Archive for the 'Migration' Category

Sep 12 2013

No Food, No Water

Mount Desert Rock (photo by krzdweasel, Creative Commons license)

Twenty miles off the coast of Mount Desert Island is a tiny granite outcrop called Mount Desert Rock.  On a clear day you can see it with binoculars from the mountains of Acadia National Park. It looks like an improbable ship, taller than it is long.

Only 3.5 acres in size, Mount Desert Rock holds three buildings and a lighthouse just 17 feet above sea level. During winter storms and hurricanes the ocean washes over the island and punishes the buildings. The boathouse was swept away during Hurricane Bill in 2009. Isolated and exposed the Rock stands alone. Click here to see how small it is.

Map showing location of Mount Desert Rock (image from Wikimedia Commons)

Whale watching tours from Bar Harbor sometimes circle the Rock.  That’s how I’ve come close but never landed.  The Rock has no harbor so even those authorized to land can only do so when the sea is calm.

Lighthouse keepers and their families used to live year-round on the island, sheltering in the lighthouse during storms.  Since 1998 the College of the Atlantic has had whale and seal study crews posted there on temporary assignment, but they leave before a storm.

No matter who is stationed there, they must survive on food and water shipped from the mainland.  Rainwater is collected in a cistern under the keepers’ house but it’s undrinkable.  Nothing can grow there because the ocean washes away the topsoil in every storm.  And there is noise: The foghorn blares every 30 seconds.

When the weather is right, songbirds take a shortcut across the Gulf of Maine during fall migration from Nova Scotia to Maine.  From the whale watch boat I’ve seen ruby-throated hummingbirds and robins pumping their way past the Rock to Mt. Desert Island 20 miles away.  It’s scary to think they are over open water, sometimes fighting the wind, spending themselves to make landfall on the shores of Acadia — or else they will die.

Fly safe, little birds.  The Rock is no place to rest.  No food.  No water.

(photo by “krzdweasel” via Flickr, Creative Commons license.  Click on the image to see the original. Map from Wikipedia.)

2 responses so far

Sep 11 2013

On The Move

Published by under Migration,Songbirds

Swainson's thrush (photo by Shawn Collins)

Last night in Bath, Maine I heard thrushes migrating in the dark.  As they fly they make short contact calls to keep the flock together. Among the calls, I was able to identify two species.

The first call was plentiful and sounded like the single note of a spring peeper.  Those were Swainson’s thrushes (above).  Click here to hear the peep sound at the beginning of the recording.

The second sound was less frequent.  There were fewer of this species, their call note lasted longer and descended roughly.  By listening at the Macaulay Library online I determined they were gray-cheeked thrushes (below).  Click here to hear.

Gray-cheeked thrush (photo by Shawn Collins)

 

Last night the birds were on the move while the weather was good.  Today will be hot.  Tonight will be stormy.

 

(photos by Shawn Collins)

No responses yet

Aug 19 2013

Western Hummer Season

Published by under Migration,Quiz

Mystery Hummingbird #1 (photo by Steve Valasek)

Last week Scott Weidensaul reminded Pennsylvania birders that with hummingbird migration underway we might — just might — see a rarity at our feeders.

He wrote, “PABIRDers will recall that last fall and winter we documented an astounding 94 western hummingbirds of four species in Pennsylvania, and that was probably the tip of the iceberg.”

In honor of Western Hummer Season I’ve made a quiz with a twist. These recent hummingbird photos were all taken outside of Pennsylvania by former Pittsburghers.  Some of these birds can be found in Pennsylvania, one cannot, and one of Pennsylvania’s rarities isn’t pictured here at all.

Can you identify these hummingbirds?  (starting with Mystery #1 above)

Experts will know what they are.  The rest of us can appreciate the beautiful photos.  Don’t feel bad if you can’t identify them — I couldn’t without looking them up.   Answers are in the first Comment.

Mystery Hummingbird #2:
Mystery Hummingbird #2 (photo by Steve Valasek)

 

Mystery Hummingbird #3:
Mystery Hummingbird #3 (photo by Steve Vlasek)

 

Mystery Hummingbird #4:
Mystery Hummingbird #4 (photo by Steve Valasek)

 

Mystery Hummingbird #5:
Mystery Hummingbird #5 (photo by Chuck Tague)

 

Keep your hummingbird feeders full and watch for unusual birds this fall.  The hint may be just a slight color difference.

After October 15, any hummer you see in Pennsylvania is a western rarity to report on PABIRDS or to Bob Mulvihill at the National Aviary (412.323.7235).

 

(all photos by Steve Valasek, except for the photo with a flower which is by Chuck Tague)

p.s.  See Rob Protz’ comment for the western hummer species I forgot to mention…

8 responses so far

Aug 03 2013

Visiting Shorebirds

Marbled godwit at Conneaut Harbor, Ohio (photo by Steve Gosser)

Shorebirds are migrating but we’re not likely to see them in Pittsburgh because we don’t have a shore. However there’s an excellent place north of us that does:  the harbor at Conneaut, Ohio.

Conneaut’s harbor was formed where Conneaut Creek flows into Lake Erie.  The lake’s waves can be rough so the harbor has been sheltered by two breakwaters.  These allowed the creek (and probably the harbor dredge) to deposit a sand spit and mud flat so extensive you can park on it.

Visiting shorebirds feed at the water’s edge and rest on the sand.  Sometimes they’re so close you have to back up to see them with binoculars!

The harbor is more than two hours away but the trip is well worth it.  Steve Gosser photographed this marbled godwit there in July.

Click here for a map and the harbor’s eBird checklist.  The best place is called the “sand spit” on the map.

More shorebirds coming.  Visit them at Conneaut.

(photo by Steve Gosser)

One response so far

Jun 26 2013

I’m On A Tight Schedule

Published by under Migration,Peregrines

Island Girl, 2009 (photo by Bud Anderson from the Southern Cross Research Project)

Late June is an intensely busy time for peregrine parents in North America’s mid latitudes. If their nests were successful they have young about to fledge or already on the wing who must become independent in just four to eight weeks.

If you think that’s fast, consider the life of an arctic peregrine.

Island Girl, pictured above, is an arctic peregrine tagged with a satellite transmitter in southern Chile in 2009 by the Falcon Research Group. They’ve tracked her migrations every year in amazing detail, able to determine latitude, longitude and altitude of her roosts and see the neighborhood where she chooses to sleep via Google Earth.

Island Girl nests on Baffin Island, Canada and spends November to April on the coast of southern Chile. To do this she travels nearly 17,000 miles per year.  This spring she left Chile on April 17 and arrived at her eyrie in Canada on June 3, covering 8,868 miles in only 48 days. She got home early.

Here’s a screenshot of her trip.  (Click on it to see the real map.)  This is the feat of an athlete!
Screen shot of Island Girl's migration tracking map, Spring 2013 (from Southern Cross Peregrine Project)

Now that she’s on her breeding grounds Island Girl has a very compressed schedule. She arrived on June 3 (the day Silver Boy fledged) and absolutely must leave in late September.  Winter comes quickly on Baffin Island so Island Girl always leaves between September 20 and 24.  Always.

This gives her about 111 days to court, lay eggs, incubate, raise nestlings, and teach fledglings.

Her schedule probably looks like this:

  • Courtship and egg laying:  14-18 days, June 3 to June 19.  This is the most optimistic schedule, assuming an established mate, an established territory and no intruders.
  • Incubation: 33-35 days, June 19 to July 23
  • Nestling phase, 39 to 45 days, July 23 to September 3
  • Fledged young dependent on parents, 4-8 weeks,  September 3 to October 1 or October 29.

There’s barely time to fledge young and begin to teach them before she has to leave for Chile. In fact her kids might leave with her and learn to hunt while traveling.

Arctic peregrines are certainly on a tight schedule!

 

(Island Girl photo by Bud Anderson and Spring 2013 migration tracking map from the Southern Cross Peregrine Project, Falcon Research Group Click on the images to see the originals)

3 responses so far

May 16 2013

A Two Week Trip

Wood Thrush (photo by Steve Gosser)

I heard my first wood thrush this year in Schenley Park on April 24 but the real influx didn’t occur until May 8.  On that morning the wood thrush population in the park doubled overnight.

Each bird made the trip from eastern Honduras or Nicaragua in 13-15 days.  We know where they spend the winter, how long it takes to get here, and the routes individual birds take thanks to ongoing migration studies by Bridget Stutchbury’s University of York team, begun in 2007.

Stutchbury pioneered the use of tiny geolocators, smaller than a penny, that record only two things: the universal date-time (UTC) and the amount of light.  Crunch a year of data and you get sunrise, sunset and day length which reveal the bird’s location each day.  To collect this data, the tagged bird had to return from migration (a 60% chance) and be re-trapped to remove the geolocator (90% success rate, skill required!).

Now that the team has tracked some individual wood thrushes for several years they’ve found that:

  • Wood thrushes fly more than 300 miles a day on migration.
  • In the fall, they may stopover in the southern U.S. or the Yucatan for one to four weeks before proceeding to their final destination.
  • They dawdle in the fall but return two to six times faster in the spring because they barely stop at all.
  • Wood thrushes who live near each other in Pennsylvania don’t scatter when they get to Central America.  A single breeding population from Pennsylvania spends the winter in a narrow band of forest in eastern Honduras and Nicaragua.  If that forest disappears, so will all those wood thrushes.
  • Wood thrushes don’t use local weather cues to determine when to head north.  Instead they have built in endogenous triggers similar to long-distance shorebirds.  Some of their triggers are so accurate that individuals begin northward migration on the same day every year.
  • Though wood thrushes tend to have a favorite departure date they don’t take the same route every year.  The route depends on weather and fitness.
  • First year birds tend to leave the wintering grounds later than those who’ve made the trip before.

So I’ll bet those early wood thrushes are the older, experienced birds who left Central America around April 10.  Two weeks and more than 2,000 miles later they arrived in my neighborhood on the day the rest of the flock left the wintering grounds.

Awesome!

 

For more on these studies, click here for background on the 2010 report and here for their 2012 findings.

(photo by Steve Gosser)

One response so far

May 07 2013

Important Rest Stops

Published by under Migration

Bay-breasted Warbler (photo by Chuck Tague)

Birders flock to Magee Marsh, Ohio in May because the birds do, too.  For us it’s exciting to see them so close. For them it’s an important rest stop on their long journey from Central or South America to Canada.

Songbirds migrate overnight and stop before dawn to rest for the day. They may be leisurely in the fall but they make the journey faster in spring.  This bay-breasted warbler travels from Panama or northern South America to Canada, a journey of at least 2,400 miles, and he does it in as little as 17 days.  His longest leg is more than 500 miles non-stop across the Gulf of Mexico.

Rest stops are key.

Imagine you’re driving each night on a long distance journey.  From experience, or because you’re traveling in a group (i.e. flock), you’ve picked the rest stops in advance.  You’re on a tight schedule and you’re not going to stop often.  A few of the rest stops are the last food and fuel for hundreds of miles.  No problem.  You’ve been there before and you know those places are good.

But what if you arrive one night and a crucial rest stop is gone… destroyed?  No gasoline, no food and you’re nearly out of both.   You have no idea where to find a substitute and you’re already tired.  If you’re a bird, this emergency can kill you.

That’s why the warblers at Magee Marsh don’t seem to care about people. They’re hungry and they don’t have much time.  They’re fueling up so they can leave tonight for Canada.

And that’s why the National Audubon Society, the American Bird Conservancy, the Nature Conservancy, and the Western Hemisphere Shorebird Reserve Network  are all working to preserve stopover sites for migratory birds.

 

(photo by Chuck Tague)

One response so far

May 05 2013

On Erie’s Southern Shore

Published by under Migration,Songbirds

Cape May warbler (photo by Bobby Greene)

Cape May warblers are some of the many wonderful birds at Magee Marsh, Ohio this year.

Other highlights on the south shore of Lake Erie include:

  • An eye level look at a cerulean warbler,
  • Discovering that a brown lump in a field was an American golden-plover when he turned around,
  • Finding two soras in the reeds … and then they mated,
  • Seeing a great horned owl nestling with pretty face feathers,
  • And watching a sora cross the road. He made himself into a ball so he looked like a very slow, round muskrat without a tail (was this camouflage?) and risked his life by walking slowly in front of traffic.  Fortunately all the drivers were birders and we stopped to stare and spare his life.

Glad to be here!

(photo by Bobby Greene)

No responses yet

Apr 07 2013

Major Migration In The Ohio Valley

Published by under Migration

NWS Central Great Lakes radar, 4/7/13, 4:18am (image from the National Weather Service)

The wind was finally from the south overnight.  This morning’s pre-dawn weather radar shows a little rain and a lot of birds.

The blue circles over the cities are radar locations picking up lots of small bodies flying north.  Yes, birds!

If you live in any of these blue circle zones, today would be a great day to go birding — unless it’s storming.

p.s.  There was not a lot of migration activity on the East Coast.  Their wind was probably unfavorable.

(radar image from the National Weather Service Central Great Lakes. Click on the image to see the most recent view.)

6 responses so far

Mar 27 2013

Sniffing Their Way North

Gray Catbird (photo by Alan Vernon from Wikimedia)

Conventional wisdom says that birds can’t smell anything, but this isn’t so.

Did you know they use their sense of smell to guide them on migration and that it’s more important for navigation than magnetic field detection?

Back in 2009 the Max Planck Institute of Ornithology ran an experiment to see which mattered  more.  During fall migration they captured 67 gray catbirds and put tiny radio transmitters on them.  48 were captured at the Princeton field station, 19 were captured in Illinois and delivered overnight to New Jersey.  This presented the Illinois birds with a big navigational challenge.

All of the birds were fitted with tiny radio transmitters and divided into three groups.  One third had scramblers to impair their magnetic field sense, one-third had a temporarily impaired sense of smell, one third had no impairments.

When released to continue their migration, where did the birds go?

The juvenile birds performed as expected.  Having never made the trip before they had no mental map so they flew due south to Cape May and had to cross Delaware Bay at its widest point.

Unimpaired adults and those with an impaired magnetic sense used their mental maps and sense of smell to fly southwest and avoid Delaware Bay.  Even the “blown off course” Illinois birds flew west or southwest to correct for their new location.

But those who couldn’t smell anything were a little lost.  The adults with mental maps fell back on their original inborn guidance system and flew due south.  So, yes, their sense of smell matters a lot more than we expected.

Next month gray catbirds will arrive in Pittsburgh from their winter range in Florida, Cuba and the lands surrounding the Gulf of Mexico.  When they get here, you can be sure they sniffed their way north.

I wonder what they’re smelling…

 

(photo by Alan Vernon from Wikimedia Commons.  Click on the image to see the original)

No responses yet

« Prev - Next »

Bird Stories from OnQ