Category Archives: Water and Shore

Harlequins Warn of Mercury

Male harlequin duck (photo from Wikimedia Commons)

Some birds are canaries in the coal mine, telling us that something’s gone wrong long before we notice it.  Harlequin ducks (Histrionicus histrionicus) are performing that service in Alaska.

A 2017 study by the Biodiversity Research Institute looked for mercury in Alaska’s coastal waters by testing blood samples and molted feathers from harlequin ducks at Kodiak and Unalaska Islands. Blood samples were used because they indicate recently consumed mercury. Molted feathers show mercury when the feathers were formed a year before. 

The study found mercury in harlequins from both locations but those at Unalaska, midway in the Aleutian chain, had eight times more than those at Kodiak, nestled in the Gulf of Alaska. The study then tested the ducks’ main food at Unalaska — blue mussels — and found it there, too.

This is important news for Aleutian residents because they eat lots of seafood.  It also matters to the rest of us since Unalaska’s main port, Dutch Harbor, is the largest fisheries port in the U.S. by volume caught.  

Mercury apparently increases westward in the Aleutian chain. A 2014 study found mercury in fish above the human consumption limit at the western island of Agattu.

Where is the mercury coming from?  In the continental U.S. airborne mercury comes from coal-fired power plants and is regulated and reduced by the EPA.  It can also come from active volcanoes, obviously out of our control.

At this point scientists don’t know where the mercury is coming from, but China’s coal-fired industries are a good bet.  The prevailing wind in the Aleutian Islands originates in Asia more than six months of the year.

Winds over water in the Pacific and Bering Sea, 10 Dec 2018 (screenshot from earth “visualization of global weather conditions, forecast updated every three hours.” )

Unfortunately Alaskans can’t prevent mercury pollution that reaches them from Asia.  Meanwhile the harlequins warn of danger.

(photo of harlequin duck from Wikimedia Commons, screenshot of global winds from earth visualization website; click on the caption links to see the originals)

The Inaccessible Rail

Inaccessible Island rail (photo by Brian Gratwicke via Wikimedia Commons)

If you’ve ever gone looking for rails, you know they are usually inaccessible. They live in tall dense marsh grass and won’t come out for anything except the sound of another rail — and then only in the breeding season.

But there is in fact a truly inaccessible rail.  The Inaccessible Island rail (Atlantisia rogersi) is the smallest flightless bird in the world, extremely rare, and vulnerable to extinction.  He lives only on Inaccessible Island.

He made news in October because he cannot fly yet new DNA studies show that his ancestors, related to black rails, did fly more than 2,300 miles from South America over the South Atlantic Ocean to Inaccessible Island.  They arrived 1.5 million years ago.

This was a surprise because the island, which is in the Tristan de Cunha archipelago, is closer to Africa than to South America as shown below. (Click on the map or its caption to explore it on Google Maps.)

Location of Inaccessible Island on the globe (screenshot from Google Maps)

The island is called Inaccessible because it is.  It’s almost impossible to land on the narrow beach — most attempts fail — and the cliffs are so steep that the top is inaccessible.

Panorama of Inaccessible Island (photo from Wikimedia Commons)

The island’s walls dwarf the people exploring the beach, below. 

Inaccessible Island beach, people in the distance (photo by Brian Gratwicke via Wikimedia Commons) 

Fortunately this tour group got lucky. They were able to land and they found the rail. A member of the group, Brian Gratwicke, took these photos.

Read more about the origins of the Inaccessible Island Rail in this article from Researchgate.

(photos by Brian Gratwicke via Wikimedia Commons; map screenshot from Google maps; click on the captions to see the originals)

Who’s Faster In Level Flight?

Peregrine falcon “Buckeye” (Chad+Chris Saladin) and Red-breasted merganser (Steve Gosser)

Peregrine falcons are nicknamed “duck hawks” because ducks are one of their favorite foods.  For comparison, here’s a peregrine falcon and a red-breasted merganser.  Obviously the peregrine is more powerful.

Now imagine the peregrine is chasing the red-breasted merganser over Lake Erie.  If these two birds are traveling as fast as they can go in level flight, who would win?

In level flight (not in a dive) the red-breasted merganser is faster! 

Learn how fast these birds can go in this vintage blog post: Talk About Speed

(photo credits: peregrine falcon by Chad+Chris Saladin, red-breasted merganser by Steve Gosser)

The Finer Points of Little Gulls

Little gull, Wendy Park in Cleveland, OH (photo by Shawn Collins)

Last Sunday four of us went birding at Pymatuning State Park and found a single little gull flying among hundreds of Bonaparte’s gulls across the lake.

Little gulls are rare birds native to Eurasia who hang out in flocks of Bonaparte’s gulls in North America because the two are so similar. It takes a sharp eye to notice one.

Is there a little gull in this flock of Bonaparte’s? (photo by Shawn Collins)

Fortunately we were with Shawn Collins who has seen and photographed both species almost every winter in northwestern PA and northeastern Ohio.  After Shawn pointed out the bird, it was easy to recognize. Shawn’s photos show us the difference between the two species. 

Bonaparte’s gull (Chroicocephalus philadelphia):

“Bonnies” are very common small gulls in the Great Lakes region during fall and spring migration. They nest in trees in Canada’s boreal forest and spend the winter on the Atlantic and Gulf coasts and in the southeastern U.S. to Texas (map).

They’re best recognized by their moth-like flight style with bright white leading edges on their gray wings, seen from above and below. They have black tips on their primaries, also seen from above and below.

Notice the Bonaparte’s upperwings in the flock photo above and their underwings in two views below.

Bonaparte’s gull, Pymatuning (photo by Shawn Collins)
Bonaparte’s gull, Pymatuning (photo by Shawn Collins)

Little gulls (Hydrocoloeus minutus) are the smallest gull in the world but the size difference between little and Bonaparte’s is subtle. At this time of year the two have similar heads and backs in flight.

The real field mark for the little gull is its all-black underwings with white trailing edges.  Once you see this, you also notice that the upperwing is all pale gray — not two-tone gray-white — and there are no black tips on their primaries.

Notice these features on the little gull at top and in the two photos below.

Little gull in flight, Conneaut, OH (photo by Shawn Collins)
Little gull in flight, Conneaut, OH (photo by Shawn Collins)

Now that you know the difference between them, here are two photos with both little and Bonaparte’s gulls.  Can you tell who’s who?

Little and Bonaparte’s gulls (photo by Shawn Collins)
Little and Bonaparte’s gulls on the water (photo by Shawn Collins)

And the hardest question of all:  Is there a little gull in the flock photo above (second from top)?  

(photos by Shawn Collins)

A Big Day For Tundra Swans

Yesterday, 11 Nov 2018, was a really big day for tundra swans  in western Pennsylvania.  Flyover sightings on PABIRDS included:

All the flocks were flying southeast, heading for their wintering grounds at Chesapeake Bay and eastern North Carolina.

At Moraine State Park, 13 of us searched the sky for tundra swans when we heard them overhead.  The sky was so blue and they were flying so high that it was a real challenge to see them.  Ultimately we counted four flocks totaling 260 birds. Here’s the flight call that cued us to look up.

Tundra swans (audio by Paul Driver via xeno-canto XC72958)

Listen and look for tundra swans (Cygnus columbianus) early this week in western Pennsylvania. They usually pass through on or near Veterans’ Day.  Yesterday they were right on time.

(photo by Steve Gosser)

Been Here Seven Years

Duck Hollow’s resident common merganser has a stubby wing (photo by Dan Dasynich)

In September, Dan Dasynich saw a flightless common merganser at Duck Hollow and posted this photo of her stubby wing in the Duck Hollow Facebook group.  Her condition prompted a discussion: Since she couldn’t fly did she need to be rescued?

Common mergansers eat fish that they capture by chasing them underwater.  They don’t need to fly in order to eat and they don’t need to fly if they can swim to safety.

In September I remarked that this bird has been at Duck Hollow for at least a year, eating well and staying safe, so she didn’t need to be rescued.  Today I found proof that she’s been here for seven years, maybe more.

In a blog post from October 2011, I used Tom Moeller’s photo of her with a hooded merganser and pied-billed grebe. 

Hooded merganser, common merganser and pied-billed grebe at Duck Hollow, Oct 2011 (photo by Thomas Moeller)

That was seven years ago when she was relatively new to Duck Hollow. Though she can’t fly she’s done well for a very long time.

On Throw Back Thursday, read the first article that mentions her: Divers in a Dabblers’ World

p.s. We usually don’t see her at Duck Hollow during the summer.

(photo credits: solo merganser by Dan Dasynich, trio of birds by Tom Moeller)

Seabirds as Smart as Crows?

Antarctic skua (photo from Wikimedia Commons)

A discovery made in Antarctica two years ago has me wondering if this large predatory seabird is as smart as a crow.

The Antarctic or brown skua (Stercorarius antarcticus) breeds on barren ground in Antarctica and spends its life at sea where it uses brute force to harass other seabirds and steal their food.

Brown skuas live so far away from people that, except for a few Antarctic research stations, they almost never encounter humans.  Scientists were therefore surprised when brown skuas on King George’s Island (below) began to recognize them as individuals.

Location of King George’s Island, Antarctica from Google Maps

It all started when the Korea Polar Research Institute began studying nesting brown skuas by banding their young at the nest.  Only a couple of scientists regularly visited the nests but with each successive visit the skuas ramped up their attacks and responded from further away as the men approached.

The skuas didn’t attack everyone. They seemed to ignore people who never came to their nests. Did the birds recognize individual humans?  The scientists ran some experiments.

As shown in the video below, two scientists approached the skuas and their nest. One is a nest-intruder, the other has never bothered skua nests. The skua pair flew up to attack the humans, but when the two went separate ways the skuas only pursued the person they hate.

Brown skuas can recognize individual humans that cause them trouble.  Crows can do it, too. Are Antarctic skuas as smart as crows?

 

Read more about the skuas here in Discover Magazine.  Read about crows recognizing our faces at this link.

(photos from Wikimedia Commons; map location of King George’s Island from Google Maps; click on the captions to see the originals)

Spinning Like A Top

Red-necked phalarope, September 2011 (photo by Andy Reago & Chrissy McClarren via Wikimedia Commons)

You would think that all shorebirds live at the shore but not this one.  The red-necked phalarope (Phalaropus lobatus) spends most of his life at sea, spinning like a top.

Phalaropes live inland from June through August while they’re breeding in the sub-arctic northern hemisphere but most of the year — November through March — they’re out to sea on the tropical ocean.  Their food is on or near the water’s surface.

Phalaropes feed by swimming in tight circles, rapidly picking tiny insect larvae, crustaceans, and mollusks from the water.  Their feet are specially equipped for swimming. They have lobed toes like coots.  (“Phalarope” is Ancient Greek for “coot toes.”)

In winter red-necked phalaropes don’t have red necks. Right now they’re wearing gray “basic” plumage, shown above, as they migrate to their final destinations in the southern hemisphere. Western birds take an inland route through the western U.S. but you probably won’t see one in the east. Except for a few stopovers at the Great Lakes, the eastern population flies immediately to the Atlantic Ocean. 

If you really want to see red-necked phalaropes in beautiful breeding plumage you’ll have to wait for spring.  Sparky Stensaas filmed this group feeding at their breeding grounds in Churchill, Manitoba, Canada.

Red-necked Phalarope spin feeding Churchill, Manitoba, Canada from Sparky Stensaas on Vimeo.

Look how fast they spin!

(photo from Wikimedia Commons; click on the caption to see the original. video by Sparky Stensaas on Vimeo)

Living In The Wind

Hudsonian godwits (Limosa haemastica) breed on remote tundra and sedge meadows in Canada and Alaska, then spend the winter as far south as the tip of South America.

To make this long journey they assemble in flocks in August on wet prairies and mudflats where they use their long upturned bills to probe for invertebrates and plant tubers.

Since their food is found in wide open places, Hudsonian godwits spend their lives in the wind.  I hadn’t thought about this until I searched for videos and hear the wind on every soundtrack.

At top, Hudsonian godwits fly in slow motion in the moaning wind.  Below a flock of 2,500 assembles at James Bay, Canada in lots of wind.

Occasionally a lone Hudsonian godwit is found during migration, like this one at Bowdoin National Wildlife Refuge in Montana.  Even here it’s windy.

(videos from YouTube; click the YouTube logo to see the originals)

Egrets Fly North Before South

  • Great egret in Montour County, August 2018 (photo by Lauri Shaffer)

Great egrets (Ardea alba) are southern and coastal birds with only a few breeding sites north of Mason-Dixon. However, those few sites don’t account for the high number of egrets we see outside their breeding range in August.

As it turns out, great egrets disperse widely after they’re done breeding.  Many move north before flying south for the winter.

Lauri Shaffer posted these photos on Facebook with the comment:  “Love August when the Great Egrets finally make it north to Montour County!” (Pennsylvania)

I wish great egrets would stop in Pittsburgh.

photos by Lauri Shaffer at birdingpictures.com