Archive for the 'Migration' Category

Mar 12 2014

It’s On!

Tundra swans at Middle Creek (photo by Dave Kerr)

Despite today’s awful forecast, despite the prediction of 7oF tomorrow morning, gusty winds and up to 2″ of snow, be assured that spring is here.  The tundra swans are back!

This morning at 4:45am I awoke to the whoo-ing call of swans in flight.  I opened the window and … Yes!  a flock of tundra swans was flying over my city neighborhood in the dark.

At that moment it was 49oF with no rain and a light wind out of the east-northeast, almost perfect flying weather for birds heading northwest.  Their goal is the Arctic coastal tundra from Alaska to Baffin Island.  In the fall they typically fly 1,000 miles non-stop from Minnesota to Chesapeake Bay but they make the trip in easy stages in the spring, pausing to wait for the lakes to thaw.

“My” swans were probably heading for Pymatuning and Lake Erie where there’s not much open water yet.  Meanwhile other flocks are heading for Middle Creek where the situation is much the same.  But the birds know spring is coming. They’re heading north.

Soon Middle Creek will be filled with the spectacle of snow geese and tundra swans on the move.  Click here for information and a video.

The show is on!

(photo from Middle Creek by Dave Kerr)

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Dec 07 2013

46,600 Birds!

Red-breasted mergansers in flight (photo by LGooch on Flickr, Creative Commons License)

Yesterday Jerry McWilliams reported a single-day record of red-breasted mergansers at Presque Isle State Park: 46,600 birds!

Every fall Jerry conducts a daily waterbird count for several hours at Sunset Point.  On Friday he and Roger Donn watched “huge flocks [of red-breasted mergansers] flying in off the lake and concentrating north of Gull Point, later moving west in groups of 100 to 300 birds for the entire morning.”

Where did these birds come from and where are they going?   Red-breasted mergansers breed along the ocean and lake shores of tundra and boreal forests.  They spend the winter at the coast from Canada to Mexico or at the Great Lakes.  The birds Jerry is counting at Lake Erie have reached their final winter destination unless the lake freezes over.  If that happens they’ll move on.

How is Jerry McWilliams sure of these numbers?  For you and me the count would be quite a challenge but not for him.  Jerry’s an expert at identifying and counting birds.  He know the shapes of waterbirds, their flying style and habits.  Color hardly matters.   He uses a scope and estimates in groups.   I watched him do it for a brief time last weekend when I visited Presque Isle.  There were only 7,858 red-breasted mergansers that day and I thought that was a lot!

If you’re at Presque Isle looking for snowy owls, stop by Sunset Point and you can watch, too.

Read the count details for Friday December 6 are at this link on PABIRDS.

(photo of red-breasted mergansers in flight by lgooch on Flickr via Creative Commons License.  Click on the image to see the original)

 

p.s. This is more than twice the number of crows we’ve ever counted in Pittsburgh in the winter.

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Nov 12 2013

Sparrow Time

Published by under Migration,Songbirds

Fox sparrow and white-throated sparrow (photo by Steve Gosser)

It’s not news that migrating sparrows are back in town but it’s always news to see a fox sparrow in any setting.

Steve Gosser photographed this one (top) with another migrant, a white-throated sparrow, at Harrison Hills Park last week.

Some sparrows come to western Pennsylvania in the fall and stay all winter, including dark-eyed juncoes, American tree sparrows, and the white-throated sparrow shown above.

But fox sparrows are few and far between and right now they’re just passing through, headed for the southern U.S.

If you don’t see one before Thanksgiving you’ll probably have to wait until March to catch them on their return trip back north.

I’ve been looking, but so far no luck.

 

(photo by Steve Gosser)

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Nov 03 2013

Cormorants On The Move

DCCO_drying_sgosserDouble-crested cormorants drying their wings (photo by Steve Gosser)

These double-crested cormorants are drying their wings after diving for fish.  Are they visiting our area?  You bet.

Double-crested cormorants were on the move last week along Lake Erie’s shore.  According to Jerry McWilliam’s waterbird count, 2,125 flew past Presque Isle State Park last Sunday (Oct 27), 227 on Monday, and 680 on Tuesday. Then their numbers dropped.

When cormorants are on the move, the ducks aren’t far behind.

November may be cold but it’s a great month for watching waterfowl.

 

(photo by Steve Gosser)

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Oct 11 2013

Radar Shows Decline

Published by under Migration,Tenth Page

Southern Mississippi Sector weather radar, 9 Oct 2013, 6:38am (image from NOAA)

In one way this is very old news.  In another way it’s sadly up-to-date.

In the early days of radar surveillance, scientists learned that those mysterious blobs on the screen in spring and fall were flocks of night-migrating birds.  In 1965, as part of his graduate study at Louisiana State University, Dr. Sidney A. Gauthreaux, Jr. studied spring migration using radar images at Lake Charles and New Orleans along with his own on-the-ground counts as birds flew past his light beam or the moon.

Twenty years later, the news said that songbirds had declined.  Gauthreaux wondered if this was evident on radar so he collected data from the same two sites and compared the images from good-weather migration nights in 1965-1967 to those in 1987-1989.  In only 20 years he could see that the number of migrating songbirds had declined by 50%.   Half the number of warblers, tanagers, hummingbirds, shorebirds, flycatchers and thrushes made the trip.

That was 24 years ago.  It has only gotten worse.  I don’t know of a recent radar comparison (was there one comparing the 1980’s to 2000’s?) but our ground-based counts show that birds such as the king rail, cerulean warbler and olive-sided flycatcher are in dangerous decline now.  Just last month the eastern red knot was proposed for Endangered Species protection by US Fish and Wildlife.

Meanwhile, it seems ironic that so many people are becoming interested in birds while birds are becoming scarce, but it’s a good thing too.  The more of us that care about birds, the more likely we’ll learn what they need and work to insure their future.

 

(screenshot of NOAA weather radar, 9 Oct 2013, 6:38am EDT. Click on the image to see the current radar page.  Today’s Tenth Page is inspired by page 278 of Ornithology by Frank B. Gill.)

 

p.s.  This NOAA image shows the radar stations that were part of Dr. Gauthreaux’s study.   On Wednesday morning the weather concentrated migrants east of the Mississippi as they approached the Gulf Coast.

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Oct 08 2013

Broad-Wings Pass Veracruz

At Hawk Mountain Sanctuary, this fall’s high count of 1,338 broad-winged hawks flew by the watch on September 20.  That number sounds large but those hawks join all their cohorts from North America to pass a small strip of land between the mountains and the Gulf of Mexico near Veracruz.

The Veracruz Hawk Watch is called the River of Raptors because more than 100,000 hawks per day may pass through between the September 20 and October 25.  During the first two weeks of the watch almost all of them are broad-winged hawks.  On September 23 the broad-wing count at River of Raptors in Cardel was 354,091.

Above, a slideshow video from a 2011 birding trip to Veracruz celebrates the hawk migration and shows the birds and scenery in the area. (Sorry about the ads.)

Below, a very short video shows the “river of raptors.”  A huge kettle of hawks circles up, then tails off in a broad river to the left, heading south.  The Spanish title of this video “Vortex Cambiando a Una Linea Ancha” means “Vortex Switching to a Wide Line.”

Wish I’d been there…

 

(videos from YouTube)

 

3 responses so far

Oct 06 2013

This Is Exciting

Yellow-rumped warbler, October 2013 (photo by Shawn Collins)

They’re here!  The yellow-rumped warblers are back from Canada, on their way to the lower Ohio Valley, the southern U.S., and Central America for the winter.

Yesterday Karyn Delaney and her husband stopped counting at 100 when they found so many yellow-rumps on the Pine Tree Trail at Presque Isle State Park.  Shawn Collins snapped this one in Crawford County.

Like the first snowfall I’m excited to see my first big flock of yellow-rumped warblers in southwestern Pennsylvania.  I haven’t found a flock yet but I think I’ve heard one bird — just one — at Schenley Park.

Unfortunately, just like snow I soon tire of them.  I remember at Magee Marsh last May when my first reaction to seeing yellow-rumped warblers was “Wow!” and within an hour it was “Darn!  Another yellow-rump.”  Their abundance becomes boring.

But I haven’t seen them yet, so for the moment this bird is exciting.

 

(photo by Shawn Collins)

6 responses so far

Sep 26 2013

Thousands Of Blue Jays

Published by under Migration

Blue jay (photo by Charlie Hickey)

There are times when I ask myself, “Where have the blue jays gone?” but this is not one of them.  They’re everywhere right now.

I think of blue jays as year-round residents — and they are through most of their range — but a good number of them migrate.  Their travels, however, are poorly understood because they’re unpredictable.

Some blue jays stay, others go.  Those who leave may be young or old (not just juveniles) and an individual who stayed last winter might leave this year and not the next.  Some don’t bother to come “home” in the spring and are found nesting further south. Others come home to nest but go further south each winter.  The only hint is that blue jays store and eat acorns in the winter so the mast crop may influence their decision to travel.

Blue jays migrate during the day in loose flocks of 10 to 30 birds that often pass by hawk watches. At Cape May, New Jersey, 1,000 to 5,000 blue jays pass by each day from late September through early October.  For the really huge numbers visit Holiday Beach Migration Observatory in Amherstburg, Ontario, 23 miles south of Detroit.

Because jays are reluctant to fly over Lake Erie, they hug the northern shore and funnel past Holiday Beach as they travel southward out of Canada. Typical days in late September and early October see 30,000 to 40,000 blue jays fly by.  The highest count was 264,410 on September 28, 2001.  Observers must have wondered if any blue jays were left in Canada after a day like that!

We never see numbers like this in Pennsylvania though we get a bump up in spring and fall.  Here’s a quick visual from eBird of blue jay population fluctuation in Pennsylvania, years 2009-2013.  Click on the image to see the real graph.

Frequency of Blue Jays in PA, 2009-2013 as of 9/24/2013 (screenshot from eBird)

 

The low point for blue jays in Pennsylvania is late December to early March.

Remind me of this when I ask you where the blue jays are this winter.

(photo by Charlie Hickey. Click on the image to see the original.)

 

p.s. Here are the blue jay record-setting dates from Holiday Beach, Migration Observatory.  Click here for all non-hawk species counts.
Blue Jay Record High Counts:
Sep 26: 1986 = 49,280,  1991 = 59,650
Sep 28: 2001 = 264,410*
Sep 30: 1990 = 51,470, 1993 = 87,000
Oct 1: 2009 = 158,300
Oct 5: 2009 = 152,750

3 responses so far

Sep 25 2013

The Sun Compass

Male monarch butterfly (photo by Marcy Cunkelman)

A week ago I saw my first and only monarch butterfly of 2013.  Their sudden disappearance is both troubling and saddening.  It’s now possible to imagine a world without monarch butterflies.  We are nearly there.

Last winter’s monarch survey in Mexico showed their population was down 59%, a record low.  There have always been population fluctuations but the trend has been running low and lower since 2004.  Scientists believe that agricultural pesticides and herbicides have reduced available poison-free habitat for butterflies (similar to the bees’ problem), so this spring monarch enthusiasts encouraged people to grow safe-haven milkweed for the butterflies.  It wasn’t enough.

Each species has an intrinsic value.  If, or when, the eastern monarch butterfly goes extinct we will lose its pollination contribution, milkweed symbiosis, beauty, and the amazing adaptations that allow multiple generations to migrate from Mexico to Canada and back.

One of the adaptations that will disappear is this:  Monarch butterflies have a sun compass in their antennae.

Their antennae have light sensors that track the amount of light each day.  According to a study in 2009 by Merlin, Gegear and Reppert, this circadian clock “provides the internal timing device that allows the butterflies to correct their flight orientation, relative to skylight parameters, and maintain a southerly flight bearing, as the sun moves across the sky during the day.”  Migratory monarchs without antennae fly in aimless directions.  Monarchs with antennae always orient southwest.

The monarch’s sun compass was discovered only a few years ago.  Now there are almost no monarch butterflies to study.  The world will be a poorer place without them.

Click here for more information on the monarch’s amazing sun compass.

(photo by Marcy Cunkelman, 2008)

21 responses so far

Sep 24 2013

Longest Migration

While songbirds, hawks, and dragonflies are migrating this month there’s a bird whose journey beats them all.

The arctic tern sets long distance records in its pole-to-pole round-trip migration of 44,000 miles (71,000 km).  Since arctic terns can live 30 years, an individual can rack up a lifetime achievement of 1.5 million miles (2.4 million km).

The data behind this amazing feat was published in 2010 by the Arctic Tern Migration Project which studied arctic terns that nest in Greenland and winter in Antarctica.

To track the terns the scientists used tiny geolocator tags from the British Antarctic Survey, the same tags used to track wood thrushes.  In both studies scientists captured each bird, affixed a tag, then had to find the same bird on its breeding grounds a year later and recapture it to gather the data.  Wood thrushes don’t put up a fight but arctic terns relentlessly dive bomb their enemies to drive them away.  This study had bird hazards.

Attacking terns were not the only hazards.  Camping on an island off the coast of Greenland is no picnic.  “Our tents blew out to sea in the storm.”  Yow!

Watch this video from the Encyclopedia of Life to see the terns’ amazing migration and why it’s worthwhile for these birds to travel so far.

 

For more information, visit the Arctic Tern Migration Project at www.arctictern.info.

(video by the Encyclopedia of Life)

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