Last year around this time I saw quite an example of feather molting!
I was sitting outdoors just after dawn when I heard a cardinal make warning calls behind me. I couldn't see her but I could tell she was upset by my presence, though I didn't move. Eventually she popped out and perched on a branch in full view.
Yikes! She was ugly! All the feathers were missing from her head and face except for one tuft where her crest should have been. Her skin was black. I could see her ear holes.
I don't have a picture of her but if I did you wouldn't want to see it. Way too ugly!
Common green darner dragonflies (Anax junius) are fast and powerful fliers, the highly maneuverable "fighter jets" of the bug world.
Like peregrines they capture their prey on the wing but their methods are those of flycatchers. They chase flying insects and grab them with their mouths.
Though some common green darners overwinter as nymphs, many of them migrate at this time of year. The adults fly south pretty rapidly but those who fly north in the spring take their time to reproduce so that the individuals then are a later generation than the ones who left.
How fast and far do these bugs travel?
In 2005 a team of scientists attached very tiny radio transmitters to 14 common green darners in New Jersey and followed them on the ground and in the air using radio receivers and a Cessna airplane.
The results were intriguing. These dragonflies make many of the same migration choices as songbirds. They...
Avoid large bodies of water and will head north to go around them. Dragonflies that reached the tip of Cape May traveled up the shore of Delaware Bay to find a narrower crossing.
Rest on windy days (of course!). They prefer winds less than 15 mph.
Prefer to fly on the day after two nights of successively lower temperatures. This is usually a day with a north wind.
Can fly for 8 hours on stored fat.
Migrate every three days on average, so their daily progress comes to 7.5 miles/day with idle days included.
On a good day they can travel 60 miles.
Their average speed is 5 meters/second = 11.18 mph.
In two months they've traveled 700k (435 miles).
So when you see a green darner, view it with awe. It's one of only a dozen dragonflies -- out of 400 species in North America -- who migrate.
p.s. The bug in this photo is male; he has a blue abdomen.
Fall is coming, school's in session and in about eight weeks the crows will be back in town.
For now they're in no rush to get to Pittsburgh. I don't expect large numbers until October, but when they come will I see a difference in them? Did they learn new tricks this summer? Will they be even smarter than last year?
Perhaps they've learned to use tools!
Here's a year-old video from Science Friday that shows just how smart crows can be. (Click on the image to get to the video website from September 2010.) The birds in the film are New Caledonian crows who live on a Pacific island and are famous for using tools.
It looks like this happened fast but in fact it takes about two hours for the adult to emerge and dry off. During that time its body is soft, like a softshell crab, and it's quite vulnerable to predation.
When the adult's wings and body have hardened, the adult flies away leaving his old skin behind, including his legs and the covers of his eyes.
No need to be afraid of this bug. He's just a shell of his former self.
This hawkwatch site "holds the highest season total for Peregrine Falcon migration, with 2,858 birds observed during the 2003 season, and is the world’s highest daily Peregrine count, with 638 birds counted on October 11, 2008!"
Think of it: 638 peregrines in one day!
That was exceptional, but normal high-counts at FKH are about 100 peregrines per day. Here are the peregrine counts from October 2010. Instead of the date, I've typed the number of peregrines counted that day.
FKH October 2010 Peregrines
Florida Keys Hawkwatch welcomes volunteers of all skill levels. They'll provide training and housing (see their guidelines) or can direct you to local lodging and resorts.
If you'll thinking of a fall vacation this is the perfect place for beaches, boating, fishing and peregrines!
Click here for information on Florida Keys Hawkwatch. Click here to volunteer and find out about housing/lodging.
Florida Keys Hawkwatch in October! 100 peregrines a day!
I felt the earth move under my feet ... and you may have too!
Earthquakes are very unusual in Pittsburgh but just before 2:00pm, while Karen Lang and I were sitting on a cement bench near Heinz Chapel, I felt the bench swaying back and forth as if we were on a swing. I asked Karen, "Do you feel that?"
Yes, she did. "I think we're having an earthquake!"
In Smithfield, Virginia my sister was sitting on her sofa, 120 miles from the 5.8 earthquake epicenter in Mineral, Virginia, when the whole house started to shake and sway. It started at ground level and worked its way up the house's three stories -- almost like a dog shaking off water from head to tail. Mary was transfixed. The worst swaying was on the third floor where my niece shouted, "Mom! The glass is going to fall off the shelves!"
Fortunately the quake didn't last long. Nothing fell. Nothing was damaged.
We're all a little surprised. Just a little excitement in nature today.
(Seismogram image from Wikimedia Commons. Click on the image to see the original.)
Yesterday 37 bird blog and peregrine fans gathered at the National Aviary to see the sights, learn about birds and watch the Sky Deck show. We had fun!
Steve Sarro, Director of Animal Programs, gave us a wonderful tour and taught us a lot about birds.
The favorite thing I learned is this: Steve told us that African penguins add 50% to their weight just before they molt and then they lose all their feathers at once! It takes several weeks to grow them back. One of the Aviary's African penguins, Elvis, is molting right now and he sure looks shaggy. He's in a good mood but he's having a couple of "bad hair weeks."
Up at Sky Deck, the weather was perfect for flying and the birds were awesome. Amut, the lanner falcon, flew for the lure and used amazing "sneak attacks" by flying below the building's edge, then popping up over Sky Deck to hit it. Heather Jacoby got a nice photo of her on the glove, above. Here is Sharon's video:
Much as we love falcons, everyone agreed that the black kites were the best. All six of them flew above us snatching food out of the air. At one point three of them went for the same airborne morsel and gracefully avoided a midair collision. Click on Heather's photo of the black kite (below) to see Sharon's video of them flying.
We had a great time on our afternoon full of birds as you can see by our smiling faces. Thanks to all of you for coming! And thanks to Heather and Sharon for sending links to their photos. If you have photos you'd like to share, leave a comment with your links below.
p.s. The Aviary is open all year, but Sky Deck is just a summertime show so visit now while the weather is perfect for flying. For more information see the National Aviary website at www.aviary.org
(Lanner falcon and black kite photos by Heather Jacoby. Group photo by Sharon Leadbitter.)