Terrestrial birds that migrate over the ocean will land on ships to rest and refuel, especially during bad weather. Some birds are exhausted by the time they land. The ships attract insects that are eaten by songbirds. The songbirds attract birds of prey and shrikes.
The video showcases 70 species seen during Europe voyages. Each half of the video is in taxonomic order. My favorites were the birds of prey and a colorful bird that was new to me — the black-headed bunting. Don’t miss the hobby, the peregrine and the long-eared owl.
The path of the Harrisburg female peregrine (Red, 46/BS, ID#24660) looks quite promising. She flew first to Nockamixon (19 Sept), then west and south to Lamb’s Knoll (2 Oct) and Newtowne Neck near Compton, Maryland (4 Oct). The enhanced map below includes her banding location in Harrisburg. Click here for her path on the Motus website which does not include her banding location.
Harrisburg male, White, 22/BZ (ID# 24662)
Initial data on the Harrisburg male (White, 22/BZ, ID#24662) were clouded by inaccuracies that placed him in both Reading, PA (Drasher) and Saskatchewan, Canada — 1,600 miles away — on the same day.
After removing the Saskachewan error there was still one more puzzle. The data table indicates that Harrisburg White flew 766 miles four times — from western Ontario (Harrington) to the Bay of Fundy (Gardner Creek) and back again. Would a bird have done this? And could he have made one of those trips in a single day, 24-25 August, in a head wind? Hmmm! Doubtful.
With those questions in mind I created the enhanced map below, adding his banding location and removing Gardner Creek (which may still be on his MOTUS map here). While his data is under review Harrisburg White is still on the move. He showed up near Aurora, Ontario on 16 November.
Nazareth, female, Red, 20/CA (ID# 24665)
Hatched on a clinker silo at Lehigh Cement in Nazareth, Pennsylvania this female (Red, 20/CA, ID#24665) logged three data points on Amherst Island in Lake Ontario: 51 seconds on 17 and 19 July and three hours on 6 August. Without other locational data MOTUS cannot generate a map so I created one below with two points while her data is under review. Click here for her data table on the MOTUS website.
Data uncertain: Pittsburgh, female, Blue, 19/CA (ID# 24664)
Steppe eagles (Aquila nipalensis), pictured above, breed on the steppes of Eurasia and spend the winter in Africa, the Middle East, Pakistan, India or Southeast Asia, passing through Central Asia on their way south.
Steppe eagles are endangered in Russia and Central Asia, threatened by persecution and power lines which they encounter on migration so the Russian Raptor Research and Conservation Network has fitted 13 of them with cell-enabled backpacks to track their paths. They plan to mitigate the most dangerous locations frequented by eagles.
The tracking backpacks send four text messages a day with date, time and the eagles’ GPS coordinates. If the bird is far from the cell network, the tracker stores the data until the eagle gets near a tower.
This method worked well in 2018 because most of the eagles traveled near the Russian cell network. This year, however, an eagle named Min spent the summer far from the network in a remote part of Kazakhstan. Her backpack stored months of data that it couldn’t transmit until she flew near a cell tower in Iran (map below).
In October the researchers were stunned to receive a cellphone invoice with eagle-sized roaming charges. They’d budgeted 15 roubles/message but roaming in Iran is 49 roubles/message. In just one texting session Min used up the entire year’s budget for all the eagles!
What to do? They set up a crowd-funding appeal that raised more than enough to cover this year’s charges (100,000 roubles) and Russia’s Megafon network offered to cover the cost, too. So the project is saved.
NOTES: Steppes are prairies or scrubland similar to the Great Plains and Great Basin of North America. Steppe eagles face an additional threat: Because they eat carrion they are dying of diclofenac, just as vultures are.
Though it’s nearly mid October I saw monarch butterflies migrating through Pittsburgh on Thursday and Friday October 10 & 11. Their timing seems late, but they were given a boost by August-like weather early this month.
Now that the weather has changed unwelcome insects will invade our homes including Asian ladybeetles (Harmonia axyridis) that resemble native ladybugs but don’t act like them. Also called “harlequin ladybirds,” they overwinter indoors, make a stink, and bite when frightened.
A hundred years ago we thought this bug was a great idea and repeatedly introduced it to the U.S. to control aphids. The introduced ladybeetles never made it in the wild until a population was found thriving near New Orleans in 1988. After that they spread like wildfire across the eastern U.S. and into Canada.
Thirteen years later they became established in South America and Europe(*). By 2004 they were in southern Africa. They hadn’t been introduced. How did they get there?
A 2010 study of their genetic markers revealed that those three continents were invaded by the eastern North America population. In a move called the bridgehead effect, Asian ladybeetles in the U.S. used our continent as a jumping off point to colonize Europe, South America and Africa.
In the American West there’s a 3-inch long katydid called a Mormon cricket (Anabrus simplex) that cannot fly but it sure can walk.
We hardly notice Mormon crickets until millions swarm and march across the landscape, advancing more than a mile a day like a Biblical plague of locusts. Naturally scientists wondered what makes them do it.
A 2006 study discovered that the swarms are driven by hunger and fear. The crickets are hungry for protein and salt so they start to migrate, but the bugs are cannibals and will eat each other if they can. Those at the back of the pack pursue the front line to catch and eat them. Fear forces the crickets to keep track of their neighbors and constantly on the move.
Despite the danger from behind, individuals sometimes double back into the crowd. If enough of them do it the whole swarm changes direction. How does this happen? What signals such a change?
We concluded that the mechanism through which locusts agree on a direction to move together (sometimes with devastating consequences, such as locust plagues) is the same we sometimes use to decide where to live or where to go out: we let ourselves be convinced by those in our social network, often by those going in the opposite direction.
We don’t necessarily pay more attention to those doing the same as us, but many times [we pay more attention] to those doing something different.
Songbird migration is underway across the continent but we can’t see it happening outdoors because the birds travel at night. However, we can watch them online.
Radar can see birds in flight so Cornell Lab of Ornithology’s BirdCast uses national radar data to plot where, when and what direction the birds are moving. Click the BirdCast link to see the most recent video. Watch sunset (red bar) sweep across the continent and the birds start to move, then sunrise (yellow bar) sweep across and migration stops for the day. The date above the map is a pulldown menu for selecting prior nights.
The BirdCast screenshot above was taken on Tuesday 3 September on a night when many birds left Pittsburgh on their way to the Gulf coast. At 4:50am you can see them lighting up the BirdCast map from southwestern Pennsylvania to Mississippi.
Before BirdCast existed, I watched weather radar for a snapshot of current bird activity. BirdCast filters the weather map so you see only the birds. The Weather Service does not so you’ll want to check out this vintage article — Watch Migration On Radar — for a quick tutorial on how to read the map.
The screenshot below was taken from Great Lakes weather radar on the same date and time as the BirdCast snapshot at top. Notice the differences!
Wisconsin and Lake Michigan are brightly colored on the weather map because of heavy rain. That same area is a dark spot on BirdCast because birds don’t migrate in a storm. BirdCast also shows no birds moving in Florida; Hurricane Dorian was there.
Last night, Sep 4-5, the wind was from the north and skies were clear west of the Appalachians. BirdCast and weather radar both show birds on the move from Pennsylvania and Illinois to the Tennessee and Mississippi Valleys.