How does a pigeon avoid being lunch for a peregrine falcon?
He flies fast, he stays in a flock for protection, and he (quite literally!) keeps an eye out for danger.
Pigeons have such a wide field of view that they can see danger coming from almost any direction. There’s only a narrow place in front of them where both eyes focus and a narrow blind spot in the back. Pigeons are not alone. Many prey species have a wide field of view.
This is hard for us to imagine because our eyesight is like the raptor’s but raptors seem to know how it works. When a peregrine wants to sneak up on a pigeon he flies in the pigeon’s blind spot.
Even before the buds burst and the flowers bloom, birds give us a hint that spring is coming. Some of them turn yellow.
* White-throated sparrows have boring faces in the winter but their lores turn bright yellow ahead of the breeding season. They’ll leave in March or early April for their breeding grounds in the northern U.S. and Canada.
* American goldfinches were brownish all winter but molt into yellow feathers in late winter. Even the females turn a subdued yellow as seen in the female on the left in Marcy’s photo.
* At this time of year European starlings become glossy and their beaks turn yellow. The starling below is male because the base of his beak is blue (near his face).
There are other birds whose yellow facial skin becomes brighter in the spring. Can you think of who that might be? …
Yellow is a sign of spring.
(photos from Wikimedia Commons, Marcy Cunkelman and Chuck Tague. See credits in the captions)
Have you ever seen a distant white raptor and hoped it was a snowy owl or gyrfalcon? I have, but I’m usually wrong. Both species are rare and neither is here in spring or summer.
Snowy owls and gyrfalcons only visit Pennsylvania in late fall or winter. In most years snowies don’t come to the Pittsburgh area at all (this year is an exception) and gyrfalcons are never here. In over 100 years only 41 gyrfalcons were reported statewide (see *1 below).
And yet we still see an occasional rare white raptor, even in the summer. What hawk is this? In nearly every case it’s a leucistic red-tailed hawk.
“Leucism is a condition in which there is partial loss of pigmentation in an animal resulting in white, pale, or patchy coloration of the skin, hair, feathers, scales or cuticle, but not the eyes.” (quoted from Wikipedia). The condition is rare but red-tails are our most common hawk so it’s not surprising to find it in a numerous population.
The whiteness varies from hawk to hawk and even from year to year. Sometimes leucistic red-tails are spotted brown, sometimes they’re entirely white. Pat Gaines photographed a speckled one in Berthoud, Colorado this winter (above) and an all-white bird in North Denver in 2010 (below). Neither bird is albino because its eyes are the normal color, not pink.
Even the all-white birds have at least one normally-colored feather. It’s a tail feather on this hawk, as shown in Pat’s photo below.
(*1) How rare are gyrfalcons in PA? In 1982 and 1984, DVOC’s Cassinia analyzed all the reports of gyrfalcons in Pennsylvania. From the mid 1870’s to 1984 only 41 were confirmed: Gyrfalcon Records in Pennsylvania, Part One, 1982 and Gyrfalcon Records in Pennsylvania, Part Two, 1984. Most reports were in Schuykill, Carbon, Berks, Lehigh and Lancaster counties with only 2 reports at Presque Isle, Erie County (there have been more since then). As of 1984, the most recent sighting of a gyrfalcon in Pittsburgh’s 11-county metro area was 1 bird in Westmoreland County in January 1913.
(photo credits: evening grosbeaks at the Smithsonian by ap2il via Flickr, Creative Commons license. Northern cardinal courtesy of Western Illinois University. Click on the captions to see the originals.)
The two wild turkeys at top are displaying to females. Which one has the best snood? I can’t tell but the females can. Click here to see how the ladies reacted.
(photo credits: two wild turkeys by Cris Hamilton; women wearing snoods from Wikimedia Commons; man wearing a beard snood from sales page at Creeds UK; wild turkey diagram from Wikimedia Commons. click on the images to see the originals)
Thirty years ago Japanese trains had a problem. They could travel fast but they caused sonic booms.
The answer was the bullet train. How did Japanese engineers develop it? They learned from birds.
Watch this 6+ minute video from Vox + 99% Invisible to learn how birds showed the way and follow one woman’s quest to teach engineers that Nature has the answers. Our world can benefit from biomimicry.
For best results, copy birds.
Thank you to Holly Hickling for sharing this. For more cool videos, follow Vox (news site) or 99% Invisible (city design updates) on Facebook.
After most warblers have left for the winter, the yellow-rumped warblers come back to town.
Breeding across Canada and the northern U.S., yellow-rumped warblers (Setophaga coronata) spend the winter in North America as close to us as Ohio and eastern Pennsylvania, though not usually in our area. In late fall they stop by in Pittsburgh.
Yellow-rumps don’t have to leave for Central or South America because they have a unique talent. Their bodies can digest wax. In winter they eat the waxy fruits of bayberry and juniper. Since bayberry is also called wax myrtle, it gave our common subspecies its name: the myrtle warbler.
On Throw Back Thursday, learn how yellow-rumped warblers get nutrition from wax in this vintage article: Anatomy: Wax Eaters.
p.s. Notice that the warbler in the Wax Eaters article is wearing bright breeding plumage in black, white and yellow . Autumn yellow-rumps are dull brown with a faint vest and a broken white eye ring. The best clue to their identity is their yellow rump.
In 2014, genome sequencing studies led by Robert W. Meredith worked to determine whether several branches of birds’ ancestry lost their teeth independently (convergent evolution) or whether all birds have a common ancestor that evolved a toothless beak.
The project did full genome sequencing on 48 birds species representing nearly all modern bird orders. They then focused their study on six genes related to tooth enamel. All six genes became non-functional in a common bird ancestor around 116 million years ago. That’s when birds lost their teeth.
(cropped image of Archaeopteryx model on display at Geneva natural history museum via Wikimedia Commons; click on the image to see the original. **Note that this Archaeopteryx model has accurate teeth but has other inaccurate/disputed features as described on Wikimedia Commons: “Archaeopteryx had a more round shape of its wings, the primary feathers were attached to the second finger unlike here, and these colours are now known to be wrong.”)