Archive for the 'Water and Shore' Category

Nov 18 2013

Not Born Like This

Black Skimmer (photo by Steve Gosser)

Speaking of pied shorebirds as I did yesterday …  when I see American oystercatchers I’m reminded of black skimmers (Rynchops niger).  Both have bold black-and-white plumage and long beaks but their differences are striking.

Unlike oystercatchers, skimmers have very short orange legs and a beak whose mandibles are two different lengths.  They use their long lower mandible — 2-3 cm longer than the upper — to skim food from the ocean’s surface in flight.  Click here to see.

Black skimmers aren’t born like this.  At hatching their beaks are normal but by the time they fledge four weeks later their lower mandibles have grown 1 cm longer than the uppers, halfway to this striking adult appearance.

One more amazing beak fact:  Black skimmers’ beaks look fat from the side but if you see them straight on they are knife-thin like this.

The better to skim with, my dear.

 

(photo by Steve Gosser)

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Nov 17 2013

Pied

Published by under Water and Shore

American oystercatcher (photo by Gintaras Baltusis)

American oystercatchers look so unusual that it’s hard to mistake them for anything else:  big orange bill, yellow red-rimmed eyes, bold black, white and brown pattern, and thick beige legs.

Gintaras Baltusis found these two at Breezy Point, New York in late September.   Look closely and you can see they aren’t the same age.

The juvenile (below) has the same feather pattern but doesn’t have yellow eyes and his bill is still half black.

American oystercatcher (photo by Gintaras Baltusis)

 

Before Mark Catesby renamed them in 1731 American oystercatchers (Haematopus palliatus) were called Sea Pies because of their pied plumage.  Fortunately their new name describes what they eat and cannot be confused with what we eat, a casserole called a Sea Pie.

Can you think of other pie-named birds?  I know of three in North America.

 

(photos by Gintaras Baltusis)

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Nov 13 2013

Give Back, Get Back

Chidham Point, West Sussex, UK (photo from Wikimedia Commons)

Breach an earthwork like the one above, give back land to the sea, and you’ll get fewer floods.

After Hurricanes Katrina and Sandy, U.S. emergency managers and town planners are discussing giving back land to the ocean as a way to protect still-viable coastal communities.  It’s a concept called “managed retreat,” a name that conjures loss and sometimes sparks defiance in those who live at the ocean’s door.

In the U.K. they’ve recently returned more than 450 acres to the sea by breaching an earthwork just five miles from this one at Chidham Point.  The locals are excited about it.  They expect the resulting salt marsh to increase tourism.  Here’s how:

At Medmerry on the south coast of England, shingle(*) sea walls were supposed to protect towns and undeveloped land but in recent years have proved inadequate.  Stronger storms and higher tides frequently flooded the low-lying communities, especially the caravan (campers) vacation parks.  Some sections of Selsey and Bracklesham Bay are below sea level.  It wasn’t working.

In 2011 the U.K.’s Environment Agency began a managed retreat project in West Sussex.  They built four miles of new sea walls up to a mile inland around the developed areas.  They also built drainage ditches and ponds, two parking lots for visitors, and 10km of bicycle paths and horse trails.  Then they breached the earthworks and gave land back to the sea.  The resulting salt marsh buffers the ocean’s rage.

It’s also great for wildlife.  Even while construction was underway migrating water birds stopped by to visit the growing new salt marsh.  Bird watching improved immediately and is expected to get even better in the months and years ahead.  The new salt marsh will be a birding tourist destination.

Give back to the sea and get back safety and tourism.  Compromise with Mother Nature is good.

Read more about this project and see a video here at the BBC News.

 

(photo of dike at Chidham Point, West Sussex, UK, located about 5 miles from Medmerry)

(*) The British word “shingle” means the sand, pebbles, cobbles and shell-pieces that make up the beach.

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Nov 04 2013

Feed In The Middle If You Can

Semipalmated sandpiper (photo by Steve Gosser)

For two years Guy Beauchamp carefully watched the behavior of migrating semipalmated sandpipers on the tidal flats at the Bay of Fundy.  He noticed the birds were doing something that no one had ever reported.

The sandpipers on the edge of the flock kept their heads up while feeding.  They were always on the lookout for danger, especially for merlins or peregrines that could easily snatch one of them.  Meanwhile the sandpipers in the middle were more relaxed and kept their heads down most of the time.  It turns out the birds in the middle were eating different food than the ones on the edges.

The birds on the edge of the flock pecked quickly at amphipods (similar to tiny shrimp) that were easy to see.  Their sentinel behavior made it safe for those in the middle to swish their beaks back and forth and filter the tidal slurry of diatoms (algae) and phytoplankton.  Swishing behavior wouldn’t have been possible if the flock hadn’t posted sentinels.  The birds had the advantage of living in a group.

This semipalmated sandpiper is alone, feeding with his head up, and probably has an amphipod in his beak.

I’ll bet he’d like to feed in the middle of the flock if he could.

Read more about this study here in Science Daily.

 

(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 10 2013

Peregrines As A Fitness Program

Peregrine falcon at Lake Erie, Presque Isle, PA (photo by Steve Gosser)

Here’s my favorite bird patrolling Lake Erie’s shore at Presque Isle State Park, looking for a meal.

And here’s a potential food source — a flock of dunlin.

Dunlin at Lake Erie, Presque Isle, PA (photo by Steve Gosser)

The peregrine is looking for a bird that’s easy to catch.  The dunlin are sitting ducks (er… dunlin) if they stay on the ground so they fly and flock as soon as they see a peregrine.  This interaction has made dunlin more fit in the years since the peregrine population has recovered from the DDT crash.

A 2009 study at the Fraser River delta on the Pacific coast backs this up.  Peregrines never went extinct on the West Coast but they were very scarce in the 1970’s.  During this period wintering flocks of dunlin safely roosted on the sand at high tide and became fat — and a bit slower — in early winter.

The peregrine population began to recover in the 1990’s and soon found tasty dunlin meals as they migrated past the Fraser River delta in fall and spring. The dunlin quickly learned it was unsafe to roost at high tide during the day because peregrines were on patrol.  Instead they began to spend high tide flocking over the open ocean, flying and flying for three to five hours.  With this exertion they became much more fit and are now are measurably thinner in early winter, the time when peregrines are passing by.

Peregrine falcons have provided dunlin with a fitness program.  Be fit or be eaten.

Click here to read more about the Fraser River dunlin study.

 

(photos by Steve Gosser)

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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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Sep 20 2013

What’s All the Shouting About?

On vacation in Maine I saw a lot of gulls flying, posturing, and calling.

What was all the shouting about?

This video, filmed at Appledore Island, explains it all.

I wish I’d known this two weeks ago.  ;)

(video from Cornell Lab of Ornithology, featured in their September 2013 eNewsletter)

 

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Sep 16 2013

Little Blues

Published by under Water and Shore

Little blue heron (photo by Shawn Collins)

Just when you thought you’d mastered white wading birds, a wildcard shows up!

It’s the time of year for white little blue herons.  I was reminded of this when I visited Scarborough Marsh last week and encountered great egrets, snowy egrets and little blue herons, all of which were white.  Great and snowy egrets are always white, but little blues are blue … except when they’re young.

Little blue herons (Egretta caerulea) don’t breed in western Pennsylvania but juvenile birds disperse widely — they even fly north! — so it’s possible to find them outside their normal range in August and September.  Because they’re very rare in Pittsburgh I was surprised to find three at Scarborough Marsh but I should have checked the range map.  They breed in southern Maine.

With so many white wading birds how did I figure them out?  Beaks and legs!

  • Great egret:  yellow beak, black legs.  Large.
  • Snowy egret:  black beak with yellow face, black legs with yellow feet
  • Cattle egret:  yellow beak and dull yellow or dark legs. Small with short, chunky neck.
  • Immature little blue heron:  gray beak (tipped in black), yellow legs.
  • Not in Maine and Pennsylvania: the white morph of the Reddish egret: pink-and-black beak and dark legs (see photo at end).

First row of photos: Great egret + Snowy egret.
Second row: Cattle egret + immature Little blue heron.
Comparison of great egret and snowy egret (photos by Shawn Collins)

Comparison of catlle egret and little blue heron (photos by Shawn Collins)

Only the snowy egret has a black beak.   (Notice his fancy yellow feet).

The little blue is the only one with a gray beak(*), a hint that he’ll turn blue.  We won’t see him do this in western Pennsylvania because the juveniles fly south before winter.

When he’s halfway blue he’ll look very motley and match the marsh, like this one Shawn found in Texas.

Immature little blue heron with mottled blue and white (photo by Shawn Collins)

 

When he grows up you’ll never mistake him for an egret.

Little blue heron adult (photo by Shawn Collins)

He’ll be a little blue. ;)

 

(all photos by Shawn Collins)

p.s. (*) Jim Valimont points out that along the southern, Gulf, Caribbean and Pacific coasts the white morph of the Reddish Egret adds to the confusion.  Its beak resembles the immature little blue heron’s except that it’s two-tone pink and black.  It’s not found in Maine and Pennsylvania.

p.p.s  Steve Gosser contributed this photo of a white-morph reddish egret. Compare it to the first photo at top. Confusing? Yes!  But his legs are black and he only visits saltwater.
Reddish egret, white morph (photo by Steve Gosser)

 

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Sep 13 2013

Red Legs

Black guillemot in breeding plumage at Metinic Island, Maine (photo from Wikimedia Commons)

About the size of a pigeon, this northern alcid comes south to Maine for the winter.

I’ve seen black guillemots fishing close to rocky shores.  Some are still in their black-and-white breeding plumage (above). Most have changed to mottled white for winter.

Black guillemot in winter plumage (photo from Wikimedia Commons)

In either case they have bright red legs that match the insides of their mouths.

I can see their red legs through the water.

(photos from Wikimedia Commons. Click on the image to see the original)

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