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.
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?
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.
Great egret in Montour County, August 2018 (photo by Lauri Shaffer)
(photo by Lauri Shaffer)
(photo by Lauri Shaffer)
(photo by Lauri Shaffer)
(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)
In August and September young puffins, called pufflings, make their first flight from their nesting islands in Newfoundland. Guided by the light of the moon they head for the open ocean. Unfortunately, when it’s foggy or moonless they’re confused by outdoor lights and head inland where they become stranded and die.
Years ago Juergen and Elfie Schau of Germany noticed stranded pufflings near their summer home at Witless Bay, Newfoundland so they rescued them and returned them to the sea. Soon their neighbors joined them and in 2011 the project grew into the Canadian Parks and Wilderness Society’s (CPAWS) annual Puffin and Petrel Patrol.
Travelers from around the world come to Witless Bay in late summer to help rescue baby puffins. The stranded birds are captured in small nets, placed in carriers, and released in the morning when the birds can see where they need to go — out to sea.
The Youghiogheny River is famous for whitewater rafting near Ohiopyle but there’s a tributary downstream where white water is bad.
On the GAP Trail north of Buena Vista — near marker 121 — you can hear a rushing waterfall before you see it. When you reach its location it’s not a pretty sight. The waterfall stains everything white.
Early this month I looked at the water and its outflow in the Youghiogheny River and discovered that the water is clear and colorless, though it leaves a white residue on everything it touches.
Here are some closer looks.
The water is clear because it’s acidic. The residue is from abandoned mine drainage (AMD), a problem that pollutes more than 2,500 miles of Pennsylvania rivers and streams.
As water from the abandoned mine travels downhill it blends with clean water that raises the pH (i.e. lowers the acidity). At some point the diluted mine water isn’t acidic enough to dissolve aluminum sulfate so the aluminum precipitates out as white residue.
Every fall this bird performs an amazing feat of physical endurance. It flies non-stop over the ocean for 2,500 miles.
The whimbrel (Numenius phaeopus) is a long distance migrant that occurs on every continent except Antarctica because it breeds in the far north and winters in the southern hemisphere.
Most North American whimbrels spend the winter in coastal South America. To get there, some travel the western route down the Pacific Ocean to Columbia, Ecuador, Peru and Chile.
Others take an eastern route, flying across northern Canada in mid-July to spend two weeks fattening up on the shores of the U.S. and Canada. Then they launch over the Atlantic and fly non-stop to Venezuela, the Guianas and Brazil. What’s the air distance from Cape Cod to Venezuela? 2,500 miles.
Late July doesn’t look or feel like autumn but fall migration has already begun.
Shorebirds are some of the earliest species to start their journey south. Last weekend brought a good assortment to Gull Point at Presque Isle State Park in Erie, PA. Here are a few of the migrants we would have seen if we’d been there.
American Avocets (Recurvirostra americana), above, raise only one brood per year and will leave the breeding grounds immediately if their nest fails. Avocets are always a treat in Pennsylvania because they breed far west of here and could easily bypass us if they wanted to. Instead, some fly to the east coast before moving south. Steve Gosser found a pair hanging out at Conneaut, Ohio in July 2013. (The bird with the black head is a Bonaparte’s gull. He’s also migrating.)
Sanderlings (Calidris alba), below, nest on the tundra in high arctic Canada, mostly north of the Arctic Circle. These small birds have one shot at breeding so if it doesn’t work they form flocks with other failed breeders in late June and move south in July.
Short-billed dowitchers (Limnodromus griseus) breed from Hudson Bay to western Labrador and in northern Manitoba and Alberta. Failed breeders leave the breeding grounds in late June while successful females depart in early July followed by males later in the month. Juveniles leave in August. Once they start passing through we’ll see short-billed dowitchers in Pennsylvania for several weeks.
The lesser yellowlegs’ (Tringa flavipes) lifestyle dictates when each family member leaves the breeding grounds (Alaska to Hudson Bay) for their winter home (primarily in Suriname). Successful females head south in June as soon as their eggs hatch and the young walk off the nest. The males protect their chicks until they fly then head south, too. The juveniles form flocks and fend for themselves until they decide to leave.
Bird Rock is one of many cliffs at Cape St. Mary’s but it’s unique because it’s separated from the mainland by a deep chasm only a few feet from the trail’s end. The birds are safe from land-based predators yet we could see them easily.
The main attractions are 24,000 northern gannets (Morus bassanus) who spend their lives on the ocean but return to Cape St. Mary’s every spring to breed with the same mate at the same nest. Almost as large as bald eagles, their wingspan is 5.75 feet but they don’t weigh as much. I love them for their size, sleek beauty, and their ability to plunge-dive at 50 mph to catch fish in the sea.
From the Visitors Centre we walked the trail across the barrens to get to the viewing area.
Pretty soon we could see the nesting cliffs. The white areas are all gannets.
Near the trail’s end, Bird Rock is in the foreground.
Here’s what we saw when we got there. This 2011 video below (not my own) captures the sights and sounds of the colony. The only thing you’re missing is the fishy smell of guano. It was filmed when most of the birds were still courting, wagging their heads and touching bills. When we visited last week they were further along. Some chicks had already hatched.
The gannets hunt far and wide for fish to feed their chicks. Just around the corner from Cape St. Mary’s in Placentia Bay there are loads of fish near Saint Bride’s. This YouTube video from 2017 (not my own) shows what I love most about gannets. They dive straight down to the sea!
p.s. The white spouts aren’t whales. They’re the splash-back from the gannets’ precision dives.
(first photo from Wikimedia Commons; click on the image to see the original. videos from YouTube. All other photos by Kate St. John.)