When Europeans explored the Pacific they sometimes named islands for the day they found them. Thus Easter Island (Rapa Nui) was named by Dutch explorer Jacob Roggeveen who encountered it on Easter Day 5 April 1722 and Christmas Island (Kiritimati) was given its English name by Captain James Cook on Christmas Eve 1777.
Easter Island is best known for its nearly 1,000 stone statues, moai, created by the Rapa Nui people. Kiritimati (pronounced “Ki-rismas” in the local language) is so remote that it was used for nuclear bomb tests 60+ years ago. Today the entire coral atoll is a wildlife sanctuary.
Christmas shearwaters (Puffinus nativitatis) are pelagic birds that nest on remote Pacific islands (map) and were named for their largest breeding colony at Kiritimati, Christmas Island.
Three weeks ago frogs were singing and laying eggs in the vernal ponds of southwestern Pennsylvania. Many of the eggs have hatched by now. What do the tadpoles do next? This video from a remote lake on Vancouver Island, BC, Canada provides a hint.
Maxwel Hohn spent four years filming a tiny migration we never see. Every morning western toad tadpoles (Anaxyrus boreas) swim from their nighttime shelters to feeding areas in the lake, then back again to hide at night. The result is his award-winning 8+ minute video: Tadpoles: The Big Little Migration.
Our eastern American toads (Anaxyrus americanus) are closely related to western toads so I wonder if they do this, too.
Meanwhile, if the video wasn’t amazing enough for you, here are two more amazing things about tadpoles and toads:
Don’t worry that our tadpoles won’t survive the freezing temperatures this morning in eastern North America. Even if the ponds freeze, tadpoles are able to overwinter under ice. See photos at What’s Under the Ice? Wow! Winter Tadpoles from Oakland Twp, Michigan.
Do you know where North America’s toads came from? South America. And they didn’t walk! “Based on DNA sequence comparisons, Anaxyrus americanus and other North American species of Anaxyrus are thought to be descended from an invasion of toads from South America prior to the formation of the Isthmus of Panama land bridge, presumably by means of rafting. — from the Wikipedia description of the American toad.
There’s a Rule Of Thumb that says: Pittsburgh area osprey return from winter migration around St. Patrick’s Day.
This year the earliest eBird reports for southwestern Pennsylvania show osprey in Beaver and Butler Counties on 20 March 2021 and arriving this week along the Ohio River and at many lakes.
I haven’t seen an one yet so my goal this weekend will be to find an osprey, maybe at the Duquesne nest site.
Native from Florida to Argentina, the snail kite (Rostrhamus sociabilis) is a gregarious bird of prey that eats only one thing: freshwater snails in the genus Pomacea. Its beak is specially shaped to do so.
The Snail Kite’s slender, deeply hooked, sharp-tipped upper mandible permits it to cut the columellar muscle of Pomacea snails and remove soft tissues from the shells. The arc of the upper mandible approximates the inner spiral of the snail’s shell.
In the old days before humans took over Florida’s landscape, snail kites ranged over half the state, but we drained and diverted more than 50% of Florida’s wetlands, the snail kite population crashed and was listed as Endangered in 1967. Twenty years ago, from 2000-2007, their population dipped so low that scientists feared they would go extinct in the U.S. Then a curious thing happened. Their food supply changed and the kites changed so they could eat it.
Before this century the snail kite’s main food was the native Florida apple snail (Pomacea paludosa) but an invasive species, the island apple snail (Pomacea maculata), arrived in 2000 and began to spread in Florida’s lakes and water management areas.
When the island apple snail first arrived in Florida the snail kite population dropped but less than a decade later the population began increasing. Did the birds initially have a tool problem? Were their beaks too short to get at the snail inside the larger shell? A recent study from the University of Florida indicates this was probably the case. Since 2007…
Researchers found that the birds with bigger bills were surviving, and their offspring were inheriting the bigger bills. …
“We found that beak size had a large amount of genetic variance and that more variance happened post-invasion of the island apple snail. This indicates that genetic variations may spur rapid evolution under environmental change,” Fletcher said.
We think of evolution as a very slow process but for the snail kite it happened quite fast. Those with longer bills survived. Nowadays they easily eat island apple snails.
Goose barnacles often attach themselves to old wood and float from tropical seas to northern shores including the shores of Britain. The barnacles pictured here and in the video below are Lepas anatifera. Their bodies are supported by a long, flexible stalk (a peduncle) that resembles a goose neck.
These fascinating crustaceans are goose barnacles. They live in unmistakably dense colonies, often attaching themselves to marine objects. They occasionally get washed up around our shores. ??
Goose barnacles and barnacle geese have similar names because people linked them to explain where the geese came from.
Every fall barnacle geese (Branta leucopsis) migrate to Britain and the east coast of the North Sea where they spend the winter. Those in Britain arrive from their breeding grounds in Greenland.
During the day barnacle geese will often feed in fields before taking off en masse, in spectacular aerial displays to return to their roosting sites for the night. ??
Nowadays that story sounds silly but we shouldn’t be too smug. We still create stories to explain things we don’t understand and spread them quickly on the Internet. In the future our fantastical stories will sound silly, too. I can think of a few about the coronavirus.
(photos from Wikimedia Commons; click on the captions to see the originals)
Though it looks something from outer space this unearthly pink blip is rising from a microbial mat inside the Middle Island Sinkhole (45.192515,-83.327195) in Lake Huron, about 12 miles from Alpena, Michigan.
Great Lakes sinkholes were found by accident in 2001 while looking for shipwrecks and have been studied for only 20 years.
Some, including the Middle Island Sinkhole, have vents that add water to the lake. This water is warmer than the nearby lake, has lower oxygen, 10 times the chloride, 100 times the sulfide, and a higher concentration of bacteria. The water looks very green.
p.s. Fish live in some parts of the sinkhole. The photo below shows a burbot resting on a rock. If you don’t see the fish, click on the photo for a hint.
Many plants that grow near water disperse their seeds by riding the water wherever it goes. Fabulous among this group are tropical plants whose drift seeds cross the ocean.
The monkey-ladder vine or sea bean (Entada gigas), above, produces hard-covered heart-shaped seeds that contain an air pocket to keep them buoyant. Seeds from the Caribbean and Central America wash into the ocean and float on the Gulf Stream. Some make landfall 15 months later on the shores of Scotland.
They can also be found at Orkney as seen in this video from BBC Winterwatch.
Where the land meets the sea, a whole host of treasures are waiting to be discovered – brought here from across the globe by swirling ocean currents. Join @peediepuss as he shares his discoveries from Orkney’s beaches. ??#Winterwatch ?? pic.twitter.com/C06tap0Zr3
If you want to see a rare gull that breeds in Europe or the arctic, February is the best time in Pittsburgh.
Gulls need open water for food and shelter so when ice forms they have to leave. Arctic breeders move to openings in the sea ice (polynyas) or fly south along the coasts or to the Great Lakes. When it’s very cold the Great Lakes freeze by February and the gulls move further south. That’s when they find Pittsburgh.
Though our city is 300 miles from the ocean a few gulls stay here year round. Several dozen herring gulls (Larus argentatus) breed on our rivers and a few non-breeding ring-billed gulls (Larus delawarensis) spend the summer. In winter they are joined by hundreds more.
Last week a single lesser black-backed gull (Larus fuscus) appeared at the gull roost where the Allegheny meets the Ohio. This species breeds on the coast of Europe and Iceland — and possibly now in Greenland and maritime Canada — but Pittsburgh is west of its normal range.
According to the Great Lakes Total Ice Coverage Map from 30 Jan 2021, the Toledo end of Lake Erie is fully iced up and it’s pretty thick now at Cleveland. If he was staying near Cleveland he would have to leave.
Red leaves at Duck Hollow, 29 Nov 2020 (photo by Kate St. John)
Nine Mile Run at Duck Hollow, 29 Nov 2020 (photo by Kate St. John)
Pretty, Invasive, Glossy buckthorn. Duck Hollow, 29 Nov 2020 (photo by Kate St. John)
Fox squirrel in box elder, Duck Hollow, 29 Nov 2020 (photo by John English)
Killdeer, Duck Hollow, 29 Nov 2020 (photo by John English)
Duck at Duck Hollow, 29 Nov 2020 (photo of mallard by John English)
Snow on the beech, Schenley Park, 1 Dec 2020 (photo by Kate St. John)
Snow on Norway maple, Schenley Park, 1 Dec 2020 (photo by Kate St. John)
Eyebrow clouds, Moraine State Park, 4 Dec 2020 (photo by Kate St. John)
Moraine State Park, 4 Dec 2020 (photo by Kate St. John)
5 December 2020
Here’s a visual portrait of the past week, from a warm day at Duck Hollow on 29 November, to snow on 1 December, and yesterday’s awesome sky at Moraine State Park.
