Category Archives: Migration

Swarms of Swallows

Tree swallow (photo from Wikimedia Commons)

12 August 2024

On Friday I wrote about a swarm of dragonflies. Today it’s a swarm of swallows.

On 31 July my sister watched more than two dozen tree swallows swarm over her yard in Tidewater Virginia. They were feasting on flying bugs for about 20 minutes, and then they were gone.

After they finish breeding, tree swallows (Tachycineta bicolor) gather in ever-growing flocks in July and August and begin their southward migration. In transit they seek out swarms of insects that may include true flies (Diptera), dragonflies and damselflies (Odonata).

Peak tree swallow migration occurs in early to mid-fall. I was at Cape Cod on 1 October 2017 when I witnessed a huge flock at West Dennis Beach. Abundant bugs attracted the tree swallows; abundant swallows attracted a falcon who captured one in his talons (top right of photo below).

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)

On 6 October 2021, Mike of Mike’s Nature Connection witnessed a similar flock on Cape Cod.

video embedded from Mike’s Nature Connection on YouTube

If you live in the Mississippi or Atlantic flyways, or at their wintering grounds in Florida or Louisiana, there’s still time to see swarms of tree swallows. Watch their annual movements in this weekly abundance animation from eBird.

Tree Swallow Weekly Abundance throughout its range (animation from eBird)

See this map for yourself at eBird Status and Trends > Tree Swallow > Weekly Abundance.

Roost Rings on Radar

Animation of base reflectivity showing roost rings, 2 Aug 2010, 6:10 AM to 7:17 AM (image from NWS Wilmington, OH)

16 September 2024

Our largest swallow, the purple martin (Progne subis), has a very short breeding period in North America. In Pennsylvania they arrive in late April and fledge young in mid July.

Purple martins at Bob Allnock’s in Portersville, PA, July 2016 (photo by Kate St. John)

As soon as the fledglings fly well, adults and young leave the nesting area and spend their nights in a communal roost.

Flocking begins as soon as nestlings fledge; birds of all ages assemble in roosts before fall departure. This may represent nonbreeding activity rather than a specific response to upcoming migration, because the species is highly social and flocks in large roosts throughout the overwintering period. 

Birds of the World: Purple Martin

Since the breeding period is earlier in the South, roosts in the Carolinas fill up in July and contain so many birds that their early morning departure can be seen on weather radar. This happened last week in Wilmington, North Carolina.

Facebook post from NWS Wilmington, NC on 12 July 2024

The same phenomenon happens at our latitude in August, as shown on radar in Wilmington, Ohio at top.

Learn more about purple martin roost rings in this article from Wilmington Ohio: Roosting Birds Detected By NWS Doppler Radar and this one from Wilmington, North Carolina: Purple Martin Roost Rings on Doppler Radar.

Unusual Visitor at Harrison Hills Park

7 July 2024

Yesterday morning Mike Fialkovich found a juvenile yellow-crowned night heron at Harrison Hills County Park. The bird was easy to find in a shallow creek by the Creekside Trail head at Overlook parking lot. By the end of the day 11 eBirders had stopped by to see this unusual visitor. Here’s the bird at dusk.

Yellow-crowned night herons (Nyctanassa violacea) specialize in eating crabs and crayfish, especially at night. They are usually found in salt marshes, forested wetlands, swamps and on coastal islands but they’re not worried about people and will show up on lawns in Florida.

As you can see from their range map, their stronghold is in Central and South America where they live year round. From there this southern visitor is expanding north.

Yellow-crowned night heron range map embedded from All About Birds

Adults explore out of range in the spring.

Yellow-crowned night heron, Cuba (photo from Wikimedia Commons)

Juveniles wander widely, especially in August and September. It seems too early for a youngster to wander up the Mississippi and Ohio Valleys as far as Harrison Hills but yellow-crowned night herons retain juvenile plumage for three years so this bird might not be as young as we think.

And he’s not the first unusual visitor. This yellow-crowned visited in Duquesne in August 2019 and stayed for a week. Maybe this year’s bird will stick around for a while.

Yellow-crowned night heron in Duquesne, PA, 18 Aug 2019 (photo by Amy Henrici)

Sounds Like A Bug

Clay-colored sparrow singing in Minnesota (photo by Lorie Shaull via Flickr Creative Commons license)

25 June 2024

Today I’m with a group of friends looking for a bird that sounds like a bug in Clarion County, PA.

We’re at Piney Tract, State Gamelands 330, where we expect to hear — and maybe see — grasshopper, field, Henslow’s and song sparrows.

Piney Tract, Clarion County, 1 June 2017 (photo by Kate St. John)
Piney Tract, Clarion County, 1 June 2017 (photo by Kate St. John)

Many grassland sparrows sound like bugs — hence the name “grasshopper” sparrow — but the bird we’re looking for is a clay-colored sparrow (Spizella pallida) who sounds like this:

This bird is special because he’s outside his normal range.

Range map of clay-colored sparrow (image from Wikimedia Commons)

Here’s one in North Dakota.

Clay-colored sparrow in North Dakota (photo from Wikimedia Commons)

Dan Mendenhall saw the bird last Friday so we stand a good chance of finding it. See Dan’s photo here.

Seen This Week

Blackpoll warbler, Presque Isle, 12 May 2024 (photo by Charity Kheshgi)

18 May 2024

Best birds this week were seen at Presque Isle State Park on Sunday 12 May while birding with Charity and Kaleem Kheshgi. At Leo’s Landing many of the birds were at eye level including this blackpoll warbler and the barn and bank swallows.

Barn and bank swallows, Presque Isle, 12 May 2024 (photo by Charity Kheshgi)

Even the treetop birds, like this yellow-throated vireo, cooperated for photographs.

Yellow-throated vireo, Presque Isle, 12 May 2024 (photo by Charity Kheshgi)

Was this redstart was looking askance at us? Or eyeing a bug?

American redstart, Presque Isle, 12 May 2024 (photo by Charity Kheshgi)

I had high hopes for the Bird Banding at Hays Woods on Wednesday 15 May but we were in for a surprise. No birds to band! Bummer. 🙁 This restart, banded earlier in the week, shows what we could have seen.

American redstart at Bird Lab banding (photo by Kate St. John)

After we left the banding station we had good looks at a scarlet tanager and found this Kentucky flat millipede (Apheloria virginiensis). It’s colored black and orange because it’s toxic.

  • It secretes cyanide compounds as a defense. Don’t touch it!
  • You might find one perched and dying on top of a twig. That’s because it can host the parasitic fungus Arthrophaga myriapodina which causes infected individuals to climb to an elevated spot before death (per Wikipedia). Eeeew.
Centipede Aphelosia virginiensis, Hays Woods, 15 May 2024 (photo by Kate St. John)

This week there were flowers in the tulip trees (Liriodendron) obscured by thick leaves. This flower came into view when a squirrel bit off the twig and didn’t retrieve the branch.

Tulip tree flower and leaves, 16 May 2024 (photo by Kate St. John)

Instead of rain on Wednesday we had a beautiful sunrise.

Sunrise 14 May 2024 (photo by Kate St. John)

To make up for no rain on Wednesday it’s pouring right now on Saturday.

Don’t Miss These Birds!

7 May 2024

If you’re wondering whether to go birding, don’t wait! Spring migration has been exceptionally good in the past few days migration. The slideshow, above, shows just a few of the 58 species Charity Kheshgi and I saw at Schenley and Frick Parks on Sunday 5 May.

The birds are here right now and they’re fairly easy to see despite the early leaf cover. They’re on the move. Don’t miss them. It’s time to get outdoors!

p.s. Did you notice that the first two birds in the slideshow are “Nashville” and “Tennessee” ?

(photos by Charity Kheshgi)

Best Warbler This Week

Brewster’s warbler, Tower Grove Park, May 2014 (photo from Wikimedia Commons)

4 May 2024

As I mentioned on Thursday morning, I spent a few days this week at Magee Marsh boardwalk where I experienced the quiet days before The Biggest Week in American Birding. On Thursday 2 May the weather was great, there were more birds to see, and there were 5 times as many people compared to Tuesday. That’s when I re-learned the advantages of birding with a (small) crowd.

I happened to be on a quiet section of the boardwalk when I noticed a crowd forming ahead. Many people were focusing binoculars and cameras at the spot where two guides were pointing and explaining a bird. I rushed over to find out what was up.

On my first look at the bird, I thought “golden-winged warbler” because of its yellow wing, yellow crown, and whitish chest (see example at top), but something wasn’t quite right. Word was spreading through the crowd that this was a Brewster’s warbler, the hybrid offspring of golden-winged x blue-winged warblers. Though not technically a species, for me it was a Life Bird.

The big difference between a Brewster’s and a golden-winged is that the Brewster’s looks pale with a white throat (not black) and a black eyeline (not a wider face patch). Here’s a side-by-side comparison of a male golden-winged warbler vs. a Brewster’s warbler.

Compare male golden-winged warbler to Brewster’s warbler hybrid (photos from Wikimedia Commons)

This diagram embedded from Cornell Lab’s All About Birds shows the warbler’s parents on the left and the Brewster’s in the top right corner. The parents can also produce another variation: a Lawrence’s warbler (bottom right) which I have never seen. Click on the caption to read about their genetics.

I left Magee Marsh yesterday morning while it was raining steadily so I missed the Brewster’s reappearance but my friend Kathy Saunders saw him on 3 May in the same place as the day before.

Yay! Best Bird!

(credits are in the captions)

In the Media: Peregrines, Spring Migration, and Birding

Downtown peregrine with bands, 14 April 2023 (photo by Jeff Cieslak)

3 May 2024

Usually there’s not much bird news in the media, but this was a big week so let’s catch up.

Peregrine falcon chick in Cathedral of Learning nest dies, CBS News, includes comments from Bob Mulvihill at the National Aviary. This is in addition to my report: Now There Are Only Two.

Flying high: Peregrine falcon population likely growing statewide, Pittsburgh Post-Gazette. Happy news continues on the peregrine’s success story in Pennsylvania.

Here come the early birds: Hummingbirds and warblers part of the first wave of spring migrants News on spring migration and recent hot weather.

And in case you missed it earlier this week, I appeared in a birding segment on KDKA’s Talk Pittsburgh with hosts Heather Abraham and Boaz Frankel at Frick Park.

video embedded from CBS Pittsburgh on YouTube

(credits are in the captions)

Starting Tomorrow: The Biggest Week for Birds

American restart singing (photo from Wikimedia Commons)

2 May 2024

Last weekend the headline in the Toledo Blade read:   Biggest Week  80,000 Birders Return on Friday. The Biggest Week in American Birding begins tomorrow at Maumee Bay Lodge in northwestern Ohio, drawing birders from around the world to see millions of migrating birds, especially warblers.

Normally I would be one of those 80,000 people but this year I didn’t have time for a trip next week so I’m here at Magee Marsh right now, 30 April to 3 May. As your advance scout I can tell you that the situation is different in the week before the Biggest one.

  • There were surprisingly few people here on Tuesday and Wednesday, 30 Apr and 1 May. There were few on the boardwalk, even fewer at Maumee Bay Lodge. That changed on Thursday 2 May when there were five times more people on the boardwalk. (The crowd began.)
  • Vendors for the festival started arriving on Wednesday.
  • Other than yellow-rumped and palm, there aren’t many warblers. Though the weather has been quite warm, overnight winds have been from the north, blowing off the lake. I’ve seen a small variety of warblers but only single birds and it takes effort to find them.
  • I miss the benefits of birding in a crowd. To find really good birds, I look for a crowd with their binoculars up and they help find the bird.
  • With so few birds (relative to the Biggest Week), a ruby-crowned kinglet drew a lot of attention.
  • This year: Only a short loop of the Maumee Bay Lodge Nature Center boardwalk is open. The majority is closed due to storm damage in June 2023 (shown here).

So the best time to see warblers in northwestern Ohio really is during the Biggest Week.

Biggest Week in American Birding logo, 2024

Meanwhile, in Pittsburgh migration is ahead of schedule and has been quite good. I haven’t seen any of the birds shown in the logo above in Ohio this week, but I’ve already seen the orange ones in southwestern PA — an American redstart and a Blackburnian warbler.

If I want to see the other two species — the Kirtland’s and mourning warblers — the best place will be northwestern Ohio during the Biggest Week.

(credits are in the captions)

Spring Update: Where Are We Now?

Oak tree in bloom with dangling pollen flowers (photo by Kate St. John)

1 May 2024

Since our last spring checkup six weeks ago, Pittsburgh has galloped into summer. Last weekend we had July-in-April weather with official highs of 83°F and even higher in town.

Pitt peregrine Carla felt the heat at 10am on 29 April as she shaded her chicks and gular fluttered (panted) to cool herself off.

It’s hot at the Pitt peregrine nest, Carla shades the chicks, 29 April 2024, 10am (photo from the National Aviary falconcam at Univ of Pittsburgh)

Pittsburgh is not alone. In a wide swath of the U.S. from Iowa to New York spring was 20+ days early this year. In Pittsburgh nearly half of April was more than 10°F above normal while we had only one cold day at 12°F below normal.

U.S. Daily Spring Index Leaf Anomaly, 1 May 2024 (map generated by USANPN Visualization Tool)

So what temperature should we expect if we’re only 20 days ahead of schedule? April 29th ought to have been like a normal 19 May but it was way beyond that.

The heat prompted the trees to leaf out early and flowers to bloom ahead of schedule. Maples and buckeyes are in full leaf now and our oaks are at flower+leaf stage as shown at top. The leaves are hosting food for birds in the form of tiny caterpillars, so …

Migratory birds are taking advantage of the south winds and early leaf out. Since 27 April we’ve seen our first scarlet tanagers, rose-breasted grosbeaks, Baltimore orioles, indigo buntings and warblers.

Charity Kheshgi has been documenting our good luck with warblers at Frick Park. Notice the size of the leaves in her photos!

p.s. And where am I? Right now I’m at Magee Marsh a week ahead of The Biggest Week in American Birding. I don’t expect to see the swarms of migratory birds that will be here next week (I’m leaving on 3 May) but I’ll learn what happens before the people show up and why everyone waits until next week. 😉

(credits are in the captions)