolet colors that we can’t see. But the key here lies in the eyesight of nectar-feeding insects, not hummingbirds. Bees, wasps, and butterflies are better at locating pale-colored flowers than red flowers. In nature, red flowers tend to have more nectar in them, because they aren’t being visited as often by insects. So hummingbirds are indeed attracted to red, not because they can see it better, but because they have learned from experience that red flowers tend to have more nectar than flowers of other colors.

Orange & Orange

Baltimore Orioles have a sweet tooth for fruit like oranges. Photo by Dave LaDore via Birdshare.

Oranges for Orioles

Flashy orange orioles are even simpler to lure in for backyard viewing pleasure. Just slice an orange in half and set it on a platform feeder or skewer it on your feeder pole. Other fruits will work too, such as cherries or grapes. Orioles seem to prefer dark fruit and will ignore yellow cherries or green grapes. They also LOVE grape jelly. Put a spoonful of jelly on your platform feeder, and once the orioles find it, it won’t last long!

Why do orioles love fruit? It could be that they develop a sweet tooth while wintering in Central America, where they forage for a variety of wild fruits in tropical forests. Orioles sometimes use their slender beaks to feed in an unusual way, called gaping: they stab the closed bill into soft fruits, then open their mouths to cut a juicy swath from which they drink with their brushy-tipped tongues.

Sunflower Seeds for Grosbeaks

Grosbeaks are one of the best reasons to keep your seed feeders stocked in summer. The males are handsome, decked out in black-and-white formal wear with a pop of color (a red chest patch for Rose-breasted Grosbeaks, warm cinnamon–orange bodies for Black-headed Grosbeaks). Females of both species are drab mottled brown and may be confused with finches or sparrows. Grosbeaks are seed-eating machines. They’ll eat millet but their favorite is good ol’ black-oil sunflower seeds.

Why are grosbeak beaks so big? The better to eat large seeds with, my dear. Grosbeaks are one of the classic birds with beaks that indicate what they eat—big, sturdy beaks are best for crushing seed hulls. Those beaks are also mighty good at crushing insects and grasshoppers, another primary food source. A female grosbeak’s big beak is the first clue that you’re not looking at a finch or a sparrow, both of which have decidedly more petite beaks.

Insectivores like this Eastern Bluebird always welcome a mealworm snack.

Insectivores like this Eastern Bluebird always welcome a mealworm snack. Photo by Lindell Dillon via Birdshare.

Mealworms for Bluebirds

Many people entice bluebirds to take up residence on their property by putting up nest boxes (also called birdhouses). If you have bluebirds in your neighborhood, you can get an up-close look at them by setting a few mealworms out on your platform feeder. Bluebirds are insectivores, and an offering of a few mealworms—alive or dried—is a protein boost that’s hard to resist, especially during the energy-intensive breeding season.

What to do with leftover fishing bait? If you fish with wax worms, set them out for bluebirds. Mealworms and wax worms are interchangeable for bluebirds, and some folks even say bluebirds will pick through a pile of mealworms to eat the wax worms first.

Safety Tips for Feeding Birds Seed in the Summer

Rose-breasted Grosbeaks' big beaks make short work of crushing seed hulls.

Rose-breasted Grosbeaks’ big beaks make short work of crushing seed hulls. Photo by Robin Arnold via Birdshare.

Dr. David Bonter has been studying feeder birds at the Cornell Lab of Ornithology for over a decade. In the course of his research, he fills and maintains more than a dozen bird feeders around Ithaca, New York. Here are his tips for safe bird feeding in summer.

  • Keep your seed dry. Hot, humid summer weather creates the potential for mold. “Some molds produce the byproduct aflatoxin, which is fatal to birds,” Bonter says. He suggests filling feeders halfway in summer and refilling frequently, instead of packing feeders full so the seed sits for long periods. If you find mold on your seed, get rid of it.
  • Move feeders occasionally. Concentrations of seed hulls and bird droppings under a feeder can lead to outbreaks of salmonellosis, a bacterial sickness that can affect birds (and people). Move feeders around the yard and don’t allow waste to build up in one area.
  • Put suet in the shade. Some packaged suet comes in no-melt varieties, but even these can spoil or become soft and foul a bird’s feathers in high heat. Keep suet in cool places. Or, switch to a hummingbird feeder in summer.
  • Clean your feeders regularly. Washing feeders roughly every two weeks with a 10 percent bleach solution will keep your feeders both attractive and healthy for your guests.
  • Be bear aware. Black bear populations are on the rise in much of North America, and the big bruins will absolutely go after your seed stockpiles. Please be aware of potential bear problems in your area and if necessary, take your feeders down during summer to avoid unexpected bear visits.

More resources for bringing birds into your backyard:

(Top image: Tufted Titmouse by Cindy Bryant via Birdshare.)

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colorful tanagers

By Hugh Powell

A study of one of the world’s largest and most colorful bird families has dispelled a long-held notion, first proposed by Charles Darwin, that animals are limited in their options to evolve showiness. The study—the largest of its kind yet attempted—was published today in the Proceedings of the Royal Society B.

The natural world is full of showstoppers—birds with brilliant colors, exaggerated crests and tails, intricate dance routines, or virtuosic singing. But it’s long been thought that these abilities are the result of trade-offs. For a species to excel in one area, it must give up its edge in another. For example, male Northern Cardinals are a dazzling scarlet but sing a fairly simple whistle, whereas the dull brown House Wren sings one of the most complicated songs in nature.

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Naturalists have long noticed that bright, showy birds like the Northern Cardinal often sing simple songs, while plainer birds like the House Wren often sing complex songs. Photos by Judy Howle/Cornell Lab (cardinal) and Gary Mueller/Cornell Lab (wren).

Compare the two songs:
Northern Cardinal:

House Wren:

Animals have limited resources, and they have to spend those in order to develop showy plumage or precision singing that help them attract mates and defend territories,” said Nick Mason, the paper’s lead author.  “So it seems to make sense that you can’t have both. But our study took a more detailed look and suggests that actually, some species can.” Mason did the research as a master’s student at San Diego State University. He is now a Ph.D. student at the Cornell Lab of Ornithology.

Mason and his colleagues tested the idea of trade-offs by looking at a very large family of songbirds from Central and South America, the tanagers. This group consists of 371 species—nearly 10 percent of all songbirds. It includes some of the most spectacularly colorful birds in the world (such as the Paradise Tanager) as well as more drab birds (like the Black-bellied Seedeater). The group also includes both accomplished and weak songsters alike.

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The study compared plumage and song complexity in the tanager family, which has showy species like the Paradise Tanager and more drab birds like the Black-bellied Seedeater. Photos by Joao Quental.

Compare the two songs:
Paradise Tanager:
Black-bellied Seedeater:

The research team examined museum specimens of 303 tanager species, using a spectrophotometer to measure nine aspects of plumage coloration, such as brilliance and contrast. They took a similar approach to the birds’ songs, analyzing more than 2,700 recordings to measure 20 song variables including length, bandwidth, and number of syllables. (By the end of the project, Mason had earned the distinction of being the largest-ever single user of the Cornell Lab’s Macaulay Library sound archives.) Finally, the team compared how plumage and song complexity varied at each of the branches along a recently completed evolutionary tree of the tanager family.

“If there were going to be any group of birds at all that would show this trade-off, the tanagers would be a very good candidate, because there’s all this variation in song and plumage complexity,” Mason said, noting that the group’s large size lends confidence to the statistical analysis. “But when we dive into it and do some rigorous statistics, it turns out that there is no overall trend. Tanagers can be drab and plain-sounding, or colorful and musical, or anything in between.”

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The Blue-winged Mountain-Tanager was ranked #4 in plumage complexity. But it and its close relatives also have complicated songs, contributing to the study’s finding that there is no evolutionary trade-off between plumage and song complexity. Photo by Keith Bowers.

Hear the song:

As a byproduct of the analyses, Mason was able to put together top-10 lists of tanagers with the most colorful plumage and the most complex songs. Those lists help illustrate the overall lack of a trade-off between singing and plumage. For example, a single genus of mountain-tanagers had members on both lists. The Lacrimose Mountain-Tanager ranked #8 among the most complex songs, while the Blue-winged Mountain-Tanager had the fourth most complex plumage of all 303 species examined.

The study puts a significant dent in the idea of evolutionary trade-offs between plumage and song. It’s still possible that trade-offs take place at the level of genus, Mason said, or that they influence species relatively fleetingly as evolutionary pressures appear and disappear. But as a broad effect on an entire family of birds, a voice–plumage trade-off doesn’t seem to exist. One possibility is that the resources needed to develop fancy plumage are different from the ones required for complex songs, freeing tanagers to invest in both forms of showiness simultaneously.

In addition to Mason, the study’s authors include Allison Shultz and Kevin Burns, both of San Diego State University. The research was funded in part by the National Science Foundation and the National Geographic Society.

(Sounds via Macaulay Library: Northern Cardinal by Gerrit Vyn; House Wren by Geoffrey Keller and Thomas Sander; Paradise Tanager and Black-bellied Seedeater by Theodore Parker III, Blue-winged Mountain-Tanager by Mark Robbins. Top images via Neotropical Birds. Clockwise from upper left: Golden Tanager by Peter W. Wendelken, Swallow Tanager by Frank Shufelt, Blue-winged Mountain-Tanager by Keith Bowers, Red-necked Tanager by Vivek Tiwari, Beryl-spangled Tanager by Priscilla Burcher.)

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