23 March 2013:
Here’s something you don’t see every day: two adult Coopers hawks perched near each other.
Coopers hawks are notoriously solitary birds. In winter we may see one hunting near our feeders, but never two. They don’t like others nearby. They chase them off or leave.
But now it’s breeding season and they have to find a mate.
Steve Valasek saw these two at Rio Rancho, New Mexico.
(photo by Steve Valasek)
Dorothy laid her fourth egg last night at 9:20pm (exact time on March 21 is thanks to the sharp eyes of Pittsburgh Falconuts).
Here, E2 is about to leave the nest after relieving Dorothy this morning. He’s looking up because she’s perched above him on the building. I saw her there from Forbes Avenue at the time.
And here’s Dorothy’s video from @PittPeregrines:
And today.. a quiz! See this link: Who are the falcons’ nearest relatives?
(photo from the National Aviary falconcam at the University of Pittsburgh)
22 March 2013
Remember the first time you were puzzled by the arrangement of birds in your field guide? Why were loons at the beginning of the book? Why did kingfishers come after hummingbirds?
It took me a long time to get used to taxonomic order but I finally mastered it and could thumb to the right place every time.
Not anymore! DNA testing has revealed new relationships. The old order is shaken up. Ostriches and ducks are first, kingfishers follow motmots, falcons have moved to be near their closest relatives.
So here’s a quiz:
Of the four birds shown below, which two are most closely related to peregrines?
Red-tailed hawk? Red-crowned parrot?
Red-legged seriema ? Yellow-crowned night heron?
Amazingly, parrots and seriemas are the falcons’ closest relatives. Seriemas, from South America, are actually an older species than falcons and peregrines. They are descendants of the terror birds (Phorusrhacidae).
The evidence first surfaced in 2006. In 2012, a proposal was made to the AOU (American Ornithological Union) to change the taxonomic order of falcons, moving them away from hawks and near parrots. Here’s a wealth of information on the move.
(photo credits: Peregrine falcon (Dorothy) by Jessica Cernic Freeman, Red-tailed hawk by Bobby Greene, Red-crowned parrot by Roger Moore Glandauer via Wikimedia Commons, Red-legged seriema from Wikimedia Commons, Yellow-crowned night-heron by Chuck Tague.
Inspiration for this Tenth Page comes from a conversation with Dr. Tony Bledsoe, Dept of Biological Sciences, University of Pittsburgh)
p.s. Click here for the new chart if the links above don’t work.
This year snow geese and tundra swans peaked in eastern Pennsylvania in mid to late February.
I missed their migration but Meredith Lombard visited Middle Creek Wildlife Management Area and captured a video of tundra swan interactions. (Clcik on the arrowhead to watch.)
These four swans are really hooting it up. The quartet began when two pairs encouraged their mates with lean-forward and wing-quiver calls. But the quivering wing display is also used in antagonistic encounters. When the males got too close the dominant male had had enough. He rushed the other one.
Whoa! The less aggressive male immediately sat on the water in a submissive posture and the situation defused. Watch him curl his neck down in an S position and look away.
Tundra swans can make music together. Sometimes they jazz it up.
(video by Meredith Lombard on Flickr)
Cars and trucks have changed the cliff swallow.
For 30 years Charles Brown and his wife Mary Bomberger Brown have studied cliff swallows (Petrochelidon pyrrhonota) in southwestern Nebraska. They’ve meticulously monitored, measured and banded the birds at their nests under bridges and overpasses and they’ve counted and measured the road killed birds.
Their attention to detail has paid off in an unexpected way.
Cliff swallows attach their mud nests to cliffs or bridges. In Nebraska where there are few cliffs, the swallows use busy highway overpasses. If the swallows aren’t quick to fly up out of traffic they become road kill.
When the Browns began their study in 1982 they typically found 20 road killed cliff swallows per season, but since 2008 they’ve usually found less than five. The traffic has remained the same while the swallows’ population has more than doubled, yet the road kill numbers dropped dramatically.
What changed? The swallows changed!
The Browns’ data reveals that thirty years ago Nebraska’s cliff swallows had longer wingspans. Today’s shorter wings allow the birds to maneuver more quickly and turn away from oncoming vehicles. In fact, the few road killed birds they find today have longer wings than the rest of the population.
The shorter-winged birds survive to breed, the long-winged birds do not. In only 30 years, traffic’s unnatural selection has forced cliff swallows to evolve.
If traffic can do this to cliff swallows, I wonder what it’s done to Pennsylvania’s white-tailed deer.
Read more about this study in ScienceNOW.
(photo of a cliff swallow near the Rt. 528 bridge in Moraine State Park by Chuck Tague)
Dorothy has definitely not completed her clutch.
Peregrine falcons begin incubation — they cover the eggs continuously — when the female has laid her next-to-last egg.
Today before dawn Dorothy roosted near her eggs but did not cover them.
Does she expect to lay five eggs this year?
Only time will tell.
(photo from the National Aviary falconcam at the University of Pitsburgh)
19 March 2013
As I mentioned a week ago, a pair of bald eagles took over a red-tailed hawks’ nest in Harmar Township early this month. Problem is, the hawks were still building the nest and they weren’t going to give it up easily.
Last week after continuous red-tail dive-bombing and harassment the eagles relinquished the nest to the hawks. There was a brief period of calm, then the eagles fought back.
On Sunday Steve Gosser captured their battle and posted it on Facebook’s Bald Eagles in Western Pennsylvania page. In a few hours his photo was shared more than 460 times.
Battle of the air! Clash of the Titans!
Who will win?
(photo by Steve Gosser)
Update in March 2020: The bald eagles won.
There are now three peregrine falcon eggs at the Cathedral of Learning nest.
Dorothy laid her third egg at about 2:00am today. (Click here for her latest video.)
Watch for her to begin “The Big Sit” (incubation) soon.
(photo from the National Aviary falconcam at the University of Pittsburgh)
p.s. Click here for my 2009 blog post that explains why I call it The Big Sit.
Here’s an unusual view of a female red-bellied woodpecker.
Normally we see her from the side and notice her black-and-white back and overall paleness. But from the top, and in bluish light, the gap in her red helmet almost makes her look bald.
Here’s her male counterpart. No doubt about his red head!
Watch for their mating ritual this month as they engage in “mutual tapping” on the tree they’ve chosen for their nest.
Thanks to Dan Dugan for this unusual look at a common bird.
(photos by Dan Dugan)
Pittsburgh’s Downtown peregrines are still busy courting.
Yesterday Louie paid a visit to Amanda McGuire’s Lawrence Hall balcony and attracted her attention because he whined so much.
Amanda held her cellphone out the screen door and captured a video of him. By the end of the video you’ll agree…
He’s a screamer!
(video by Amanda McGuire)
p.s. To make the video larger, click in the brackets at the bottom right of the YouTube TV screen. The red circle below shows you where.
