European starlings (Sturnus vulgaris) are famous for their ability to fly in tight formation. When under attack by a peregrine falcon, they evade him in amazing ways.
Starlings under pressure fly closer together and shape-shift the flock like a giant blob in the sky. This makes it hard for the peregrine to choose a single bird as prey and gives their flocks a special name, a murmuration.
This winter Chad+Chris Saladin have been filming murmurations in Lorain, Ohio. Above on 30 December 2018, below on Christmas Day.
Last Saturday I tried to enjoy the Sunken Garden Trail at Moraine State Park but there were challenges along the way. The trail was very soggy, trees were down on the Short Loop, and part of the trail was under a few inches of water.
The flood is the work of beavers who backed up water in the wetlands (above) about 600 feet from the trail entrance (below).
The Sunken Garden Trail is truly sunken here. Fortunately ankle-high muck boots were more than enough to keep me dry.
Be prepared for mud in this winter’s warm weather. And watch out for black-legged ticks. I got one on my pants after I bushwhacked around downed trees. They’re moving around out there, though in slow motion.
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.
Why does this red-tailed hawk throw up a long gray lump? Is he sick? Not at all. He’s casting a pellet.
Birds’ digestive systems are very different from ours, beginning with their beaks. Since birds don’t have teeth they swallow most of their food whole. The rest of their digestive system is geared to deal with this.
Birds have little saliva and few taste buds compared with mammals, which chew and physically process food as the first step and then subject it to chemical processing as the second step. Birds reverse this sequence. They start chemical digestion in the proventriculus [then the food] undergoes physical processing in the gizzard.
Ornithology, 3rd Edition by Frank B. Gill, page 164
We chew with our teeth and spit out the bones. Birds chew with their gizzards which then collect the bones, fur, and other indigestible bits into a lump. The bird spits out the lump when it’s a convenient size.
Owls, eagles, hawks and falcons cast pellets but so do many other birds “including grebes, herons, cormorants, gulls, terns, kingfishers, crows, jays, dippers, shrikes, swallows, and most shorebirds.” (quote from Wikipedia)
Scientists examine pellets to find out what the bird ate. One of the long-eared owl pellets below was dissected to reveal the rodent bones inside.
For whatever reason, it’s rare to see a bird casting a pellet so consider yourself lucky if you witness it, as Chad+Chris Saladin did in the photos above.
A NOTE ABOUT HANDLING OWL PELLETS from Wikipedia: Some rodent viruses and bacteria can survive the owls’ digestive system so wear gloves and sterilize the pellets in a microwave oven before handling. A 2005 study found outbreaks of salmonellosis at elementary schools associated with dissection of owl pellets: Smith KE, Anderson F, Medus C, Leano F, Adams J, 2005. Vector-Borne and Zoonotic Diseases,5, 133–136.
(red-tailed hawk photos by Chad+Chris Saladin; pellet photo from Wikimedia Commons; click on the captions to see the originals)
Last week the news broke that NASA’s New Horizons spacecraft had flown by and photographed what looks like the “snowman of the universe,” two icy chunks stuck together like a snowman and spinning out there in the Kuiper Belt beyond Neptune.
Yes, this object spins. Here’s a time lapse from NASA on New Years Day 2019.
The snowman is reddish and tiny, only 20 miles long, so he can’t be seen from Earth. We wouldn’t even know about him except that a few years ago the New Horizons team looked for something interesting for the spacecraft to explore after it passed Pluto. They saw him as a dot using the Hubble Space Telescope in 2014 and chose him because he’s a classical Kuiper Belt object with low inclination and low eccentricity.
While looking for something else I found … this beautiful eye of stone. It’s so large that it’s best seen from outer space, as shown in a photo from the International Space Station.
The Eye of the Sahara or the Richat Structure is embedded in the Adrar Plateau near Ouadane, Mauritania. It’s 25 miles across — the distance from Pittsburgh to Greensburg — so people couldn’t see its unusual shape until we could fly above it.
Endogenic means “formed below the earth’s surface.” Indeed the Richat structure is a geologic dome, a magma bubble that hardened before it broke the surface then eroded away to expose the bubble’s onion-like layers. The youngest rock is on the outer edge, the oldest — 600 million years old — is in the center. The rust, blue, and white colors are the different kinds of rock.
This topographic reconstruction from satellite photos shows how the Eye is a bullseye bowl in the desert plateau.
In the end, it’s visible because it’s in the Sahara. No vegetation covers it and the wind has blown all the sand away.
(images from Wikimedia Commons and a video by Jeffrey Sonders; click on the captions to see the originals)