In 2011 crane watchers in Homer, Alaska noticed that a single Canada goose was convinced he was a sandhill crane. How did this happen? And can it be undone?
As described by Encyclopedia Britannica, imprinting is a form of learning in which a very young animal fixes its attention on the first object it sees, hears, or is touched by and thereafter follows that object.
Imprinting is especially important for nidifugous birds — species that walk away from the nest shortly after hatching — because they must immediately follow their mother in order to survive. They imprint by sight and the lesson lasts a lifetime. If the first thing they see is their mother or another member of their own species, life is good. If not, they grow up believing they are another species and will never find a mate.
Imprinting happens at different times for different species so wildlife centers use surrogacy techniques, described here at the Wildlife Center of Virginia, to insure that baby birds don’t imprint on humans. If they do they cannot be released in the wild.
Birds use filial imprinting but there are other forms. Studies have shown that we humans prefer the first computer software we use and then compare all new software to that first and favorite app. It’s a form of imprinting called Baby Duck Syndrome. “I don’t like this; it doesn’t work like Microsoft Word.” Quack! Quack!
As for the Canada goose in the video, observers speculated that the bird’s mother laid his egg in sandhill crane nest. When he hatched he saw a sandhill crane and imprinted on the wrong species. He’s the victim of an imprinting error.
(video by Nina Faust on YouTube. photos from Wikimedia Commons; click on the captions to see the original)
Nesting season began last month for this pair of Bermuda cahows when the female laid her single egg on 10 January 2019. The parents are now taking turns at incubation duty. They expect the egg to hatch in early March.
Climate change is giving us extreme weather, melting glaciers and rising seas. It’s not the first time we humans lived through this but the last event was during the Stone Age and nobody wrote it down.
During the last Ice Age England was connected to Europe. As the glaciers receded people moved to the land between. Dogger Bank was the highest ground, about 100 feet above sea level.
100 feet sounds like a safe height, right? Nope. The glaciers kept melting. Dogger Bank disappeared 8,200 years ago.
The nesting season began for this Bermuda cahow when she returned to her nest burrow on Wednesday 9 January 2019 at 11:55pm (almost midnight). By 1am she had laid her single egg. Click here for a video.
Cahows or Bermuda petrels (Pterodroma cahow) live on the open ocean and only come to land on dark nights during the nesting season, placing their nests in underground burrows on small inaccessible islands to protect them from predators. Humans used to be one of those predators. We ate them. By 1620 cahows were presumed extinct.
When cahows were rediscovered in 1951 there were only 18 nesting pairs on Earth, but thanks to the conservation efforts of David B. Wingate and the Cahow Recovery Project there are now more than 135. Most of them are on Nonsuch Island where many burrows are man-made to provide additional nesting sites. This burrow has a camera.
The pair that “owns” this burrow came back in November to refurbish the site, court and mate. In December they returned to the sea. Then on Wednesday the female returned to lay her egg and begin incubation. Her mate will arrive and take over incubation so she can go back to the ocean to eat.
Last weekend in Virginia Beach I saw swamp rainbows for the first time.
I was birding at First Landing State Park, one of the last places in town that still has a bald cypress swamp, when I noticed that the water between the trees was colored red, orange, yellow, green, blue and purple. The rainbow colors moved as I walked.
Where I come from in western Pennsylvania, a rainbow on water is a bad thing. It means there’s oil on the water’s surface and it got there because people drilled and spilled. But these swamp rainbows are natural.
The water’s calm surface has a thin film of plant oils and pollen that reflects and refracts light. The resulting rainbows are seen better in winter because the sun is so low.
Last month someone else noticed the rainbows at First Landing and posted a photo on Reddit that went viral and was covered by the BBC.
Click here to see additional photos and read more about rainbows in the swamp.
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.
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.
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 earthvisualization website; click on the caption links to see the originals)
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.)
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.
The island’s walls dwarf the people exploring the beach, below.
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.
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!
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.
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.
“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.
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.
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?
And the hardest question of all: Is there a little gull in the flock photo above (second from top)?