Connecticut warblers are rarely seen on migration and it's not just because they skulk in dense underbrush. A study published last May in Ecology shows they have a very unusual migration route.
McKinnon, Arturo and Love attached geolocators to 29 male Connecticut warblers in Manitoba in 2015, then recaptured four of them the following spring when they returned to breed. The data from the geolocators shows the four birds followed similar routes to their wintering grounds in South America.
After flying east to the Atlantic coast with stopovers along the way each bird launched out over the open ocean and flew two days non-stop to the Greater Antilles, probably Haiti. After refueling in the Caribbean they flew again over the ocean to South America and the Amazon basin.
In the spring we saw tents in the trees. Now we see webs. Though similar in concept, the structures aren't made by the same species.
The springtime tent, located in the crotch of a tree, is made by eastern tent caterpillars (Malacosoma americanum) who emerge from their tent to eat young leaves as they unfurl. The webs, located on the branches, are made by fallwebworms (Hyphantria cunea) who hide in the web and eat leaves that will fall off in a month or two.
Since late summer female moths have been laying egg masses on deciduous trees.
After a week the eggs hatch into tiny caterpillars who build a web to completely enclose themselves and their food. As they eat, they build the web larger to enclose more leaves.
Fall webworms avoid coming out of the web until they're ready to pupate. Then they hide their cocoons under flaps of bark to overwinter and emerge next year.
Though the webs look ugly they don't harm the trees because the leaves will drop soon anyway.
See webworms in action in the video above from The Capitol Naturalist in D.C. Read more in this vintage article from 2011: Coming Soon To A Tree Near You
(photo of fall webworm moth from Wikimedia Commons; click on the image to see the original)
As warblers migrate through Pennsylvania we find them feeding together in mixed flocks during the day. Does that mean they were traveling together overnight? Maybe not. Warblers often have very different breeding and wintering destinations, making it hard to coordinate their trips.
Here are two extreme examples. Blackpoll and pine warblers look similar but you can't find two more different migration strategies. Their breeding and wintering grounds are as far apart as it gets.
The blackpoll warbler, above, is a long distance champion who travels 7,000 miles from his breeding grounds in North America's boreal spruce and fir forests to wintering grounds in South America. To shorten the trip some of them fly non-stop over the Atlantic Ocean for 88 hours to reach South America's shore.
The pine warbler, below, never travels that far. His breeding and winter ranges are completely contained within North America from southern Canada to Florida and he's found year-round in the southern U.S. Pine warblers breed in parts of Pennsylvania.
The maps below -- blackpoll (left), pine warbler (right) -- tell the story in three colors: Yellow is breeding range, Blue is wintering range, Green is year-round.
As you can see, blackpolls leapfrog over the pine warbler's range.
Though I saw blackpoll and pine warblers in a mixed flock in Perry County last weekend, they probably weren't traveling together.
(photo of blackpoll warbler by Marcy Cunkelman; pine warbler by Anthony Bruno; maps from Wikimedia Commons: blackpoll and pine)
We'll visit Phipps Run and Panther Hollow Lake, looking for fall flowers and migrating birds. I'm sure we'll see goldenrod though I won't know what species it is. (Goldenrods are hard to identify!) Perhaps we'll see migrating monarch butterflies because the weather has been so warm.
Dress for the weather and wear comfortable walking shoes. Bring binoculars and field guides if you have them.
Before you come, visit the Events page in case there are changes or cancellations. The outing will be canceled if there’s lightning (unlikely this Sunday but you never know).
We saw the rainbow at dusk while the sun peeked below rain clouds and were surprised we could see the entire arc. Only those located at the geometric center of the rainbow, the antisolar point, can see it end to end.
Have you ever noticed that the sky under the rainbow is brighter than the sky outside it? True! Click here for an explanation (fourth paragraph).
And then there's the fancy stuff: the double rainbow and the extra bands under the arc. To illustrate them I'll use this photo from Alaska that shows all of the features at the same time. Click on the image to open a high definition version in a new window and see them up close.
Double rainbows happen when light bounces twice inside the raindrops before it exits. The light goes inside, reflects off the back wall, reflects off the front wall, and then exits. Double rainbows are parallel to the main rainbow, are not as bright, and their colors are reversed -- red-to-violet instead of violet-to-red. I never noticed that. I'll have to watch for it next time.
The marbled godwit (Limosa fedoa) breeds in northern prairies and at Hudson Bay, then migrates to the Atlantic, Pacific and Gulf coasts to spend the winter.
The bird is 16.5 to 19 inches long but that includes a 3-5 inch dark-tipped pink bill. The females are larger than males, big for a shorebird but small compared to a roseate spoonbill (click here to see).
The godwit's bill is a great tool for finding food. Its length allows him to probe deeply for small mollusks, bristle worms, insects, leeches (yes!) and sago pondweed tubers, and it's so sensitive that he can feel his prey without having to see it.
Click on the screenshot above to see Steve Gosser's video of a marbled godwit at Conneaut Harbor, Ohio early this month. Watch as she probes rapidly, then pulls up her beak to swallow a morsel. She plunges her bill so deeply that her face goes underwater.
This month chimney swifts (Chaetura pelagica) are migrating to South America, leaving before the weather's too cold for the flying insects they eat on the wing.
At dusk the flocks swirl around large chimneys then dive in to roost. This video from New Glasgow, Nova Scotia shows them streaming into an old schoolhouse chimney. Wow!
Don't worry when you see smoke coming out of the chimney at the end of the video. An observer explains: "There are actually two flues in the chimney. The chimney swifts use the larger flue, while the smoke is vented from the smaller flue, so the birds are safe. In fact, they probably benefit from the bit of heat that comes from the smaller flue."
Stake out a chimney in town to enjoy the air show or monitor a wooden chimney swift tower near you.
This year, for the first time since 1984, my husband and I aren't at Acadia National Park this month but I think of it every day. If I was there I'd be stopping by the base of this mountain to scan for peregrines. It's one of the few wild places where I know they nest.
On Throw Back Thursday here's a description of the peregrines' wild nest sites at Acadia with news from 2010:
There's another sign the ocean is warming. Fish are on the move. A wide variety of species including sole, haddock, herring, and black sea bass have left places too warm for them and migrated to cooler water.
For example an enormous Atlantic sailfish (Istiophorus albicans), normally off the coast of Florida above, was caught in the Cape Cod Canal in August 2013. It was the first Massachusetts record.
It's not just temperature that makes fish move. Warm water has less oxygen, so it's harder to breathe, and more carbon dioxide so it's more acidic. Acidic water holds less calcium carbonate, the building block of sea shells including those of tiny copepods. With fewer tiny organisms there's less food all the way up the food chain.
Fish swim away from these "deserts" but some animals can't move very far. Think of lobsters, now gone from Long Island Sound.