Category Archives: Migration

Most Spectacular Raptor Migration in the World

Amur Falcon, male in South Africa (photo from Wikimedia Commons)

27 January 2024: Day 9, Chobe National Park, Botswana — Road Scholar Southern Africa Birding Safari. Click here to see (generally) where I am today.

Amur falcons (Falco amurensis) breed in Siberia and northern China and travel 22,000 km (13,670 mi) each fall to southern Africa. Not only is their migration the longest of all the raptors but when they stopover in autumn to refuel in Nagaland, India their flock can number half a million birds. Right now they’re in southern Africa where I hope to see them.

Amur falcons are insectivores who, on migration, capture flying insects to eat in mid air.

Male Amur falcon eating an insect in flight in South Africa (photo from Wikimedia Commons)

They time their migration and choose a route to take advantage of insect swarms.

  • In northeastern India winged adult termites swarm in autumn in Nagaland.
  • Over the Arabian Sea dragonflies migrate in the fall from India to Africa.
  • In southern Africa, December to March rains spawn swarms of termites, locusts, ants and beetles.
Range map and migration route of Amur falcon (image from Wikimedia Commons, annotated)

Amur falcons are present from October to December near the Nagaland village of Pangti where they fatten up on termites before continuing their journey. There are hundreds of thousands of falcons in the air at once.

video embedded from Ace Ventura on YouTube

Their abundance led to near tragedy, however. Until the practice ended in 2012, Nagaland hunters caught tens of thousands of falcons per day in fishing nets hung from the trees. Each year they killed 250,000 Amur falcons to sell as meat for mere pennies. They thought the falcons would never disappear.

The killing ended abruptly when journalist Bano Haralu returned to her homeland, witnessed the destruction, and got a hunting ban placed in November 2012. More importantly, she and her colleagues taught the villagers, and especially the children, the importance of the falcons and a way forward through ecotourism. It was a stunning turnaround and a credit to the people of Nagaland.

Amur falcons gather at Pangti, Nagaland, India on migration (photo from Wikimedia Commons)

In 2018 Scott Weidensaul went to Pangti to see the birds and tell their amazing story in A Galaxy Of Falcons: Witnessing The Amur Falcon’s Massive Migration Flocks. Birders flocked to the spectacle last fall.

UPDATE on 29 January 2024: I was fortunate to see a female Amur falcon in Namibia today, swooping for insects near the Chobe River. (These photos are from Wikimedia.)

Female Amur falcon, South Africa (photo from Wikimedia Commons)

For more information see:

Will Pittsburgh Get Cold Enough for Rare Gulls Next Week?

Watching gulls at the Point, Pittsburgh, PA Jan 31, 2015 (photo by Tim Vechter)
Watching gulls at the Point, Pittsburgh, PA, 31 Jan 2015 (photo by Tim Vechter)

11 January 2024

Only a few days ago I was lamenting that we weren’t having a snowy winter, neither snow nor snowy owls. Well, be careful what you ask for! A few days of bitter cold are coming to Pittsburgh next week. If Lake Erie freezes, arctic gulls will fly south to find open water on the rivers. The photo above shows some cold and happy birders looking at rare gulls at the Point in January 2015.

So what are the chances this will happen next week?

As of this morning, the forecasted low temperature for dawn on Wednesday 17 January is 9°F. This map for next Monday sure looks like we’re in a “polar vortex.” Cold, right?

Low temperature forecast for Monday 15 January 2024 as of 11 Jan ( from the NWS)

But will it be cold long enough to freeze Lake Erie and send the gulls south? Probably not. The eastern Great Lakes ice map as of yesterday, 10 Jan 2024, shows nearly 100% open water (white).

Eastern Great Lakes Ice Chart as of 10 Jan 2024 (map from North American Ice Service)

There’s not even a hint of ice (blue) on most of Lake Erie and the Great Lakes ice-to-date graph for winter 2023-24 indicates that ice is at a near record low. There’s a lot of cooling off to do before the lakes will freeze.

So next week I’ll have to wear my Minnesota gear to go outdoors but it’s unlikely there will be any unusual birds out there. Will I want to go out in 9°F anyway? I’ll have to wait and see.

(credits are in the cations)

Eats Fruit and Leaves

American robin eating fruit in early winter, Toronto (photo from Wikimedia Commons)

23 December 2023

Early this week a big flock of American robins came to my neighborhood, ate all the fruit they could find, and left.

On Monday morning, 18 December, they were frantically eating this pyracantha fruit outside my window. At one point I counted 45 but they were moving so fast I think there were more.

Pyracantha full of fruit, 23 Nov 2023 (photo by Kate St. John)

The birds were frantic because they knew bad weather was coming. In mid afternoon it snowed.

Snow flurries 18 December 2023, 3pm (photo by Kate St. John)

The next morning the fruit was gone and so were the robins.

Sam pyracantha with no more fruit, 19 December 2023 (photo by Kate St. John)

American robins are still in Pittsburgh but they’re feasting in other locations. When the fruit is gone and the ground is frozen, the robins will leave.

p.s. Today’s title reminds me of the 2006 bestselling book on punctuation by Lynne Truss called Eats, Shoots and Leaves. The comma in her book title is really important. Did the panda eat, shoot a gun, and then leave? Or did the panda eat two things — shoots and leaves? … In the case of today’s blog title: Robins don’t eat leaves. They eat fruit and leave the neighborhood.

White Stork Transmitter Goes Roaming in Sudan

White stork flock in Africa (photo from Wikimedia Commons)

20 October 2023

Most people who find discarded bird tracking technology don’t know what they’re looking at and even when they do they don’t usually repurpose it. But every once in a while a transmitter goes roaming.

White storks (Ciconia ciconia) that breed in Poland migrate to eastern and southern Africa for the winter. For some, their final destination is the Blue Nile River valley, circled in yellow on the map below.

White stork migration paths (map from Wikimedia Commons) Blue Nile Valley in Sudan is circled in yellow

In April 2017 a white stork in Poland, nicknamed Kajtka, was tagged with a transmitter containing a mobile SIM card.

SIM card T–Mobile Poland (image from Wikimedia Commons)

That autumn she flew to the Blue Nile River valley in Sudan where she became mysteriously inactive. Eventually she stopped moving altogether and had either died or the transmitter fell off. Researchers couldn’t figure out what happened until they got the phone bill.

Questions were raised when Kajtka lingered in the area for more than eight weeks, only roaming around 25 km [15 miles] in various directions.

In 2018, the mystery was solved when EcoLogic Group received a phone bill for 10,000 Polish zloty, the equivalent of £2,064 [$2,500]. Someone had picked up the tracker in Sudan and taken the opportunity to make 20 hours of phone calls using the SIM card.

White Stork transmitter racks up massive phone bill

Fortunately for cash-starved bird research this sort of episode is rare.

If Kajtka had survived she would have joined her fellow white storks moving north in March, perhaps with a stopover in the Hula Valley shown below. Gorgeous!

video from The Wildlife Channel on YouTube

(credits are in the captions)

Hundreds of Grackles in the Trees

Common grackle flock moving through the trees, Patuxent Research Refuge, Nov 2021 (photo from Wikimedia Commons)

18 October 2023

This month a flock of 100 to 200 common grackles has been hanging out at Frick Park, chattering in the trees and swirling in a dense flock whenever they’re disturbed. This is typical fall behavior for grackles and blackbirds but I wondered why they picked the park.

According to Birds of the World, common grackles (Quiscalus quiscula) are not very territorial during the breeding season and drop all rivalry in fall and winter. On migration and at overwintering sites they prefer to roost and feed in huge flocks, sometimes mixed with other blackbirds and some robins.

Common grackles roost near plentiful food but they don’t require wild places. Urban roosts are often favored on tree-lined streets or in parks. Their fall roosts in New Jersey can contain 3,000-500,000 birds (of which grackles comprise 33%).

This flock at Patuxent in Maryland looks to be 100% grackles.

Common grackle flock on the ground at Patuxent Research Refuge, Nov 2021 (photo from Wikimedia Commons)
Common grackle flock starting to swirl up at Patuxent Research Refuge, Nov 2021 (photo from Wikimedia Commons)
Common grackle flock mostly flown away at Patuxent Research Refuge, Nov 2021 (photo from Wikimedia Commons)

Get To Know Nature in New Jersey shows what it’s like to be in the forest with hundreds of grackles.

video by Get To Know Nature on YouTube

The huge grackle flocks probably won’t stay in southwestern PA for the winter. By December they are further south, as shown on the eBird Dec-Feb map below.

Common grackle sightings, Dec-Feb, past 10 years (retrieved from eBird on 3 Mar 2022)

But for now we have hundreds of grackles in the trees.

(credits are in the captions; click on the captions to see the originals)

Birds Take a Taxi to Correct For Climate Change

Male European pied flycatcher (photo from Wikimedia Commons)

9 October 2023

Birds like the European pied flycatcher (Ficedula hypoleuca) that winter in the tropics and southern hemisphere do not use weather clues to tell them when to fly north in the spring. Instead they cue on changing day length and return at the same time every year. But as Earth’s climate changes, spring comes weeks earlier than it used to and their migration timing is out of sync. Scientists in the Netherlands decided to give a few lucky birds a lift (a Lyft?) to Sweden and it made all the difference.

Pied flycatchers prefer to nest in or near oak trees where their nesting season is timed to correspond with the peak of caterpillar season. Unfortunately, spring is two weeks earlier now in the Netherlands, pied flycatchers arrive too late and have locally experienced a 90% decline.

Female European pied flycatcher carrying caterpillars (photo from Wikimedia Commons)

The old timing of Netherlands’ spring is now found in southern Sweden so scientists at University of Groningen in the Netherlands and Sweden’s Lund University decided to see what would happen to migration and nesting success if a few pied flycatchers were transported (by car!) from the Netherlands to suitable habitat in Sweden.

Anthropocene Magazine reports, “For three springs, starting in 2017, scientists from the University of Groningen in the Netherlands and Sweden’s Lund University caught newly-arrived Dutch female pied flycatchers and drove them by car to a nesting spot 570 kilometers (354 miles) away in southern Sweden that was already home to other pied flycatchers.”

Range of European pied flycatcher (map from Wikimedia Commons)

The experiment was wonderfully successful. The Netherlands’ females were in sync with the food supply and were twice as prolific as their Swedish counterparts who were locally out of sync. After spending the winter in Africa the former-Netherlands females returned to Sweden and so did their offspring!

Later the research team proved that migration timing is genetically inherited in European pied flycatchers by taxiing a few eggs laid in the Netherlands to Swedish nests. Those offspring returned to Sweden the following spring on the Netherlands timing.

Taxi service cannot be the answer to out of sync migration but birds are adapting on their own. During the study, banding still continued at Netherlands nests and some of those youngsters were found nesting in Germany, halfway to Sweden. They flew there on their own.

Read more about the taxi ride experiment in Anthropocene Magazine: For some birds, a “taxi” helps recalibrate out-of-sync migrations.

(photos and map from Wikimedia Commons; click on the captions to see the originals)

Do Blackpolls Sleep in Flight Over the Atlantic?

Blackpoll warbler in PA, Oct 2020 (photo from Wikimedia Commons)

5 October 2023

Some birds are champion fliers, staying airborne for days or months at a time. Scientists wondered if birds sleep in flight and proved that they do in a 2016 study of great frigatebirds, finding that the birds either “sleep with one half of their brains active, or with both hemispheres shut down at the same time.” Read more in this vintage article, Asleep in Flight.

Blackpoll warblers (Setophaga striata) are also champion fliers making a non-stop fall migration over the Atlantic Ocean of 1,900 miles in 72 to 88 hours. Traveling at 27 mph, they launch from the east coast between Nova Scotia and South Carolina and fly to their only stopover in Puerto Rico or Hispaniola (Haiti & Dominican Republic), then on to northern South America.

The blackpoll’s transoceanic path was proven in a 2015 study by Bill DeLuca and the Vermont Center for Ecostudies. VCE writes:

Bill DeLuca (Northeast Climate Science Center) and VCE solved this great modern-day avian mystery. Using light-level geolocators attached to Blackpoll Warblers in Vermont and Nova Scotia, DeLuca and colleagues documented the longest distance non-stop overwater flights ever recorded for a migratory songbird. During October, Blackpoll Warblers initiate a ~3-day non-stop transoceanic flight of ~2500 km from the north Atlantic Coast to Hispaniola and Puerto Rico. Radar data show migrating songbirds fly at 2,600 to 20,000 feet while making this journey. After a few weeks, they fly onto Columbia or Venezuela where they overwinter. Their spring migration route takes them over Cuba to Florida, where they journey up the eastern US seaboard to reach their breeding grounds in late May.

Vermont Center for Ecostudies: Blackpoll Warbler

Notice in this eBird abundance map for the week of 2 Nov that blackpolls are:

  • bunched up on the East Coast from Massachusetts to North Carolina
  • at a stopover on Puerto Rico and
  • early migrants have already arrived in South America.
Blackpoll warbler weekly abundance map, week of 2 Nov 2007-2021 (map from eBird Status and Trends)

Watch them throughout the year in this eBird abundance animation.

Blackpoll warbler weekly abundance map (animation from eBird Status and Trends)

Of course I wondered if blackpoll warblers sleep in flight during their 3 day transoceanic trip, but we won’t find out any time soon. Blackpolls are way too small to wear the sleep monitoring gear used on the great frigatebird.

(photo from Wikimedia Commons, maps from eBird Weekly Abundance; click on the captions to see the originals)

ebird species migration weekly abundance trends

Yesterday at Hays Woods Bird Banding

Hermit thrush banded at Bird Lab, Hays Woods, 3 Oct 2023 (photo by Jared Miller)

4 October 2023

Joe, Sam and Jared joined me yesterday morning on an adventure to see Bird Lab at Hays Woods. The weather was perfect as we walked more than half a mile to the banding station. There we found Nick Liadis and his assistants about to do the second net-check of the day.

The mist nets that capture songbirds are set up in “alleys” of vegetation where birds might fly across. If a bird doesn’t see the net and tries to fly through, it falls into the pocket of extra netting material where it waits to be retrieved. Banders check the nets every half hour.

Bird banding mist net at Hays Woods, 7 Sep 2022 (photo by Kate St. John)

Captured birds are brought back to the banding table in cloth bags to keep them calm. Our group watched as Nick prepared to band three birds from the recent net check.

Bird Lab at Hays Woods: 3 workers (orange vests) and three observers, 3 Oct 2023 (photo by Kate St. John)

Each bag contains a surprise. The first was a recaptured Cape May warbler (Setophaga tigrina), originally banded on 20 Sep when it weighed 10.9g. Yesterday it weighed 13.8g for a gain equivalent to the weight of a ruby-throated hummingbird. Such a small bird in Nick’s hand, below.

Nick Liadis holds a Cape May warbler recaptured at Hays Woods on 3 Oct, first banded on 20 Sept 2023 (photo by Kate St. John)

It was the second Cape May warbler recapture this fall. The first one increased its weight by 50% in two weeks. About the first one, Nick wrote:

A cool recapture from my Hays Woods banding station! This Cape May Warbler was banded on 9/13 and we captured her again two weeks later. She originally weighed 11.6g and today weighs 15.4g. Interesting to see how long some of these birds hang around. I’d imagine she’ll be on her way very soon.

— Nick Liadis message, 27 Sep 2023

Next on the agenda was a hatch year (meaning “hatched this year”) male black-throated blue warbler (Setophaga caerulescens). His color was blue, but not vibrantly so, and his throat had tiny white flecks on it. I had seen a dull bird like this in Frick Park last week and didn’t realize that meant he was young.

BirdLab at Hays Woods: Hatch Year male black-throated blue warbler in partial adult plumage, 3 Oct 2023 (photo by Jared Miller)

At each successive net check new species showed up.

The hatch year hermit thrush (Catharus guttatus) shown at top was a sign that the mix of migrant species is changing. The insect eaters are nearly gone while the fruit and nuts migrants have arrived (*see note).

The hatch year female house finch, below, was probably born at Hays Woods. Many house finches in the eastern U.S. are permanent residents. Perhaps she will be, too.

BirdLab at Hays Woods: Hatch Year female house finch, 3 Oct 2023 (photo by Kate St. John)

An ovenbird (Seiurus aurocapilla) is always nice to see up close and I had no trouble identifying it because it showed its striped crown. I saw one in the hand at Bird Lab last year.

BirdLab at Hays Woods: Ovenbird, 3 Oct 2023 (photo by Kate St. John)

By 10:00am we’d been there an hour, it was getting hot (the high yesterday was 85°F!) and the birds were less active. Three of us hiked to the overlook and returned for one more net-check. This time only one bird was captured, a hatch year house wren (Troglodytes aedon) that Nick had banded on 9 August. This bird has spent the last two months foraging at Hays Woods and soon it will migrate to Central or South America.

BirdLab at Hays Woods: House wren, 3 Oct 2023 (photo by Jared Miller)

We left Bird Lab and headed back to the parking lot where the fleet of enormous dump trucks, seen at 8:30am, were still shuttling dirt to/from Duquesne Light’s dirt road. Duquesne Light is building an access path to the cliff edge where two transmission towers need to be replaced and moved away from the landslide zone.

Thanks to Jared Miller for sharing his photos, shown above.

Bonus Bird: After the banding, a rare bird at Duck Hollow:

At 10:30am I received an alert that a migrating American avocet (Recurvirostra americana) was hanging out at Duck Hollow. Avocets in Allegheny County are One Day Wonders. I had never seen one here because I waited a day to go see them. So I made the short trip from Hays Woods to Duck Hollow and digiscoped this lousy picture. The light was too bright to see its faint orange color but you get the idea.

American avocet at Duck Hollow, 3 Oct 2023 (photo by Kate St. John)

p.s. (*) Two of the phases of fall migration: ** Insect eaters such as warblers, flycatchers, swifts and swallows migrate through in September because the bug population is going to die when cold weather hits. ** Fruit and nut eaters, including thrushes and sparrows, pass through in October.

(photos by Jared Miller and Kate St. John)

Undertail Tells The Tale

Magnolia warbler in fall, Sept 2018 (photo by Dave Brooke)

19 September 2023

Right now warbler migration is at its autumn peak in southwestern Pennsylvania but, as usual, the birds are hard to identify. Their fall plumage is dull and confusing, they move fast so we never get a good look at them, and we don’t get much practice because many of them are here only in September. And then they’re gone.

This year it dawned on me that the magnolia warbler (Setophaga magnolia) is super-easy to identify if all you see is its butt, as shown at top and below.

Magnolia warbler shows its undertail, May 2019 (photo from Wikimedia Commons)

The “maggie” has a unique pattern on its undertail, easy to see on the free Visual Finders PDF, downloaded from The Warbler Guide. I’ve highlighted the magnolia warbler on this screenshot of Page 15.

Visual Finders Download, Eastern Undertails page from The Warbler Guide I have highlighted the Magnolia tail

Note that the magnolia warbler is the only warbler with a white belly, white undertail coverts, white undertail and a large black straight-edged tip on the tail. It looks as if this warbler was dipped tail first in black paint.

Magnolia warbler excerpt from Visual Finders Download, Eastern Undertails page from The Warbler Guide

On some juveniles the tip is dark gray but the pattern is the same.

So this view is the best way to identify a magnolia warbler.

Underside of a Spring plumage magnolia warbler (photo from Wikimedia Commons)

The undertail tells the tale!

Download Stephenson & Whittle’s free Visual Finders PDF at The Warbler Guide.

(photos by Dave Brooke, diagrams from The Warbler Guide free download)

I highly recommend the 560-page The Warbler Guide by Tom Stephenson and Scott Whittle which I use at home after noting the warbler’s key features in the field. In my opinion the book is indispensable if you take photographs.

Flying With The Birds

Ultralight leads whooping cranes on migration (photo from Wikimedia Commons)

15 September 2023

For nearly 30 years ultralights have been used to establish safe migration routes for endangered geese and cranes as they are reintroduced to the wild.

In 1993 ultralight pioneer Bill Lishman, along with Joe Duff, conducted the first ever human-led bird migration by guiding a small flock of young Canada geese from Ontario to Virginia. His experiment proved that young geese imprinted on an ultralight will follow the aircraft and learn the migration route. After leading the birds just once, in one direction, the geese knew the route and returned on their own in the spring.

Christian “Birdman” Moullec was the first to do it in Europe when he guided lesser white-fronted geese (Anser erythropus) from their future breeding grounds in Sweden to new wintering grounds in Germany in 1999. He has since led red-breasted geese (Branta ruficollis) and many other species.

Red-breasted goose and lesser white-fronted goose (photos from Wikimedia Commons)

Nowadays, to raise money for his conservation efforts, Christian Moullec offers tourists ultralight flights with the birds.

Learn what it’s like to take one of his flights in: A Man, a Tiny Aircraft, and a Flock of Geese: Flying Among Birds in France. See the magic in this video from National Geographic.

video embedded from National Geographic on YouTube

Visit Moullec’s website at Fly With Birds.

(credits are in the captions)