Category Archives: Migration

Which Birds Will Visit This Winter?

Migration
Two evening grosbeaks in flight, western Washington State (photo from Wikimedia Commons)

14 October 2024

When North Americans go south for the winter they do it to escape the cold. When boreal finches leave Canada in autumn it’s not about cold, it’s about food.

Winter finches are cold hardy and could stay up north all year but when seed cones and fruit are in short supply they fly south to find food. Every year the Finch Network examines finch food crops across Canada and predicts southward movement by species. Their 2024-25 Winter Finch Forecast came out in late September, summarized below.

This winter we will NOT see these species.

  • Pine grosbeaks (Never come to southwestern PA anyway.)
  • Redpolls
  • White-winged crossbills
  • Red crossbills
  • Redpolls (It feels like a very long time since redpolls came to PA.)
  • Bohemian waxwings (Never come to southwestern PA anyway.)

But we may see …

Purple finch (Haemorhous purpureus)

Purple finch (photo by Chuck Tague)

This year, the majority should leave Canada with a likely moderate flight to the Great Plains and southern United States. … At feeders, they prefer black oil sunflower seeds.

— 2024-25 Winter Finch Forecast

Pine siskin (Spinus pinus)

Pine siskin in Quebec province (photo from Wikimedia Commons)

Areas from Manitoba eastward affected by Spruce Budworm infestations have a poor cone crop. Siskins that bred in these areas will be on the move. While band recoveries show siskins will move straight across North America from coast to coast, there should be some small movement south in the eastern half of the United States this fall in search of food. 

— 2024-25 Winter Finch Forecast

Evening grosbeak (Coccothraustes vespertinus)

Evening grosbeak, January 2013 (photo by Steve Gosser)

Spruce budworms caused problems with the cone crop this summer but there were lots of berries. However, the berries gone now so…

Evening Grosbeaks should visit areas from the Maritime provinces south towards Pennsylvania. Areas even further south to the mid-Atlantic states may see grosbeaks this winter.

— 2024-25 Winter Finch Forecast

These species are not finches, but are part of the prediction.

Red-breasted nuthatch (Sitta canadensis)

Red-breasted nuthatch (photo by Chuck Tague)

Because of patchy balsam fir cones, there should be a moderate to strong flight of red-breasted nuthatches into the U.S.

Blue jay (Cyanocitta cristata)

Blue jay at Frick Park (photo by Charity Kheshgi)

In eastern North America westward to Manitoba the deciduous tree crop (they love acorns on oaks) appears below average with scattered areas of average crops, so expect a moderate to strong flight this fall. 

— 2024-25 Winter Finch Forecast

I’ve already seen lots of blue jays passing through!

Tick Season Returns — On Birds

Insects, Migration
Connecticut warbler banded at Hays Woods with engorged tick above eyering, 8 October 2024 (photo by Nick Liadis, Bird Lab)

9 October 2024

Yesterday while Bird Lab was at Hays Woods, Nick Liadis captured and banded a Connecticut warbler! I was not there to see this rare bird (alas) but Nick sent me a photo. Notice that the warbler has an engorged tick at top right of his eye-ring.

Tick season has returned with a vengeance after a low period during August and September’s drought. Because they cannot live without moisture ticks hang out in humid vegetation, but there was very little available during the drought. All that has changed with the recent rains and black-legged ticks are now active for their mating season which they conduct on the bodies of deer. I was reminded of this yesterday when I saw a deer in Schenley Park with three engorged ticks on its face. (Ewwww!)

Birds that forage on the ground are likely to encounter ticks so its no surprise that the Connecticut warbler and this song sparrow acquired them.

Song sparrow with engorged tick below its eye
(photo from Scott, & Clark, Kerry & Coble, & Ballantyne,. (2019). Detection and Transstadial Passage of Babesia Species and Borrelia burgdorferi Sensu Lato in Ticks Collected from Avian and Mammalian Hosts in Canada. Healthcare. 7. 155. 10.3390/healthcare7040155)

Birds, in fact, are an integral part of the tick’s life cycle. Notice the robin in the Summer section of the CDC diagram below.

Black-legged tick life cycle (diagram from CDC enhanced with lifeform names)

I used to say that deer were the black-legged ticks’ long distance transport system but I’ve changed my mind. It’s birds. A 2015 study found that 3.56% of the songbirds migrating north into Texas in the spring are carrying tick(s), most of which are native to Central and South America.

The bird-tick transport system works both ways. A 2019 tick-host-pathogen study in Canada found that some birds carry ticks with pathogens on fall migration.

Poor birds! They need all the strength they can get to complete their migration. It doesn’t help when ticks are sucking their blood.

Meanwhile, be careful about ticks out there! Lyme disease, transmitted by ticks, is terrible. Check your clothing while you’re in the field and thoroughly check your body for ticks when you return home. Click here for ways to prevent infection by keeping ticks off your clothes and body.

p.s. Support Nick Liadis’ efforts with a donation at Bird Lab’s GoFundMe site.

Visiting Birds Find New Insect Snacks

Bird Behavior, Migration
Immature yellow-bellied sapsucker near spotted lanternflies, Frick Park, 6 Oct 2024 (photo by Charity Kheshgi)

8 October 2024

Bird migration was intense over Pittsburgh on Friday night, 4 October, when more than 20,000 songbirds flew south overhead. We saw the results on Saturday morning in Frick Park where a new cohort of species had arrived with good news: Some of them were eating spotted lanternflies!

The new species included ruby-crowned kinglets, white-throated sparrows, yellow-bellied sapsuckers and yellow-rumped (myrtle) warblers. The mix was quite a change from September’s warblers.

Most of the new arrivals were feeding on tiny insects but the juvenile sapsucker, pictured above, was attracted to sweet lanternfly honeydew on ailanthus trees. He was too young to have ever seen a spotted lanternfly but he was curious. “Are these edible?”

Immature yellow-bellied sapsucker looking at spotted lanternflies, Frick Park, 6 Oct 2024 (photo by Charity Kheshgi)

Yes.

Perhaps the sapsucker got the idea from a northern cardinal that ate a lanternfly further down the trail. (I don’t have a photo of that incident; this one is from iNaturalist, New York.)

Northern cardinal eating spotted lanternfly, NYC (Creative Commons photo by
matthew_wills via iNaturalist)

Olive-sided flycatchers eat spotted lanternflies, too, though they don’t contribute much in Pittsburgh because they are rare here.

Olive-sided flycatcher (photo from Wikimedia Commons)

However, when an olive-sided flycatcher was passing through Howard County, Maryland in early September Mei Shyong photographed it eating a spotted lanternfly. The thumbnail below is just a hint. Click here or on the image to see her photo at Howard County Concervancy on Facebook.

Black Terns Here and There

Migration, Spain, Andalusia, Water and Shore
Black tern in flight, Missouri, May 2017 (photo by Andy Reago & Chrissy McClarren via Wikimedia Commons)

30 September 2024

Yesterday afternoon a black tern (Chlidonias niger) made Allegheny County’s Rare Bird Alert when it was spotted at the main pond at Imperial. Immediately I thought of the black terns I’ve seen during spring migration at the Great Lakes with gorgeous black heads and bellies.

But black terns are not black at this time of year. I didn’t know this until we saw them from the beach at Chipiona, Spain on the WINGS Spain in Autumn tour.

In early September their bellies and faces turn white, like this one in Chipiona in early September 2024.

As time passes they become even paler. If you happened to see the black tern at Imperial yesterday it would look more like this.

Black tern in Ohio, Sept 2014 (photo from Wikimedia Commons)

Black terns live in both the New and Old Worlds. The North American subspecies (C. n. surinamensis) spends the winter on the coasts of Central and South America. The Eurasian subspecies (C. n. niger) migrates across the Mediterranean and the Atlantic coast to Africa.

Black tern range map from Wikimedia Commons

They don’t look like “black” terns in non-breeding plumage. This group was filmed in January 2018, probably in Africa.

embedded video by Michael Autumn on YouTube

Seen This Week: Bird Banding at Hays Woods

Migration, Songbirds
Bay-breasted warbler, Bird Lab banding at Hays Woods, 24 Sep 2024 (photo by Kate St. John)

28 September 2024

As I mentioned in Meet the Baypoll, I visited Bird Lab’s Hays Woods banding station on Tuesday where I had up close looks at warblers and thrushes. Stars of the show were a bay-breasted warbler and a blackpoll captured in the same mist net. I got good photos of the bay-breasted warbler (Setophaga castanea) both front and back. I think he’s more confusing from the back.

Bay-breasted warbler, Bird Lab banding at Hays Woods, 24 Sep 2024 (photo by Kate St. John)

Here he is with his blackpoll buddy.

Bay-breasted and blackpoll warblers side by side, Bird Lab banding at Hays Woods, 24 Sep 2024 (photo by Nick Liadis)

Tuesday was a big day for Tennessee warblers (Leiothlypis peregrina). At least six were banded while I was there. They are hard to identify in autumn because so many of them are unremarkable immature birds without the classic dark olive back and gray head of breeding males. For example …

Tennessee warbler, Bird Lab banding at Hays Woods, 24 Sep 2024 (photo by Kate St. John)

… and another example, though this one has a dark olive back.

Tennessee warbler, Bird Lab banding at Hays Woods, 24 Sep 2024 (photo by Kate St. John)

During the banding process the bander fans the bird’s wings to look for its wing molt stage, a method for aging the bird. Here’s a close look at a Tennessee warbler’s wing.

Tennessee warbler in bander’s hand, wing fanned to examine molt, Bird Lab banding at Hays Woods, 24 Sep 2024 (photo by Kate St. John)

And finally, Tuesday was also a big day for Swainson’s thrushes (Catharus ustulatus). In the hand you can easily see the bird’s identifying feature, its buffy eye ring, but I was surprised by two things I’d never noticed before:

  • Swainson’s thrushes have a two-tone beak. The lower mandible is not as dark at the face as it is at the tip.
  • Swainson’s thrushes are small birds, though larger than warblers.
Swainson’s thrush, Bird Lab banding at Hays Woods, 24 Sep 2024 (photo by Kate St. John)

As I said before, if you’d like to see birds up close during fall migration, visit Nick Liadis’ Bird Lab website and scroll down to the list of three banding locations — Hays Woods, Upper St. Clair and Twin Stupas in Butler County — with instructions for contacting him to set up an appointment.

Learn more about Bird Lab on Wednesday 2 October when Nick Liadis presents Studying Migration Across a Landscape Gradient: Bird Banding in Urban, Suburban, and Rural Habitats at the Three Rivers Birding Club meeting at Beechwood Farms (and on Zoom).

Don’t forget to support Nick’s efforts with a donation at Bird Lab’s GoFundMe site.

Meet the Baypoll

Migration, Songbirds
Baypoll = Bay-breasted warbler (left) + Blackpoll warbler (right). photo by Nick Liadis, Bird Lab banding station at Hays Woods

26 September 2024

Two species of North America’s fall warblers are so easy to mistake for each other that the pair has gained a nickname. Meet the “baypoll.”

On Tuesday I visited Bird Lab’s Hays Woods banding station for an up-close look at fall migrants. That morning Nick Liadis and Shana banded magnolia warblers, Swainson’s thrushes, Tennessee warblers, ovenbirds and many other species. Best Birds were the two pictured above, found in the same net at the same time: a bay-breasted warbler and a blackpoll warbler. Were they traveling together? Maybe. See yesterday’s blog.

These two species look so much alike in autumn that birders joke that they’ve seen a baypoll when they aren’t sure which one it is. Baypoll = BAY-breasted / blackPOLL. eBird doesn’t accept that designation, of course, but it’s useful for describing our frustration.

How can you tell the two apart?

In non-breeding plumage the bay-breasted warbler (Setophaga castanea) has bold wingbars with a dark bar between them and often, but not always, a faint bay (chestnut) wash on its flanks. It also has dark feet and an unstreaked breast. Compared to other warblers the bay-breasted looks long and bulky, not petite.

Bay-breasted warbler, Sept 2022 (photo from Wikimedia Commons)
Bay-breasted warbler, Sept 2015 (photo from Wikimedia Commons)

Blackpoll warblers (Setophaga striata) are striped, striata, where the bay-breasted is not. Even when the stripes are faint you’ll see them at the sides of the breast. Wingbars on blackpolls are pronounced but not as emphatic as on the bay-breasted. Blackpolls have a more definite eyeline than bay-breasted, but the real clincher for a blackpoll is its yellow-orange feet! The bird may have dark legs but it always wears golden slippers. I have spent many frustrating minutes waiting for a blackpoll to show me its feet.

Notice the feet on both birds in the top photo, sticking out above the bander’s thumb.

Blackpoll warbler, Sept 2012 (photo by Marcy Cunkelman)
Blackpoll warbler, Sept 2022 (photo from Wikimedia Commons)

So next time you see a baypoll, check out its feet.

If you’d like to see birds up close during fall migration, visit Nick Liadis’ Bird Lab website and scroll down to the list of three banding locations — Hays Woods, Upper St. Clair and Twin Stupas in Butler County — with instructions for contacting him to set up an appointment.

Support Nick’s efforts with a donation at Bird Lab’s GoFundMe site.

p.s. In breeding plumage you’ll never confuse a bay-breasted with a blackpoll.

Bay-breasted warbler in breeding plumage, May 2009 (photo by Chuck Tague)
Blackpoll warbler in breeding plumage, May 2011 (photo by Chuck Tague)

We Like to Travel Together

Migration
Magnolia warbler and American restart (photos by Steve Gosser)

23 September 2024

This month warblers and thrushes are making long journeys from North America to Central and South America. Every week there’s a new cohort of species and some species pass through at the same time.

Lately I’ve noticed that when I find lots of American redstarts there are also many magnolia warblers. When I find Tennessee warblers there are often Nashville and black-throated green warblers as well.

Nashville, Tennessee and black-throated green warblers travel together (photos by Charity Kheshgi and Cris Hamilton)

Bird banders wondered about this phenomenon, too, so five banding stations including Powdermill Avian Research Center gathered 20+ years of banding data for a long term study of spring and fall migration. They grouped the banding data by season, by mist net and the date-time each bird was captured, and by species. When they examined which species were found together patterns emerged, published in their study Persistent species relationships characterize migrating bird communities across stopover sites and seasons.

Two species captured in the same net at the same time, over and over for a period of 20 years, indicates they are feeding together at stopover sites and are likely traveling together, too.

The study’s chart of fall migrants shows that American redstarts (AMRE) and magnolia warblers (MAWA) are often found together during fall migration (the thick red line). So are Tennessee warblers (TEWA), Nashville warblers (NAWA) and black-throated green warblers (BTNW). [See chart of 4-letter bird banding codes used in the diagram.]

Fall migration chart from Persistent species relationships characterize migrating bird communities across stopover sites and seasons

There’s even a correlation among thrushes. Notice the faint line between Swainson’s thrushes (SWTH) and gray-cheeked thrushes (GCTH), above.

Swainson’s and gray-cheeked thrushes (photos by Steve Gosser and Charity Kheshgi)

This fall I noticed that while many Swainson’s thrushes are traveling through southwestern Pennsylvania I’ve also seen a sprinkling of gray-checked thrushes. The line on the chart is probably faint because gray-cheeked thrushes are far less numerous than Swainson’s.

So who does this blackpoll warbler travel with? His traveling buddy is not on the chart but I can guess.

Blackpoll warbler, Sept 2012 (photo by Marcy Cunkelman)
Blackpoll warbler, Sept 2012 (photo by Marcy Cunkelman)

I’ll bet he travels with bay-breasted warblers. Can you say baypoll?

Read about the study in Audubon Magazine: A New Study Reveals Migration Isn’t a Solo Affair—It’s the Social Event of the Season.

See the full study in PNAS: Persistent species relationships characterize migrating bird communities across stopover sites and seasons.

Refueling on Migration

Migration, Plants & Fungi
Cape May warbler on Devil’s Walking Stick look-alike: Japanese angelica, 6 Sept 2023 (photo by Dave Brooke)

19 September 2024

During my recent journey in southern Spain I appreciated the opportunity to rest and refuel.

This month warblers are making their own long journey at night to Central and South America. When convenient they stop during the day in Pennsylvania to refuel on the fruit in our parks and gardens and on the insects that crawl on the fruit.

Seven years ago I wrote about what attracts them to stopover in our city parks. This vintage article is updated to reflect the real name of their favorite fruit in Frick Park.

Fruits On Migration

More Than a Hawk Watch

Migration, Spain, Andalusia, Travel
Black stork in flight, Algeria (photo from Wikimedia Commons)

12 September 2024: Day 6, Tarifa and birding at the Strait of Gibraltar, WINGS Spain in Autumn. Click here to see (generally) where I am today.

At U.S. hawk watches we track vultures, hawks, eagles, falcons and kites but rarely record other species at the official HawkCount.org. That is not the case at Tarifa where fall migration includes a total of 150,000 white storks (Ciconia ciconia) + black storks (Ciconia nigra).

This short video is the slow motion passage of four raptors. I am not sure of the first one but the others are two booted eagles (Hieraaetus pennatus) and an Egyptian vulture (Neophron percnopterus).

video embedded from Birding The Strait, Tarifa

Watch as huge numbers of soaring birds wait to cross the Strait. Notice the sound track! It is WINDY!

video embedded from Per Stensland on YouTube

Birding at the Strait is more than watching hawks.

p.s. We had a great morning on 10 September at Algarrobo hawk watch with thousands of hawks and eagles plus alpine & common swifts, four black storks, and 22 European bee-eaters.

Seen This Week: Warblers and Late Summer Flowers

Deer, Migration, Phenology, Plants & Fungi
Black-throated green warbler, Frick Park, 14 Aug 2024 (photo by Charity Kheshgi)

17 August 2024

This was a week of still-nesting swallows, pretty flowers, migrating warblers, and many, many deer in the city parks.

Moraine State Park, 11 August. Charity Kheshgi and I were surprised to see cliff swallows still nesting on 11 August at the Rt 528 Boat Launch area. Parents were feeding young at four to five nests.

Cliff swallows with young in nest, Moraine State Park, 11 Aug 2024 (photo by Charity Kheshgi)

Late summer flowers: Best photos this week are butter-and-eggs (non-native), spreading dogbane and blue vervain.

Butter and eggs, in the snapdragon family, Southside Riverfront Park, 12 August (photo by Kate St. John)
Spreading dogbane, Moraine State Park, 11 August 2024 (photo by Kate St. John)
Blue vervain, Southside Riverfront Park, 12 August (photo by Kate St. John)

Warblers at Frick Park: On 14 August Charity Kheshgi and I saw a good flock of warblers on Trough Trail. Blackburnians were still considered rare on the 14th (too early for them) but we found five! Here’s one eyeing a bug on Japanese angelica, a devil’s walking stick look-alike.

Blackburnian warbler, Frick Park, 14 Aug 2024 (photo by Charity Kheshgi)

We recognized distinctive plumage on each of the 5 Blackburnians. As if to prove there were so many, three posed in one shot.

3 Blackburnian warblers in one shot, Frick Park, 14 Aug 2024 (photo by Charity Kheshgi)

We also saw one immature chestnut-sided warbler hanging out in the flock.

Immature chestnut-sided warbler, Frick Park, 14 Aug 2024 (photo by Charity Kheshgi)

Deer: Schenley and Frick Parks, 14 and 16 August

It was a big week for deer in the city parks. I saw 10 in Frick on Wednesday, and 9 in Schenley on Friday. Of the 9, more than half were young or spotted fawns that were born this year. If my tally is representative, the Schenley deer population has doubled itself in just one year.

3 deer in Frick Park, 14 Aug 12024 (photo by Kate St. John)

I believe that the doe in this photo is shedding her summer fur (rusty color) to switch to her winter coat (gray-brown).

Spotted fawn with doe in Schenley, 16 Aug 12024 (photo by Kate St. John)
2 of the 9 deer seen in Schenley on 16 August 2024 (photo by Kate St. John)

Why are deer so easy to see in Schenley Park? Because there is no underbrush to hide them. There are so many deer that they ate all the underbrush. So there’s nowhere to hide.

p.s. The green grass in the photo is Japanese stiltgrass, a plant that deer don’t eat.