Category Archives: Migration

Dragonflies Are Migrating

Insects, Migration
  • Common green darner, Virginia (photo from Wikimedia)

10 September 2023

On the evening of Friday 8 September, Marianne Atkinson noticed hundreds of dragonflies patrolling a field near her house in Dubois, PA. Other folks as much as 20 miles away were commenting on the same thing and posting videos online. What were these bugs up to? Marianne sent me her video …

video by Marianne Atkinson

… and this Facebook post from the McKean County Conservation District explaining the phenomenon. Dragonflies are migrating.

The green darner is the most common migratory dragonfly in Pennsylvania but is only one of 16 migratory species in North America. The five main migrants are pictured in the slideshow at top and listed below from Donna L Long’s website.

Green darners have a multi-generational migration. The individuals we see flying south right now will not return but will be the grandparents of those who journey north next spring.

Recent research has indicated that the annual life cycle of green darner (Anax junius) is likely composed of at least three different generations. The first generation emerges in the southern end of its range in early spring and migrates northwards through spring and summer. The second generation emerges in the northern end of its range in summer and migrates southwards in fall. The third generation occurs in the south during the winter and does not migrate. 

— Wikipedia: Green Darner

When dragonflies migrate during the day in Pennsylvania they follow the same flight paths and fly on the same prime migration days as the hawks. I often see dragonflies at hawk watches where I’m glad they’re eating mosquitos and flying ants on the wing.

Green darners seem to go far but for real long distance the global skimmer wins the prize, migrating from India to Africa across the Indian Ocean! It also occurs in North America.

(video from RoundGlass Sustain on YouTube)

p.s. There are 7,000 species of dragonflies on Earth. Only 25-50 species migrate, making this a very unusual feat.

(photos from Wikimedia Commons, video by Marianne Atkinson and an embed from Youtube)

Thousands Glide To Africa

Migration, Water and Shore
White stork in flight (photo from Wikimedia Commons)

6 September 2023

The migration spectacle at the Strait of Gibraltar is still underway as thousands of birds stretch their wings and fly to Africa. They can see their goal from the European side but sometimes the wind is a brutal wall that prevents their crossing. On 4 September the wind was right and they didn’t have to flap. Thousands glided south to Morocco.

Among the flocks were hundreds of white storks (Ciconia ciconia), seen in this tweet from Inglorious Bustards.

The storks making the crossing had nested in Western Europe and are heading for Sub-Saharan Africa for the winter.

Range map and flyways of the white stork (map from Wikimedia Commons)

Fifty years ago white storks were extinct in most of Western Europe and this spectacle at the Straits died with the absent birds. Reintroduction programs in the late 20th century brought them back to a growing population of now 224,000 to 247,000 European white storks.

For those who lived through the lean years, their tears at the Straits are tears of joy.

(credits are in the captions including links to the sources)

Sleeping On Migration

Bird Behavior, Migration
Sparrow asleep in New Mexico (photo by Larry Lamsa via Flickr Creative Commons license)

31 August 2023

Migration is exhausting work and since warblers migrate at night, they must rest and refuel during the day. Food and good cover are both essential at their rest stops. Sleeping is a dangerous activity where predators lurk.

A study published in Current Biology, August 2019, revealed one way that migrating warblers manage these dangers and demands: They adjust their sleep postures depending on their physical condition and physiological needs. Plump, well-muscled birds tend to sleep with their heads held upright, while scrawnier warblers tuck their heads into their feathers, a posture that makes them more vulnerable to predation but helps them conserve their much needed energy.

— New York Times: Some Migratory Birds Sleep Better Than Others, August 2019

Fit warblers can afford to be vigilant. They puff up and sleep in a watchful posture, sometimes out in the open. This makes them ready to escape at a moment’s notice.

Sardinian warbler asleep on a branch (photo from Wikimedia Commons)

Exhausted warblers hide in thickets and tuck their heads under their wings. This provides much needed rest and protects against heat loss but makes them vulnerable to predators. Interestingly, these same birds sleep less than those in good condition because they have to spend more time foraging.

Bird sleeping with head tucked under wing (photo from Wikimedia Commons)

Some long distance migrants, such as the ocean-going great frigatebird, can sleep in flight.

Great frigatebird in flight (photo from Wikimedia Commons)

A 2016 study equipped great frigatebirds (Fregata minor) with EEG equipment and proved that they sleep while flying though they get less sleep in the air than on land. Read more in this vintage article.

Asleep In Flight

It would be nice to safely sleep while doing other things. Yawn! I’m ready right now.

(photos from Wikimedia Commons, see links in the captions)

Olive-Sided Flycatchers Stop to Refuel

Migration
Olive-sided flycatcher (photo from Wikimedia Commons)

29 August 2023

Olive-sided flycatchers (Contopus cooperi) are rare birds in Pittsburgh. Not only have they declined 78% since 1970, but they are only present on migration and then just one or two per season. When three individuals were found on the same day, Friday 25 August, in Allegheny County it was rare indeed. These three were not the same bird:

  • Sewickley Heights Borough Park at 8:20am, seen recently on Monday 28 Aug
  • Hartwood Acres, Saxonburg Fields at 10:50am
  • Homewood Cemetery at noon

Though olive-sided flycatchers nest from Alaska to Newfoundland and southward into the Cascades and Rockies, not much is known of their migration routes. In the fall the eastern birds generally flow westward within Canada, then hang a left at Minnesota and migrate through the Great Plains and eastern Rockies. You can see their relative abundance from the 3rd week of August through the 3rd week of October in this slide show.

Olive-sided flycatcher weekly relative abundance from eBird Status and Trends

Alaska’s breeding olive-sided flycatchers are declining rapidly and have one of the longest migrations of any flycatcher — from Alaska to Peru. Migratory stopover sites are very important for their survival but nobody knew where they went so a study team, headed by Julie C. Hagelin, decided to track the birds’ migration by catching them in mist nets and attaching geolocator backpacks.

What they discovered when the birds returned is that Alaskan breeders fan out across the Rockies on their way south, some as far east as Texas, before they head through Mexico to South America. They also found 13 important stopover sites that are critical to the birds’ survival on migration. Their favorite spots are slightly different in Central America in fall versus spring. Two of the 13 sites are in the U.S. Cascade Mountains. All the sites are on these maps.

(illustration from DeGruyter: Revealing migratory path, important stopovers
and non-breeding areas of a boreal songbird in
steep decline)

Pittsburgh never figures heavily in the olive-sided flycatcher’s travel agenda though this year we seemed to be an attractive stopover. Our birds probably come from breeding sites in eastern Canada.

Are our olive-sided flycatchers stopping at the same places in Central America as the Alaskan group? We won’t know until some runs a similar study in eastern Canada.

(photo from Wikimedia Commons, abundance maps from eBird, stopover maps from DeGruyter; origin links are in the captions)

Massive Migration

Migration
White stork flock migrating over Israel, Sept 2007 (photo from Wikimedia Commons)

19 August 2023

Fall migration is underway across the Northern Hemisphere. Some birds migrate alone or in small flocks that don’t attract much attention. Others gather in such massive flocks that they are hard to miss.

At pinch points along their migration routes from Europe to Africa, white storks (Ciconia ciconia) travel in very large flocks like the kettles of broad-winged hawks in North America. Two such pinch points are in the airspace over Israel, above, and at the Strait of Gibraltar.

In this short video white storks are about to cross the Straits from Spain to Morocco but hit a wall in the air — the levant wind blowing from the east — so they wheel back. They did not leave Spain that day.

In North America semipalmated sandpipers (Calidris pusilla) migrate in massive numbers from their breeding grounds in the Arctic to the shores of South America.

Semi-palmated sandpipers on migration in Maine (photo from Wikimedia Commons)

At the Bay of Fundy the flocks can number in the hundreds of thousands in August and early September.

(photos from Wikimedia Commons; tweets embedded)

A Limpkin Irruption?

Migration, Water and Shore
Limpkin at Moraine State Park, 16 July 2023 (photo by Steve Gosser)

17 August 2023

After a limpkin was discovered yesterday afternoon in a small cove at Moraine State Park (first ever in Butler County!) western PA’s birding world spun on its axis and quickly went to find it. Many saw the bird yesterday including Steve Gosser who shared his photo above.

Limpkins (Aramus guarauna) are very, very rare this far north. Primarily from South America, these mussel and snail-eating wading birds have extended their range only to Florida where they live year round.

Limpkin range map from Wikimedia Commons

So what is a limpkin doing here? And not just “here.” A limpkin showed up at Middle Creek Wildlife Management Area last month and was still there last weekend. Two limpkins were in opposite corners of Ohio.

In fact, limpkins have been doing this crazy Northern Summer Visit thing for a long time but it appears they’ve ramped up since 2016. On 8 July 2023 Tim Healy posted a map of Limpkin Firsts in North America at the ABA Rare Bird Alert on Facebook. (The color descriptors are for the map.)
“Hot Limpkin Summer forever! Keep it going! Who’s next?
Green: home base
Blue: historical first records
Orange: 2016-2022 first records
Red: 2023 first records”

ABA Rare Bird Alert on Facebook: 8 July 2023, Tim Healy

This eBird map shows where they’ve been in 2023 up until 16 August. (I’ve marked the Butler County sighting as a red asterisk.)

eBird map of limpkin sightings in 2023 up until 16 August 2023

Is this an irruption of limpkins similar to the winter irruption of snowy owls? Maybe…

Young night-herons often do an out-of-range dispersal at the end of the breeding season when first-year birds explore to the north, then head home or die during their adventure. Perhaps limpkins are doing it, too. Perhaps they’ve had so much breeding success that there are extra limpkins to try it. (This family of 5 was photographed in Florida in 2014.)

Adult limpkin with 4 young, Winter Haven, Florida, 2014 (photo from Wikimedia Commons)

It will take some research to know the answer. The limpkins aren’t saying.

(photos by Steve Gosser and from Wikimedia Commons, maps from Wikimedia and eBird)

Migration! Arrivals & Departures This Week

Migration
Ruby-throated hummingbird, Annandale, NJ, 5 Sept 2012 (photo by Ellen & Tony via Flickr Creative Commons license)

14 August 2023

A lot of us think that fall migration doesn’t start until the end of August, but guess what? BirdCast resumed migration predictions on 1 August and their regional lists of Species On The Move show an influx of 10 noticeable species this week while five have already left, or are about to. Don’t wait to go birding. Check BirdCast tools to find out why.

Species On The Move uses two decades of eBird data to calculate movement from start to finish within four regions: Upper Midwest & Northeast, Gulf Coast & Southeast, Great Plains, and West. Of course they list First Arrival, Peak, and Last Departure but my favorite markers are:

  • Noticeability: *** Three asterisks mean we’re really likely to notice this species.
  • Rapid Migrant Influx: A few may be here already but numbers increase rapidly on this date.
  • Rapid Departure: Numbers drop quickly on this date though a few will linger.

The tables are grouped by region with Pittsburgh in the heart of BirdCast’s Upper Midwest & Northeast region. These dates are estimates but they’re good ones. Let’s take a look at who left and who’s coming soon.

Noticable Departures: Who Just Left?

Orchard oriole singing at Frick Park, 26 April 2023 (photo by Charity Kheshgi)

Have you noticed that orchard orioles, northern rough-winged swallows and willow flycatchers are basically gone? They started leaving in July, then rapidly departed in the first week of August. Yellow warblers and purple martins are not far behind. They’ll leave this week.

The screenshot below is a quick summary of rapid departures as of 13 August 2023. It shows:

  • Upper Midwest and Northeast region
  • Pared down to Noticeable birds (*** or **)
  • Sorted by Rapid Migrant Departure date
  • Not including some goodies such as Louisiana waterthrush, alder flycatcher and least bittern. (They’re on the website but not “Noticeable” for my pared-down screenshot.)
pared-down screenshot of BirdCast Species On The Move, noticeable Last Departures, Upper Midwest & Northeast

Noticeable Arrivals: What Rapid Influx will we see this week?

Immature ruby-throated hummingbird (photo from Wikimedia Commons)

If you haven’t seen them already ruby-throated hummingbirds will make a rapid influx today, 14 August.

The larger region will see increased numbers of common nighthawks and Canada Warblers but in Pittsburgh it’s usually the last week of August.

Common nighthawk photo by Chuck Tague; Canada warbler photo by Kuldeep Singh

Here’s a quick summary of Beginning Arrivals as of 13 August 2023 — same parameters as the departures above.

pared-down screenshot of BirdCast Species On The Move, noticeable Beginning Arrivals, Upper Midwest & Northeast

The tables change every day, dropping past dates and picking up new species in the future, so check out BirdCast’s Species on the Move to find out what’s happening near you.

p.s. How will you know if it’s worth going birding? Check BirdCast Migration Tools for forecast maps, live maps and alerts.

(photos from Wikimedia Commons, Charity Kheshgi, Chuck Tague, Kuldeep Singh. Tables are modified screenshots from BirdCast’s Species On The Move for the Upper Midwest and Northeast. Be sure to check BirdCast for the latest data)

Hummingbird Day on August 19

Books & Events, Migration, Songbirds
Ruby-throated hummingbird, July 2014 (photo by Steve Gosser)

9 August 2023

Have you noticed a lot of ruby-throated hummingbirds at your feeders lately? Their fall migration is already underway so this month is the perfect time to see them up close at Powdermill.

Powdermill Nature Reserve, operated by the Carnegie Museum of Natural History, has one of the longest continually-running bird banding stations in the U.S. Throughout the year they see species abundance ebb and flow based on weather and migration timing.

Ruby-throated hummingbirds (Archilochus colubris) start their fall migration earlier than many other species so they’re more abundant than usual now. Come to Westmoreland County for a family friendly hummingbird event on:

Hummingbird Day, Saturday 19 August 2023, 9:00am-noon at
Powdermill Nature Reserve
1795 Route 381
Rector, PA 15677

Powdermill Nature Center (photo embedded from CMNH Powdermill website)

Learn about hummingbirds, the plants that attract them, and how to care for your feeders so the birds stay healthy. There will also tips on taking great bird photos. And if the weather is good and the birds cooperate we(*) will get to see hummingbirds up close like this one in the bander’s hand. This bird was banded by Bob Mulvihill in Marcy Cunkelman’s garden in July 2015.

(*) I say “we” because I’ll be there, too, to teach you about hummingbirds. I’m looking forward to it!

Ruby-throated hummingbird in bander’s hand, July 2015 (photo by Kate St.John)

This event is free but do register here in advance so Powdermill knows to expect you. As the registration page says:

Events fill up fast! Registration is recommended to guarantee your spot and help us plan timing, seating, and/or trail routes. If there are spots available at the time of the program, non-registered individuals can join on a first-come, first-served basis.

— CMNH: Hummingbird Day Event

Click here for more information. Hope to see you there.

(hummingbird photos by Steve Gosser and Kate St. John, Powdermill photo embedded from carnegie.org)

Bird News Lately

Migration, Musings & News
Celebrity in Central Park, Flaco the Eurasian eagle-owl, February 2023 (photo from Wikimedia Commons)

28 July 2023

A selection of photos and videos this month around the web:

In February a Eurasian eagle-owl named Flaco escaped from the Central Park Zoo and became a celebrity. He’s still hanging out in July.

In Florida, swallow-tailed kites are preparing to migrate.

In Europe, migration has already begun across the Strait of Gibraltar.

(embedded from Twitter)

One Place, One Time, A Quarter Million Warblers

Bird Behavior, Migration
Bay-breasted warbler (photo by Chuck Tague)

27 May 2023

Imagine spending a day standing on dunes in cold wet weather and seeing a river of a quarter million warblers fly by. This amazing phenomenon was the perfect storm of location, migration and bad weather.

In late May boreal forest warblers such as Cape May, bay-breasted and Tennessee have reached or surpassed Tadoussac, Quebec on the way to their breeding grounds further north. They aren’t nesting yet, so if the weather turns sour they head back south temporarily to wait it out.

Google map showing location of Tadoussac bird count on 24 May 2023 (screenshot from Google maps)

The weather forecast for 24 May looked promising for this perfect storm as Ian Davies (@thebirdsguy) writes in the day’s eBird checklist:
“There were southwest winds overnight (tailwinds good for migration), combined with a big cold front arriving right around dawn, bringing rain, strong northwest winds, and colder temperatures — the same setup that has resulted in flights of tens or hundreds of thousands of birds in past Mays.”

Hoping for a river of warblers, Ian and 11 others headed out to the Tadoussac dunes to count birds. In 11.25 hours they saw 263,771 birds in 96 species! Ian writes:

The first couple hours of daylight featured drizzle and strong winds, and not many birds until about 6:45 … then 500 birds/minute by 7:30. The Tadoussac river of warblers had begun.
This flight continued at 300-500 birds/minute until about 9:20, at which point the rain dropped significantly, and the flood gates opened, as many as 1345 warblers/minute raging past in a torrent of flight calls and glowing songbirds. Birds were everywhere, below eye level, flying between people, pouring through the bushes, landing on the sand, and one Cape May Warbler even tried to land on my arm. A Red-eyed Vireo flew into someone. It was madness. …
For one period of time, the rate of warblers was 80,000/hour.

— ebird checklist for 24 May 2023 Tadoussac

Here’s just one of the many videos attached to the checklist. See the checklist for amazing photos, videos and counts.

The location was key to this phenomenon. Tadoussac is located on the northwest coast of the wide St. Lawrence River which funnels birds heading south. If you look at the videos you’ll see that the cameras are pointed toward the St.Lawrence River — east/southeast — and that all the birds are flying southwest.

Satellite Google map showing location of Tadoussac bird count on 24 May 2023 (screenshot from Google maps)

These birds had made it further north but when bad weather arrived they changed direction to escape the storm. Flying on the northwest wind they reached the unsheltered coastal dunes at Tadoussac so they headed southwest to the forest.

What a privilege it must have been to witness a quarter million warblers in just one day.

(maps are screenshots from Google maps; tweet embedded from Ian Davies @thebirdsguy)