Archive for the 'Migration' Category

Mar 25 2017

Birds Were On The Move Overnight

Published by under Migration

National Weather Service radar, 25 Mar 2017, 4:48am (screenshot from NOAA)

National Weather Service radar mosaic, 25 Mar 2017, 4:48am (screenshot from NOAA)

What are the blue dots in the eastern U.S. on last night’s radar?  Birds!

South winds overnight prompted songbirds to move north from Florida to the Great Lakes.  A storm front approaching the Mississippi River and rain from Chicago to Massachusetts brought them to a halt.

Today should a good day to go birding in the areas that have those fuzzy blue dots.  Get out there before it rains.

 

(screenshot from the National Weather Service full-res radar mosaic)

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Mar 20 2017

Birds On The Move Every Day

Published by under Migration

Birds in the Americas are on the move every day of the year — even in winter.

 Animation by Frank La Sorte/Cornell Lab of Ornithology

Migration animation by Frank La Sorte/Cornell Lab of Ornithology

 

This animation by Frank La Sorte at Cornell Lab uses eBird data to show the movements of 118 species in the western hemisphere. Yes, your eBird checklists can lead to something useful and beautiful like this.

Click on the link to learn which species are on the map and how it was made in this January 2016 news from Cornell Lab:  Mesmerizing Migration: Watch 118 Bird Species Migrate Across a Map of the Western Hemisphere.

 

(animation by Frank La Sorte/Cornell Lab of Ornithology. Click on the image to see the original)

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Mar 13 2017

Of Llamas and Possums

Published by under Mammals,Migration

Llama on Machu Picchu, Opossum in western Canada (photos from Wikimedia Commons)

Llama on Machu Picchu, Virginia opossum in western Canada (photos from Wikimedia Commons)

What do llamas and opossums have in common?

Their ancestors swapped continents during the Great American Interchange.  They now live a world away from their country of origin.

The “Great American Interchange” sounds like a flea market or a swap meet but it’s actually the movement of species between North and South America when the two continents joined at Panama three million years ago.

Before the interchange our continent had members of the camel family; South America did not.  The camelids walked south and thrived on their new continent in the wild as guanacos and vicuñas and domesticated as llamas and alpacas.  In the meantime camels went extinct here in North America.  So there are wild camels in Peru but we have none.

Other animals made the journey, too. Here are just a few of the northern species that became successful in South America: camelids, squirrels, cottontail rabbits, deer, wild horses, peccaries, otters, raccoons, wolves, cougars, American sparrows (Emberizidae), trogons and condors.  Click here for the complete list.

Initially the interchange was symmetrical with the same number of species going north and south but the result was lopsided.  More northern species survived their move to South America than did southern species transplanted to the north.  This was due in part to the difficult trek northward (deserts en route), our less hospitable climate (winter!) and the long isolation of South American fauna.

Opossums were one of the few success stories.  We had no marsupials in North America until the Virginia opossum’s ancestors made the journey and thrived on our continent.  Many of their relatives still live in South America.

So what did we get when South American animals walked north?  Not as much as you’d think: opossums, armadillos, porcupines, cougars, parrots, hummingbirds, tanagers, and tyrant flycatchers.  Click here for the complete northbound list.

Cougars (Puma concolor) are on both lists because they were originally from North America and walked into South America. After they went extinct in North America the southern ones walked north to repopulate our continent.

We humans were part of the Great American Interchange, too.  Our species’ movement around the globe was made possible by continental land bridges.

 

(photos from Wikimedia Commons: llama at Machu Picchu, Virginia opossum in western Canada. Click on each link to see the original.)

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Feb 23 2017

Two Weeks Early!

Published by under Migration,Songbirds

Common grackle (photo by Steve Gosser)

Common grackle (photo by Steve Gosser)

On Throw Back Thursday:

Last year that I reported that common grackles usually return to my city neighborhood on March 5.

Well, this year they’re ahead of schedule.  They arrived here in Pittsburgh on Tuesday February 21 and even earlier at Moraine State Park, 45 miles further north, on Sunday, February 19.

The grackles are two weeks early!

I noticed them when I heard them “skrink.”

Click on last year’s article below to watch the grackles puff and squeak on video.

Grackle Day

 

p.s. Have you seen other “early birds” this week?

(photo by Steve Gosser)

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Feb 15 2017

Red-tailed Hawks Adjust Their Plans

Red-tailed hawk (photo by Cris Hamilton)

Red-tailed hawk, 2012 (photo by Cris Hamilton)

If you don’t look at all the data you’ll probably be fooled.

For the past 30 years the number of red-tailed hawks migrating past hawk watches has declined across North America except at certain western sites.  With only this information to go on, you’d think that the species is in trouble.

But Neil Paprocki of HawkWatch International and his colleagues looked further. They compared hawk watch counts to the data gathered during Christmas Bird Counts in December-January and found that since 1984 red-tailed hawks have stayed in northern latitudes in much greater numbers.  They noted that red-tail counts declined at 43% of the hawk watches and increased on 67% of the Christmas Bird Counts.

As the climate warms and the winters are milder there’s less snow cover in the northern latitudes so it’s easier for the hawks to find food.  Fewer of them are bothering to travel south.

Red-tailed hawks are adjusting their plans.

 

Read more about the study here in The Condor: Combining migration and wintering counts to enhance understanding of population change in a generalist raptor species, the North American Red-tailed Hawk.  Laurie Goodrich of Hawk Mountain Sanctuary was a member of the study team.

(photo by Cris Hamilton)

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Jan 21 2017

Seasonal Movements: One Owl

Eastern screech-owl, Schenley Park (photo by Kate St. John)

Eastern screech-owl, Schenley Park (photo by Kate St. John)

Last month I mentioned that a pileated woodpecker lives in Schenley Park, but only in the winter.  Here’s another bird that seems to do the same thing.

On sunny days this eastern screech-owl perches motionless in an unusual tree opening.  He’s not there every day in winter, but he’s never there when spring comes.

Though the range maps says eastern screech-owls live in Pittsburgh year round, this individual bird probably lives in Schenley during the winter and goes somewhere else to nest.

Range map of eastern screech-owl (linked from All About Birds website)

Range map of eastern screech-owl (linked from All About Birds website)

 

Sorry … I’m not going to tell you exactly where he is because too much public attention will scare him off.  And if you find him, please don’t publicize his location for the same reason.

 

(photo by Kate St. John)

p.s.  In January this blog has 400-700 readers a day.  That’s a lot of public attention.

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Dec 31 2016

Seasonal Movements: One Woodpecker

Male Pileated Woodpecker (photo by Dick Martin)

Range maps can obscure the seasonal movement of birds.

For instance, the range map for pileated woodpeckers, below, shows them in western Pennsylvania all year long but they’re not everywhere. There are none in Schenley Park in the spring and summer.

Pileated woodpecker range map. Green means year-round. (from Wikimedia Commons)

Pileated woodpecker range map. Green means year-round. (from Wikimedia Commons)

However, a male pileated woodpecker comes to Panther Hollow for the winter.  He announces his presence when he sees me on the trail.

It’s a treat to see him as I walk through Schenley Park.

 

(photo by Dick Martin, range map from Wikimedia Commons; click on the map to see the original image)

 

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Nov 17 2016

Fox Sparrows Are Passing Through

Published by under Migration,Phenology

Fox sparrow (photo by Steve Gosser)

Fox sparrow (photo by Steve Gosser)

I saw my first fox sparrow this fall at Hillman State Park on Sunday, November 13.

Fox sparrows (Passerella iliaca) breed in Canada, Alaska and the northern Rockies and spend the winter in the southern U.S. so we typically only see them on migration in Pittsburgh.

These birds are never numerous and are often hard to find.  Sometimes you hear one scratching in dead leaves in the underbrush but he’s well camouflaged.  Fortunately the bird at Hillman flew into a tree with a flock of dark-eyed juncos so I could see him.  A nice surprise.

Look for surprises among the sparrows this week.  Perhaps the ducks and geese will arrive at last.

This phenology for early November still applies because our weather’s been so warm:

What to Look For: Early November

 

(photo by Steve Gosser)

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Nov 03 2016

Golden Day

Golden eagle flies past the Allegheny Front Hawk Watch, 1 Nov 2016 (photo by Anthony Bruno)

Golden eagle flies past the Allegheny Front Hawk Watch, 1 Nov 2016 (photo by Anthony Bruno)

If you want to see golden eagles, now’s the time to visit the Allegheny Front Hawk Watch in Cairnbrook, PA.  Five of us made the trip last Tuesday, November 1, and we weren’t disappointed.  It was a 20-golden day.

Golden eagles (Aquila chrysaetos) migrate through Pennsylvania from late October through the end of November leaving their breeding grounds in northern Canada for wintering sites in the Appalachians from West Virginia to North Carolina.

Goldens fly almost daily during that period but you won’t see them at the Allegheny Front unless the wind has an eastward component that pushes them toward the Watch site.  Tuesday’s forecast called for a south-southeast wind.  Excellent!

Thanks to Donna Foyle and Anthony (Tony) Bruno I can show you what we saw.

Upon arrival the golden eagle statue greeted us at the parking lot.

Statue of the Golden Eagle at Allegheny Front Hawk Watch (photo by Donna Foyle)

Statue of the Golden Eagle at the Allegheny Front Hawk Watch (photo by Donna Foyle)

Walking from the parking area to the mountain edge we could see it was hazy. Though everyone wasn’t present at the same time, the Hawk Watch had 11 observers and 55 visitors that day.

Approaching the Allegheny Front Hawk Watch (photo by Donna Foyle)

Approaching the Allegheny Front Hawk Watch (photo by Donna Foyle)

We all faced north, watching for raptors.  Many red-tailed and sharp shinned hawks flew by since this is the height of their migration, too.

Watching for the next golden eagle, Allegheny Front Hawk Watch, 1 Nov 2016 (photo by Donna Foyle)

Watching for the next golden eagle at the Allegheny Front Hawk Watch, 1 Nov 2016 (photo by Donna Foyle)

Sharp shins, small as they are, love to attack red-tailed hawks when they get the chance.  Donna Foyle captured the action as this “sharpie” forced a juvenile red-tail to dive out of his way.

Sharp-shinned hawk attacks a red-tailed hawk on migration, 1 Nov 2016 (photo by Donna Foyle)

Sharp-shinned hawk attacks a red-tailed hawk on migration, 1 Nov 2016 (photo by Donna Foyle)

 

And there were golden eagles.

This gorgeous bird flew past low enough for us to see his golden head and nape.  (Great shot, Tony!)

Golden eagle, 1 Nov 2016 (photo by Anthony Bruno)

Golden eagle, 1 Nov 2016 (photo by Anthony Bruno)

The white crescent under the wing is a sign that this golden eagle is immature.

Golden eagle, 1 Nov 2016 (photo by Anthony Bruno)

Golden eagle, 1 Nov 2016 (photo by Anthony Bruno)

 

And yes, it’s odd for so many humans to sit on the edge of a mountain. This eagle checked us out as he flew by.  “What are all those humans doing?”

Golden eagle looks at the all the people at the Hawk Watch, 1 Nov 2016 (photo by Anthony Bruno)

Golden eagle looks at the all the people at the Hawk Watch, 1 Nov 2016 (photo by Anthony Bruno)

 

We had a great day at the Allegheny Front … and we happened to leave before the last 10 eagles flew by.  (Golden eagles are famous for migrating in the last hour before sunset.)

Karyn, Donna, me, Geralyn and Kathy, Allegheny Front Hawk Watch (photo courtesy Donna Foyle)

Happy Hawk Watchers: Karyn Delaney, Donna Foyle, Kate St. John, Geralyn Pundzak, Kathy Miller, Allegheny Front Hawk Watch, 1 Nov 2016 (photo courtesy Donna Foyle)

Visit the Allegheny Front Hawk Watch soon to see the golden eagles.

Directions and information: Allegheny Front Hawk Watch profile at hawkcount.org.

Before you go!  Check the wind forecast at Weather Underground, Central City, PA forecast, scroll down to the 10-day forecast and choose the “Table” tab, then click on the day you’re planning to visit for the hourly wind forecast.  Remember that a southeast wind is good.  A northeast or east wind will bring fog.

 

(photos by Anthony Bruno and Donna Foyle. See the photo captions for credits)

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Nov 02 2016

Nomads

Published by under Migration,Songbirds

Cedar waxwing adult (photo by Cris Hamilton)

Cedar waxwing, adult (photo by Cris Hamilton)

Cedar waxwings (Bombycilla cedrorum) are in town eating fruit on our trees, vines and shrubs.  Their nomadic flocks go where the fruit is and right now it’s in Pittsburgh.

These sleek, fast moving, unpredictable birds are so social you almost never see one alone.  The flocks can number in the hundreds, bouncing from tree to tree or perched high on bare branches.

Without binoculars they look like the last remaining leaves.

If you get a good look at a waxwing you’ll see a sleek bird, smaller than a robin, with a crest, black face mask, yellow tail tips, an olive brown back that fades to gray, a taupe breast and lemon yellow belly.  If you’re lucky you’ll also see the waxy red wing tips that give the bird its “waxwing” name.

Cedar waxwing adult, showing wax-tipped wings and yellow-tipped tail (photo by Cris Hamilton)

Cedar waxwing adult, showing wax-tipped wings (red) and yellow-tipped tail (photo by Cris Hamilton)

 

Its “cedar” name comes from the birds’ fondness for cedar berries.

Fruit of eastern redcedar, Juniperus virginiana (photo by Keith Kanoti, Maine Forest Service, Bugwood.org)

Fruit of eastern redcedar, Juniperus virginiana (photo by Keith Kanoti, Maine Forest Service, Bugwood.org)

 

Cedar waxwings look easy to identify but they can fool you.  They often flatten their crests and move so fast you can’t get a good look at them.  In flight they resemble starlings, and there are some odd-looking birds among them.

Cedar waxwing, immature (photo by Cris Hamilton)

Cedar waxwing, immature (photo by Cris Hamilton)

The mottled ones are immature waxwings whose body shape, black masks, and yellow tail tips are the hint to their identity.

Immature cedar waxwing eating fruit (photo by Cris Hamilton)

Immature cedar waxwing eating fruit (photo by Cris Hamilton)

 

While feeding, the flock bounces and swirls above you. Then just before they all take off they raise their voices in high-pitched Zeeee’s and are gone.  If you can’t hear the sound below, click here for the sonogram to see what you missed.  (Note: There’s a cardinal in the background of the recording. You might hear the cardinal but not the waxwings. Cedar waxwings are one of the first bird sounds we lose as we age.)

 

Though some waxwings stay all winter in southern Pennsylvania most of the nomads are on their way to the southern U.S.  They’ll leave when they run out of fruit or a cold front arrives.

 

p.s. Cedar waxwings are one of the few species whose population has increased in the past 20 years, perhaps because there’s more fruit as invasive honeysuckle spreads and we plant ornamentals in new suburbs.

(cedar waxwing photos by Cris Hamilton, photo of eastern redcedar berries by Keith Kanoti, Maine Forest Service via Bugwood.org)

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