Category Archives: Migration

Deadly Attraction

Downtown Pittsburgh glows at night (at left) while the Pitt Victory beams rise from behind the dark spruce tree, 17 Sept 2018 (photo by Kate St. John in Greenfield)

For migrating songbirds there are two deadly attractions in this photo.

On the left, Downtown Pittsburgh glows in the distance illuminating the night sky.  At center-right, Pitt’s blue Victory Lights beam up from the Cathedral of Learning roof. (The building itself is hidden by the dark spruce.)

Downtown Pittsburgh glows every night.  Pitt’s Victory Lights glow on Saturday and Sunday nights after Pitt wins a football game.  Photographer Dave DiCello tweeted his photo, below, of the Victory Lights on 15 September after Pitt beat Georgia Tech.

City lights are a fatal attraction for songbirds because they migrate at night using celestial lights for navigation. Lured by artificial lights they become confused and circle them. Some crash into buildings. Others land in the city and try to leave after dawn but mistake glass reflections of trees and sky for the real thing. They fly headfirst into glass buildings and windows. Some are stunned, many die. Warblers and wood thrushes are especially vulnerable. Every year nearly half a billion birds die this way in the U.S.

You can help birds survive Pittsburgh’s bright lights, both now and in the future.  Jon Rice at BirdSafe Pittsburgh is mobilizing volunteers to help stunned birds now and to collect data on deaths to mitigate the future.

Here’s what you can do:

  • Report Dead Birds:  If you find a dead bird pause to report it. Enter what, where and when in BirdSafe’s I Found A Bird online tool.  Your smartphone automatically knows “where.”
  • Volunteer with BirdSafe: Walk a route for BirdSafe to rescue stunned birds and collect the dead ones(*). See the BirdSafe Volunteer page for more information.  Contact BirdSafe here.

A 10 September 2018 op-ed in the New York Times by Andrew Farnsworth and Kyle G. Horton explains how the 9/11 Tribute of Light made an easy change that solved this problem.

WTC Tribute of Light, New York City, 11 September 2010 (photo from Wikimedia Commons)

After the Tribute began in 2003, people noticed that thousands of birds were lured to the lights and dying there, so in 2005 New York City Audubon mobilized volunteers to monitor the beams. When volunteers count 1,000 birds circling in the beams or if a bird is found dead, the lights are turned off for 20 minutes.  That’s all it takes for the “stuck” birds to resume their migration and not become trapped again.  Since 2005 only two birds have died during the Tribute of Light!

The article also describes how we can apply this knowledge across the U.S., including in Pittsburgh.

We also discovered that on average, half of the total passage of autumn bird migration density over the continental United States occurs on fewer than 10 nights. With migration forecasts developed by scientists at the Cornell Lab, the University of Massachusetts at Amherst and Oxford University, these cities and others could determine the optimal nights to dim or extinguish lights so that birds can pass safely.

(from Farnsworth and Horton New York Times 9/10/2018 op-ed)

This easy solution will save migrating birds but we need the data to convince others to make it happen. Please help the birds by helping BirdSafe Pittsburgh.

(photo credits: Downtown Pittsburgh and Pitt Victory Lights by Kate St. John. Cathedral of Learning and Pitt Victory Lights embedded tweet by Dave DiCello. 9/11 Tribute of Light from Wikimedia Commons; click on the caption to see the original)

(*) The dead birds are valuable for science. They become part of the Carnegie Museum of Natural History’s collection.

Long Distance Snails

California horn snail (photo by tiyumq via iNaturalist)

The ancestors of this saltwater snail changed oceans twice.

California horn snails (Cerithideopsis californica) are native to the Pacific Ocean from the California coast to Baja California Sur in Mexico, but a DNA study published in 2011 found they contain traces of a closely related Atlantic snail, Cerithideopsis pliculosa, and vice versa.  The DNA mixing went like this:

  • 3 million years ago North and South America joined at Panama, blocking sea travel between the two oceans.
  • 750,000 years ago, Pacific Ocean snails somehow traveled east to invade the Atlantic.
  • 72,000 years ago, Atlantic Ocean snails came back to invade the Pacific.

How did the snails cross Central America from one ocean to another?  Twice?

On Throw Back Thursday, find out in this vintage article: Flying Snails

Spinning Like A Top

Red-necked phalarope, September 2011 (photo by Andy Reago & Chrissy McClarren via Wikimedia Commons)

You would think that all shorebirds live at the shore but not this one.  The red-necked phalarope (Phalaropus lobatus) spends most of his life at sea, spinning like a top.

Phalaropes live inland from June through August while they’re breeding in the sub-arctic northern hemisphere but most of the year — November through March — they’re out to sea on the tropical ocean.  Their food is on or near the water’s surface.

Phalaropes feed by swimming in tight circles, rapidly picking tiny insect larvae, crustaceans, and mollusks from the water.  Their feet are specially equipped for swimming. They have lobed toes like coots.  (“Phalarope” is Ancient Greek for “coot toes.”)

In winter red-necked phalaropes don’t have red necks. Right now they’re wearing gray “basic” plumage, shown above, as they migrate to their final destinations in the southern hemisphere. Western birds take an inland route through the western U.S. but you probably won’t see one in the east. Except for a few stopovers at the Great Lakes, the eastern population flies immediately to the Atlantic Ocean. 

If you really want to see red-necked phalaropes in beautiful breeding plumage you’ll have to wait for spring.  Sparky Stensaas filmed this group feeding at their breeding grounds in Churchill, Manitoba, Canada.

Red-necked Phalarope spin feeding Churchill, Manitoba, Canada from Sparky Stensaas on Vimeo.

Look how fast they spin!

(photo from Wikimedia Commons; click on the caption to see the original. video by Sparky Stensaas on Vimeo)

Broad-winged Hawks On The Move

Broad-winged hawk (photo from Wikimedia Commons)

Mid-September is the peak of broad-winged hawk migration in Pennsylvania as these woodland raptors head for the forests of Central and South America.

Broad-winged hawks (Buteo platypterus) breed in North American forests but spend only four months of the year up here.  In late August they start to move south, reaching the forests in Central and South America by early November. 

What’s unusual about broad-wings is that they travel in flocks — most raptors don’t — and they watch each other for flight cues.  If one finds a thermal with good lift, others join him and rise on it as well.  Soon they form a “kettle” of hawks stirring round and round in the rising air.  As each one reaches sufficient altitude it sets its wings and glides south to find the next thermal.

If the weather’s good this weekend, hundreds if not thousands of broad-wings will kettle up and stream out over hawk watches in the Mid-Atlantic.  Here’s what it looks like on a good day, recorded at Ashland Hawk Watch in Hockessin, Delaware on September 15, 2013.

Make plans to visit a hawk watch soon. Here’s how to find one near you: Hawk Watch Information

Living In The Wind

Hudsonian godwits (Limosa haemastica) breed on remote tundra and sedge meadows in Canada and Alaska, then spend the winter as far south as the tip of South America.

To make this long journey they assemble in flocks in August on wet prairies and mudflats where they use their long upturned bills to probe for invertebrates and plant tubers.

Since their food is found in wide open places, Hudsonian godwits spend their lives in the wind.  I hadn’t thought about this until I searched for videos and hear the wind on every soundtrack.

At top, Hudsonian godwits fly in slow motion in the moaning wind.  Below a flock of 2,500 assembles at James Bay, Canada in lots of wind.

Occasionally a lone Hudsonian godwit is found during migration, like this one at Bowdoin National Wildlife Refuge in Montana.  Even here it’s windy.

(videos from YouTube; click the YouTube logo to see the originals)

Egrets Fly North Before South

  • Great egret in Montour County, August 2018 (photo by Lauri Shaffer)

Great egrets (Ardea alba) are southern and coastal birds with only a few breeding sites north of Mason-Dixon. However, those few sites don’t account for the high number of egrets we see outside their breeding range in August.

As it turns out, great egrets disperse widely after they’re done breeding.  Many move north before flying south for the winter.

Lauri Shaffer posted these photos on Facebook with the comment:  “Love August when the Great Egrets finally make it north to Montour County!” (Pennsylvania)

I wish great egrets would stop in Pittsburgh.

photos by Lauri Shaffer at

Non-Stop 2,500 Miles

Whimbrel at Galapagos, Ecuador (photo from Wikimedia Commons)
Whimbrel at Galapagos, Ecuador (photo from Wikimedia Commons)

Every fall this bird performs an amazing feat of physical endurance.  It flies non-stop over the ocean for 2,500 miles.

The whimbrel (Numenius phaeopus) is a long distance migrant that occurs on every continent except Antarctica because it breeds in the far north and winters in the southern hemisphere.

Whimbrel range map (BirdLife International via Wikimedia Commons)

Most North American whimbrels spend the winter in coastal South America.  To get there, some travel the western route down the Pacific Ocean to Columbia, Ecuador, Peru and Chile.

Others take an eastern route, flying across northern Canada in mid-July to spend two weeks fattening up on the shores of the U.S. and Canada. Then they launch over the Atlantic and fly non-stop to Venezuela, the Guianas and Brazil.  What’s the air distance from Cape Cod to Venezuela?  2,500 miles.

We didn’t know the whimbrels’ route until the Center for Conservation Biology began satellite tagging them in 2008.  In August 2012 they made an astonishing discovery.  Three of their 20 satellite tagged whimbrels made a wide arc over the Atlantic, far out to sea, before heading for the coast of Brazil.  One of them (red line) traveled 4,355 miles non-stop before touching down. At 30 miles per hour, the trip took six days. Read more at the Center for Conservation Biology website.

Whimbrels' transoceanic flights from Mackenzie Delta to South America (map from Center for Conservation Biology, August 2012)
Whimbrels’ transoceanic flights from Mackenzie Delta to South America (map from Center for Conservation Biology, August 2012)

By now whimbrels have been on the move for several weeks.  When you see one you’ll know why he’s eating so much.  He has a big trip ahead of him.

(photo and map of the whimbrel’s range from Wikimedia Commons. Migration routes map from Center for Conservation Biology.  Click on the captions to see the originals.)

Sugar Doesn’t Hurt Me

Hummingbird at the feeder (photo by Marcy Cunkelman)
Ruby-throated hummingbird at the feeder (photo by Marcy Cunkelman)

By August in Pennsylvania, ruby-throated hummingbirds (Archilochus colubris) have finished breeding and all of them, young and old, are fattening up for their migration to Central America.  Many are visiting backyard feeders.

Last week on PABIRDS Rob Blye posted a collection of interesting questions about feeding hummingbirds, including someone’s concern about sugar. Here’s a summary of the feeder discussion with embedded links to the original text.

Do young hummingbirds imprint on feeders as a preferential food source and ignore natural food sources?

No.  Scott Weidensaul writes that as much as 40 percent of the hummingbirds’ diet is made up of insects and other small arthropods which they pursue while away from our feeders. There’s no need to worry that they’re getting an unbalanced diet.

Is sugar bad for hummingbirds?

Not at all. Sugar is bad for humans but fine for hummers. Scott Weidensaul writes: “Flower nectar and a white cane sugar/water mix are essentially identical sucrose fluids.  Four parts water and one part white sugar neatly replicates what they’re getting from flowers. “

Can we offer a different sweetener than sugar? What about honey?

Absolutely not!  Scott writes that “substitutions are dangerous. Organic/brown/turbinado sugar or molasses can pack fatally high levels of iron, to which hummers are exquisitely sensitive, while honey, once diluted, becomes a stew of dangerous bacteria and fungi.”

Is it OK to hang hummingbird feeders if you cannot clean them frequently?

No.  Spoiled food is dangerous for hummingbirds and it spoils daily in 90 degree weather. Clean your feeders thoroughly and regularly. Empty, clean and refill daily when it’s 90 degrees. You can extend this to every few days when the high is 60.  Click here for guidelines from Aududon.

Should we add something to the sugar-water to prevent spoilage?

No.  Scott writes, “avoid new products that claim to deter spoilage. Hummingbird experts are deeply suspicious about the safety of such additives.”

How do you attract hummingbirds if you can’t clean your feeders that often?

Ellen from Cumberland County had that problem so she planted salvia and other hummingbird favorites. The hummingbirds now “come back every year looking for their flowers and guard them zealously.”  Read her flower list on PABIRDS and/or this list of top 10 flowers for hummingbirds at The Spruce.

The bottom line is this:  Sugar doesn’t hurt hummingbirds, but spoiled food does.  Clean your feeders thoroughly and often, especially in August’s heat!

(photo by Marcy Cunkelman)

Fall Migration Has Begun

Bonaparte's gull and American avocets at Conneaut Harbor, late July 2013 (photo by Steve Gosser)
Bonaparte’s gull and American avocets at Conneaut Harbor, late July 2013 (photo by Steve Gosser)

Late July doesn’t look or feel like autumn but fall migration has already begun.

Shorebirds are some of the earliest species to start their journey south.  Last weekend brought a good assortment to Gull Point at Presque Isle State Park in Erie, PA.   Here are a few of the migrants we would have seen if we’d been there.

American Avocets (Recurvirostra americana), above, raise only one brood per year and will leave the breeding grounds immediately if their nest fails.   Avocets are always a treat in Pennsylvania because they breed far west of here and could easily bypass us if they wanted to.  Instead, some fly to the east coast before moving south.  Steve Gosser found a pair hanging out at Conneaut, Ohio in July 2013.  (The bird with the black head is a Bonaparte’s gull. He’s also migrating.)

Sanderlings (Calidris alba), below, nest on the tundra in high arctic Canada, mostly north of the Arctic Circle.  These small birds have one shot at breeding so if it doesn’t work they form flocks with other failed breeders in late June and move south in July.

Sanderling on sand, July 2013 (photo by Steve Gosser)
Sanderling on the sand, July 2013 (photo by Steve Gosser)


Short-billed dowitchers (Limnodromus griseus) breed from Hudson Bay to western Labrador and in northern Manitoba and Alberta.  Failed breeders leave the breeding grounds in late June while successful females depart in early July followed by males later in the month.  Juveniles leave in August. Once they start passing through we’ll see short-billed dowitchers in Pennsylvania for several weeks.

Short-billed dowitchers, July 2013 (photo by Steve Gosser)
Short-billed dowitchers, July 2013 (photo by Steve Gosser)


The lesser yellowlegs’ (Tringa flavipes) lifestyle dictates when each family member leaves the breeding grounds (Alaska to Hudson Bay) for their winter home (primarily in Suriname).  Successful females head south in June as soon as their eggs hatch and the young walk off the nest.  The males protect their chicks until they fly then head south, too.  The juveniles form flocks and fend for themselves until they decide to leave.

Lesser yellowlegs, July 2013 (photo by Steve Gosser)
Lesser yellowlegs, July 2013 (photo by Steve Gosser)


Visit Lake Erie’s shore for a good look at shorebirds.  The best places close to Pittsburgh are the harbor area at Conneaut, Ohio or Gull Point at Presque Isle State Park in Erie, PA.


(photos by Steve Gosser)

p.s. Here’s the complete shorebird list from Gull Point on July 21-22, 2018, gathered from eBird:

  • American Avocet
  • Semipalmated Plover
  • Piping Plover (local breeder, two nests)
  • Killdeer
  • Whimbrel
  • Ruddy Turnstone
  • Redknot
  • Stilt Sandpiper
  • Sanderling
  • Dunlin
  • Least Sandpiper
  • Pectoral Sandpiper
  • Semipalmated Sandpiper
  • Short-billed Dowitcher
  • Spotted Sandpiper
  • Greater Yellowlegs
  • Lesser Yellowlegs