Category Archives: Migration

Tundra Swans Overhead

Tundra swans in flight (photo by Steve Gosser)
Tundra swans in flight (photo by Steve Gosser)

This week's cold weather bought winds from the north and flocks of tundra swans over western Pennsylvania.  We usually hear them first, rush out to see them fly ... and then they're gone.

Where did they come from?  Where are they going?

Most of "our" tundra swans breed in the north central territory of Canada (Nunavut) and north of Hudson Bay.  This map from Xeno Canto shows their path in North America.  (Breeding range is pink.  Migration corridors are greenish yellow.  Wintering sites are blue.  I've added a purple dot for our location in western Pennsylvania.)

Map of Tundra Swan breeding, migration and wintering in North America (from Xeno Canto with location of recordings)
Map of Tundra Swan breeding, migration and wintering in North America (from Xeno Canto with location of recordings)

In late September tundra swan families assemble into flocks.  Then "our" swans move south through Canada's prairies, arriving in North Dakota and the upper Mississippi River valley in early October where they eat and wait until winter hits.

On winter's first blast they fly southeast to Chesapeake Bay and eastern North Carolina, passing over Pennsylvania on their way.

Tundra swans typically fly 30 miles per hour but on a strong northwest wind they can clock 100 mph and fly non-stop for 1,000 miles.

Most flocks don't stop in western Pennsylvania but they take a break here if the "kids" get tired.  That's what happened on Tuesday at Crooked Creek Lake.

Marge Van Tassel and a group of volunteers heard the swans coming and drove to a good vantage point to watch them come in.  Marge's photo shows them descending to the lake like large beautiful snowflakes.

Tundra swans landing at Crooked Creek, 7 Nov 2017 (photo by Marge Van Tassel)
Tundra swans landing at Crooked Creek, 7 Nov 2017 (photo by Marge Van Tassel)

 

Listen for their sound overhead and you may see tundra swans, too.

 

(photo credits:  flock in flight by Steve Gosser, flock landing by Marge Van Tassel, map and audio clip recorded in Michigan by Allen T. Chartier, #XC11851 from Xeno Canto)

Not A Sparrow, Not A Thrush

American pipit, Algonquin Provincial Park, Canada (photo from Wikimedia Commons)
American pipit, Algonquin Provincial Park, Canada (photo from Wikimedia Commons)

Not a sparrow, not a thrush, he's on his way to Georgia ... sort of.

American pipits (Anthus rubescens) nest in alpine and arctic tundra and winter in open country from the southern U.S. (including Georgia) to Guatemala.  Right now they're on the move through western Pennsylvania, but because our area lacks tundra the best place to find pipits is on mudflats.  And where are those?

Last Sunday a bunch of us stopped at Somerset "Not a Lake" in Somerset, PA to look for birds.  The lake was drained to repair the dam and out on the mud roamed killdeer, dunlin and other shorebirds.  Among them were two songbirds that pecked the mud, darted, zigzagged, ran and jumped. American pipits.

We could hear them, too.  Here's a loud pipit (with a soft longspur in the background):

On Throw Back Thursday this vintage article that lists why pipits aren't thrushes.  Back in 2010 it was posed as a quiz, but I've already told you the answer  😉    Quiz: Not A Thrush.

 

(photo from Wikimedia Commons; click on the image to see the original)

Small Ducks Stop By For a Visit

Bufflehead female with two males (photo by Steve Gosser)
Buffleheads, female with two males (photo by Steve Gosser)

It's early November, the wind's from the north, and it's time for waterfowl. Here are two small ducks who stop in southwestern Pennsylvania on their way south.

Buffleheads and ruddy ducks hang out together in the winter, perhaps because they dive for the same food:  aquatic insects and crustaceans (crabs, crayfish, etc).  Buffleheads add mollusks to their diet (small mussels, clams, etc).  Ruddy ducks add plants and zooplankton.

Buffleheads (Bucephala albeola) are black and white with compact bodies and stubby bills.  Only 13.5 inches long, they fly fast and land abruptly.  They're actually the same size as a pied-billed grebe(*) but bufflehead males look larger because their round white-topped heads stand out.

Male bufflehead (photo by Steve Gosser)
Male bufflehead (photo by Steve Gosser)

Identifying female buffleheads is tricky, though, because their black heads have a white splash on the cheek that resembles -- at long distance -- a male hooded merganser or a female ruddy duck.

The best clue to a female bufflehead is that she's close to the males, as you can see in Steve Gosser's photo at top.

While buffleheads look like large ducklings, ruddy ducks (Oxyura jamaicensis) are shaped like bathtub toys(*).  At only 15 inches long they have big heads, thick necks and large slightly upturned bills.  Just like rubber duckies they often cock their tails, especially when asleep.

Ruddy duck (photo by Steve Gosser)
Ruddy duck swimming (photo by Steve Gosser)

In November ruddies are less "ruddy" than in the breeding season but the male retains his white cheek.

Ruddy duck male, late non-breeding plumage (photo by Steve Gosser)
Ruddy duck male, late non-breeding plumage (photo by Steve Gosser)

Females and juveniles have off white cheeks with a faint brown line.

Female ruddy duck (photo by Steve Gosser)
Female ruddy duck (photo by Steve Gosser)

 

Though buffleheads winter as close to us as Ohio, neither species stays in Pittsburgh for the season.  Stop by our rivers and lakes to see these ducks before they leave.

 

(photos by Steve Gosser)
(*) Descriptions adapted from Pete Dunne's Essential Field Guide Companion, an excellent resource for birding.

The Wax Eaters Are Back In Town

Yellow-rumped warbler in autumn (photo by Cris Hamilton)
Yellow-rumped warbler in autumn (photo by Cris Hamilton)

After most warblers have left for the winter, the yellow-rumped warblers come back to town.

Breeding across Canada and the northern U.S., yellow-rumped warblers (Setophaga coronata) spend the winter in North America as close to us as Ohio and eastern Pennsylvania, though not usually in our area.  In late fall they stop by in Pittsburgh.

Yellow-rumps don't have to leave for Central or South America because they have a unique talent. Their bodies can digest wax.  In winter they eat the waxy fruits of bayberry and juniper.  Since bayberry is also called wax myrtle, it gave our common subspecies its name:  the myrtle warbler.

On Throw Back Thursday, learn how yellow-rumped warblers get nutrition from wax in this vintage article:  Anatomy: Wax Eaters.

 

p.s. Notice that the warbler in the Wax Eaters article is wearing bright breeding plumage in black, white and yellow . Autumn yellow-rumps are dull brown with a faint vest and a broken white eye ring. The best clue to their identity is their yellow rump.

Yellow-rumped warbler showing its yellow rump (photo by Cris Hamilton)
Yellow-rumped warbler showing its yellow rump (photo by Cris Hamilton)

(photos by Cris Hamilton)

They’re Back!

American crows (photo by CheepShot via Wikimedia Commons)
American crows (photo by CheepShot via Wikimedia Commons)

The crows are back in town!

Tuesday evening (October 23) Michelle Kienholz sent me the photo below of a huge flock of crows flying over Schenley Park toward CMU at 6pm.  See those specks above the horizon?  Hundreds of them!

Flock of crows flying toward CMU at dusk, 23 Oct 2017, 6:07pm (photo by Michelle Kienholz)
Flock of crows flying toward CMU at dusk, 23 Oct 2017, 6:07pm (photo by Michelle Kienholz)

Yes, it's late October and the crows are back in Pittsburgh for the winter.  This is just the beginning of the flock.  More will follow.

In the next few weeks the crows will move their roost several times until they settle on a favorite safe place.  Meanwhile, you'll see them at dawn and dusk flying down the Allegheny River valley and through Oakland.

Last year crows made the news by plaguing Pitt's campus:  Annual crow stopover makes work for Facilities.

Will they roost at Pitt this year?  Stay tuned.

 

(photo credits: three crows by CheepShot on Wikimedia Commons; click on the image to see the original.  Crows darken the sky near CMU by Michelle Kienholz)

We Migrate Five Days Later Now

Golden eagle at Allegheny Front Hawk Watch, 1 Nov 2016 (photo by Steve Gosser)
Golden eagle at Allegheny Front Hawk Watch, 1 Nov 2016 (photo by Steve Gosser)

Twenty-one years ago I attended my very first hawk watch on a spectacular golden eagle migration day -- 26 October 1996 at the Allegheny Front Hawk Watch.

Nowadays when I want to see a lot of golden eagles I visit the Allegheny Front in early November because that's when the eagles fly by.  Is it my imagination or are the birds migrating later than they used to?   A new study published last month in The Auk: Ornithological Advances confirms that raptors' autumn migration has shifted later.

The study, conducted by Hawk Mountain Sanctuary, analyzed hawk count data for 16 raptor species from 1985 to 2012 at 7 hawk watch sites in eastern North America:  Hawk Mountain Sanctuary (Kempton, PA), Hawk Ridge (Duluth, MN), Holiday Beach (Ontario, Canada), Lighthouse Point (New Haven, CT), Montreal West Island (Québec, Canada), Mount Peter (Warwick, NY), and Waggoner's Gap (Landisburg, PA).

The 16 species included both long distance migrants traveling to South America such as broad-winged hawks, and short distance migrants that stay in North America such as sharp-shinned hawks and golden eagles.  Each species adjusted its peak migration, but the delays were pronounced for short distance migrants.

To parse out the reason why raptors stay north longer, the study compared climate and air temperature data in the birds' breeding areas to the timing of migration during the 28 year period.

As you can see from this NOAA map from October 2012, the climate warmed in the breeding zone in eastern North America (marked with a yellow square).  Click here to see the details on the study's map.

Land & Ocean Temperature Anomalies, 1981-2010, NOAA (image from NOAA) Yellow square shows region of the hawk migration study.
Land & Ocean Temperature Anomalies, 1981-2010, NOAA (image from NOAA) Yellow square shows region of the hawk migration study.

Because the warming climate delays the first frost, plants and insects remain abundant later in the year. This abundance ripples all the way up the food chain to raptors who postpone their fall departure.  The study found that the shift in migration matches the pace of warming climate.

Golden eagles demonstrate the trend. Between 1985 and 2012 they waited an additional 0.16 days/year before moving south.  By 2012, the delay was 4.48 days.   Extrapolating to 2017, golden eagles are leaving 5.12 days later now than they did in 1985.

Whats' more than five days after October 26?   November 1.  So I'm going to the Allegheny Front Hawk Watch in November.

Click here to read about the study and download the full report.

 

p.s. Three species have delayed autumn migration even more than golden eagles: Sharp-shinned hawks added 0.2 days/year, northern goshawks added 0.21 days/year and black vultures added 0.40/year.

(photo by Steve Gosser)

When Will The First Junco Arrive?

Dark-eyed Junco (photo by Bobby Greene)
Dark-eyed Junco (photo by Bobby Greene)

Since mid-September summer has lingered in Pittsburgh with temperatures spiking 15-20 degrees above normal.  Does this mean fall arrivals will be delayed?

Here's what normally happens outdoors in late October and early November.  Let's watch to see if it's on schedule.

  • Fall colors peak in mid-October, especially red and sugar maples.  The oaks turn red at the end of the month.
  • First frost in Pittsburgh around October 20.  First hard frost around Halloween. (Really?!?  Keep your eye on this one.)
  • Most trees will lose their leaves by November 8.
  • Most flowers have gone to seed though witch hazel, bottle gentian, hardy goldenrods and asters are blooming.
  • The warblers are gone but white-throated sparrows, dark-eyed juncos and American tree sparrows will arrive to stay through winter.
  • Broad-winged hawks are gone but red-tailed hawks, kestrels and sharp-shins are now on the move. Don't miss seeing golden eagles at the Allegheny Front Hawk Watch from late October through November.
  • Fill your hummingbird feeder in October in case a rufous hummingbird shows up.
  • Big flocks of robins, grackles and starlings form at dusk and dawn. The Pittsburgh crow flock becomes noticeable in early November.
  • The first wave of migrant ducks and geese arrive with October cold fronts.
  • Chipmunks, squirrels, and groundhogs are storing food and putting on weight.
  • It's hunting season. Wear blaze orange and be aware of Pennsylvania’s hunting seasons.  Remember: Though Sunday is generally safer, some game can be hunted on Sundays.
  • Be prepared to "fall back" on the first Sunday in November when we set our clocks to Standard Time.  After that, evening rush hour will be in the dark.

When will the first frost come? When will the first junco arrive?

Stay tuned.

For more information, see Chuck Tague's Western Pennsylvania Phenological Perspective for October, first published in 2010.

 

(photo by Bobby Greene)

Where to Find Crossbills and Siskins This Winter

White-winged crossbill, 2012 (photo by Shawn Collins)
White-winged crossbill, 2012 (photo by Shawn Collins)

Will we see northern finches in the eastern United States this winter?  It depends on where you are.

Last month Ron Pittaway published his Winter Finch Forecast for 2017.  The good news is that northern finches are on the move.  The bad news for Pittsburgh birders is that they won't come this far south.

Northern finches such as evening grosbeaks, crossbills, redpolls and purple finches don't care about cold weather but they do care about food and that means seed cones on spruce, fir, pine and birch trees.

Pittaway says that seed crops in northeastern North America are excellent this year -- the best they've been in ten+ years -- so finches have already moved to those areas in good numbers.  In fact the seed crop is so good up north that purple finches and evening grosbeaks probably won't leave home this winter.

The Winter Finch Forecast predicts that if you're in central or northeastern Ontario, Quebec, Canada's Atlantic provinces, northern New York state, or northern New England, you'll see red crossbills (Loxia curvirostra), white-winged crossbills (Loxia leucoptera) and pine siskins (Spinus pinus) this winter.

But not here.  As he says, "This is not an irruption year south of traditional wintering areas in the Northeast."

Read the entire forecast here including predictions for three indicator species: blue jays, red-breasted nuthatches, and Bohemian waxwings.

The blue jay prediction surprised me.  We have a big influx of blue jays in Schenley Park right now. I wonder where they came from.

 

p.s. I saw red-breasted nuthatches at Cape Cod last week.

(photo of a white-winged crossbill by Shawn Collins, 2012)

Staging At The Cape


Flock of Tree Swallows by Cindy Bryant on Vimeo, 12 Jan 2015, Central Florida.

Last weekend at Cape Cod I saw a swirling flock of tree swallows at their staging area.

Staging: Designating a stopping-place or assembly-point en route to a destination -- from The New Shorter Oxford English Dictionary.

Tree swallows (Tachycineta bicolor) breed as far north as the tundra/tree line in Canada and Alaska and spend the winter from Florida to Central America.  Their departure from western Pennsylvania is barely noticeable but on the East Coast they gather in salt marshes in huge flocks of a hundred thousand birds.  Their interim stops on migration are called staging areas.

In the evening tree swallows funnel down to the marsh in a tornado of birds.  At dawn they burst up from the roost, as shown in the Central Florida video above.

Last Saturday I saw thousands of tree swallows flying in tight formation at West Dennis Beach.  Though sunset was two hours away they flew low across the salt marsh, hovered and touched down on bushes, swirled up and around and away.

At the height of their swirling I took some photos but couldn't capture their magic.  However, this picture shows why they flew so fast and so close.  There's a falcon in the upper right corner with a swallow in its talons.  Perhaps it's a merlin.  I would never have noticed without this photo.

Thousands of tree swallows and one falcon with prey, West Dennis Beach, MA, 1 Oct 2017 (photo by Kate St.John)
Thousands of tree swallows and one falcon with prey, West Dennis Beach, MA, 1 Oct 2017 (photo by Kate St.John)

Here's an audio description of the tree swallows' fall migration at Connecticut salt marshes at Living On Earth: BirdNote®: Roosting Tree Swallows

It's worth an autumn visit to the East Coast to see this.

 

(video by Cindy Bryant on Vimeo, photo by Kate St. John)

The Route He Takes Is Life Or Death

Common cuckoo in flight (photo from Wikimedia Commons)
Common cuckoo in flight (photo from Wikimedia Commons)

When a migratory bird population is declining, what's the cause?  Is it poor breeding success? Perils during migration? Decline on the wintering grounds?  Or all of the above?

For common cuckoos in the U.K. there's a surprising answer. Though equally successful on their breeding and wintering grounds the birds have two fall migration routes, one more dangerous than the other.  The population that takes the deadly route is declining.

Researchers attached tiny transmitters to 42 male common cuckoos (Cuculus canorus) across the U.K. and tracked them on migration from 2011 to 2014.  All of the birds spend the winter in Central Africa but they choose two routes during fall migration.  The eastern route goes east over Europe then south over Italy, the Mediterranean, and the Sahara.  The western route is a shortcut over France, Spain and the western Sahara.  Mortality was highest along the western route, especially in Spain.

Cuckoos that breed in Scotland and Wales take the long eastern route in the fall.  Cuckoos nesting in southern England split with about 60% flying east, the remainder taking the west shortcut.  Midlands and East Anglia cuckoos favor the western route.

Common cuckoos have a stable population in Scotland and Wales but a declining one in the midlands and eastern England.  When the researchers matched migration routes with population trends in the Breeding Bird Survey and Bird Atlas they found a close correlation.  Indeed, population decline in the common cuckoo is linked to their choice of migration route.

See the migration maps and read the 2016 study here at Nature Communications: Population decline is linked to migration route in the Common Cuckoo.

 

(photo of common cuckoo from Wikimedia Commons; click on the image to see the original)