A few days ago I looked out my office window and saw two American robins perched on the dumpsters at Central Catholic High School. As I watched, one dove into a dumpster and disappeared. Soon it flew out of the flap opening on the left and the other robin dove in.
What is this? I’m used to seeing crows, gulls and even house sparrows at dumpsters … but robins??
I tried to photograph the robins but always missed so I’ve had to settle for a snapshot of the dumpsters with a green symbol for the robins’ favorite pre-dive perch.
I wonder what attracted them into the dumpster.
I did not dive in to find out!
(photo by Kate St. John)
This month the starling flocks will break up when the visitors head north and the locals begin to nest. In the meantime this informational tidbit may be useful in controlling their roosting habits … or it might not.
On a random search about starlings I found this statement on Wild Birds Unlimited’s Chipper Woods website: “Starlings have a well developed sense of taste, and are repelled by grape flavoring. Fogging with grape flavoring is an effective and environmentally safe method to discourage these birds from roosting.”
I know that starlings will eat just about anything, including grapes, so I wonder: What is grape flavoring made of? Do starlings detect something unnatural and dangerous in it that we cannot?
This starling, photographed in Toulouse, France, knows the answer. You can tell by his look that he has a well developed sense of taste.
(photo from Wikimedia Commons, Creative Commons license. Click on the image to see the original.)
We think of eastern bluebirds as gentle birds. They seem to be poor fighters and often lose battles with house sparrows and starlings, so I was surprised to learn from Karen DeSantis that she witnessed two male eastern bluebirds in a long ferocious fight in late February a few years ago.
Karen described on PABIRDS how the fight began with chasing, then escalated into periodic knock downs and grim combat on the ground. The males fluttered and rolled over a distance of about 30 feet while the female followed every move, twittering as she watched. The birds were so oblivious that Karen was able to take photographs of the 15-minute battle. Karen wrote, “It was the long duration of the fight that interested me the most.”
Though we might not realize it, these battles are consistent with bluebird behavior.
During the winter bluebirds flock in family groups and huddle together to stay warm. In early spring their togetherness ends as the fathers eject their sons from the group before ‘Mom’ and ‘Dad’ nest again.
But the battle Karen witnessed was not a mild family squabble. Its intensity indicates the guys were fighting over the lady.
Bluebirds are usually monogamous but about 20% of the young come from extra-pair copulations. The males seem to know if their ladies’ eyes are wandering and guard their mates more closely if they’ve been messing around. According to Birds of North America Online, “Experimental evaluations (Gowaty 1980) indicate male-male aggression most likely serves to protect threatened paternity. Males are aggressive to males usually in defense of paternity.” These battles can be so intense that they end in the crippling or death of one of the birds.
Bluebirds may seem gentle but don’t mess with their mates! Click on Karen’s photo above to watch a slideshow of the fight.
(photos by Karen DeSantis)
Last fall Parrot Confidential introduced us to the ARA scarlet macaw recovery project in Costa Rica and a bird named Geoffrey who was abandoned by his mother. I assumed at the time that Geoffrey was rescued because his mother was new to motherhood and unskilled in raising her first brood.
But no. Scarlet macaws have a very unusual parenting strategy. The female lays up to four eggs but when the eggs hatch the parents choose just one of the nestlings — usually the first — and shower it with attention. The rest are ignored, unfed, not brooded. They die within three weeks. The parents raise an only child.
I learned about this very unusual behavior in an article in wired.com about the Tambopata Macaw Project in southeastern Peru. Since 1989 the project has collected a wealth of information on scarlet macaw biology and behavior including the birds’ habit of raising only one chick each year. From Nadia Drake’s article:
Observations suggest that this outcome is one of choice, rather than resource limitation. So far, the reasons why are still a mystery. This parenting strategy seems to be unusual even among birds, which often lay extra eggs and then distribute limited resources among chicks with brutal efficiency.
The truth is that macaw chick mortality does not appear to be the accidental or inevitable result of scarce resources.
“This is death by neglect,” said ornithologist Donald Brightsmith of Texas A&M University. “Complete and utter neglect.”
This parenting strategy is an unfortunate trait for an endangered bird but it explains why the ARA Project has a natural supply of baby scarlet macaws: Every nest has an abandoned nestling. By raising the “extra” birds the project boosts the local population.
Scarlet macaws are very intelligent. They have a reason for choosing to raise an only child. We just don’t know what it is yet.
Read more here at wired.com.
(photo in the public domain from Wikimedia Commons. Click on the image to see the original)
Birds are often on camera, but rarely on the camera.
This photo of a pygmy nuthatch was an experiment by Ed Sweeney (Navicore on Flickr). Thanks to its Creative Commons license on Wikimedia Commons, I found the photo and learned of Ed Sweeney’s extraordinary photographs. See more on his Flickr page here.
(photo by Ed Sweeney, on Wikimedia Commons. Click on the image to see the original and Creative Commons license.)
Unseasonably cold weather continues in Pittsburgh though we’ll have a “heat wave” of 26oF today while it’s snowing 2-4 inches. Then the temperature will dip to -7oF by Monday night. Erf!
When Steve Gosser posted this white-throated sparrow on Facebook, many remarked that the bird is fluffed up and frowning! It looks like he’s tired of winter.
“This is getting old.”
(photo by Steve Gosser)
If birds left a visual trail in the sky, what would their flight paths look like?
Dennis Hlynsky, an artist and professor at the Rhode Island School of Design, has been experimenting with this for several years. He became interested in birds when “During the winter of 2008 I left the house in the wee early morning looking for anything to record with my new pocket video camera. I began to notice life above.” Since then he’s been filming birds and animals, then using Adobe After Effects to convert their motion to dotted trails. Fast-moving birds become open dashes, slow-moving ones are thick lines.
Starling videos are especially interesting because the flocks collect a few birds at a time and flee in a tightly packed blob. Click on the screenshot above to watch Hlynsky’s video “data in data out” of starlings on wires in East Providence.
Thanks to Traci Darin for pointing out this video in an article on the Colossal website where you can see an animation and three additional flight path videos. Or click here for Dennis Hlynsky’s “small brains on mass” website where he’s posted videos of birds, water striders and the carp feeding at Linesville, PA.
(screenshot from Dennis Hlynsky’s video “data in data out” on Vimeo)
House sparrows are always gregarious, but more so in winter when they flock together in large numbers.
In the morning and afternoon they disperse to feed, but twice a day — at midday and in the evening — they gather in dense shrubs or evergreens and chatter for an hour or more. They sound a lot like this.(*)
You might not hear them in today’s cold weather but when you do it’s unmistakable. They’re in a bush alive with birds … but you can’t see them. I’ve tried to count them but they fall silent and hide when I approach. I rarely see even one.
Here’s a flock in a tree, somewhat hidden but easier to see than inside a privet hedge!
House sparrows love each others’ company so much that, according to the Stokes Guide to Bird Behavior, some travel up to four miles to join the roost.
“Gregarious” works for house sparrows — from Latin gregarius (from grex, greg- ‘a flock’) + -ous (to make it an adjective).
(photos from Wikimedia Commons. Click on the images to see the originals)
(*) The sounds at the link above are similar but not quite the same as winter chatter because they’re from a more intense breeding chase in April. Listen to this segment from BirdNote for all the sounds house sparrows make.
In this week’s very cold weather it’s hard to stay warm but birds have a few strategies that help.
They eat a lot and they also naturally shiver to stay warm. Shivering sounds pathetic but it actually works because the muscles generate heat. The big pectoral (breast) muscles are the best for this.
Some birds shelter in nooks or crannies of hollow trees or on the outsides of our buildings. Look at chimney tops and you’ll see starlings absorbing the warm exhaust. On Monday I saw a peregrine at Pitt facing inward at a high window on the Cathedral of Learning. The window was warmer than the surrounding air.
Other birds come indoors. On Monday afternoon Richard Nugent reported he’d found a Carolina wren sheltering in his heated garage as the temperature was heading for -12 degrees that night. What a smart wren! Richard put out food and water for the bird to enjoy while it waited for the weather to improve.
Huddling helps. Inca doves not only huddle sideways as shown above but they make pyramids two or three rows high. According to Ornithology, as many as 12 Inca doves will form a pyramid, fluff their feathers and face downwind in a sheltered sunny place. “In large pyramids, doves exposed on outside positions try for better positions in the top row and cause the whole pyramid to readjust.” This sounds like a circus act, amazing to watch.
Last night was the last of the bitter cold. If the birds can make it through today the weather will moderate, then switch to above-normal temperatures this weekend.
Hang in there, little birds. Help is coming soon!
(photo by Penny Meyer via Flickr, Creative Commons license. Today’s Tenth Page is inspired by page 158 of Ornithology by Frank B. Gill.)