This week’s weather was like a yo-yo — summer last weekend, winter mid-week, spring today. The cold was annoying to us but potentially fatal to purple martins who migrated from Brazil and arrived in western Pennsylvania 2-3 weeks ago.
Purple martins feed exclusively on flying insects but when temperatures stay below 50F or it’s extremely windy, constantly raining, or dense fog, insects don’t fly. After more than two days of this, purple martins weaken and starve.
Members of the Purple Martin Conservation Association remember the awful purple martin die-off when Hurricane Agnes lingered over western Pennsylvania in August 1972. It took more than 30 years for purple martins to come back to our area.
In the past purple martin landlords felt helpless as they watched their colonies weaken and die. In the 1990′s Ed Donath trained his martins to eat non-traditional food but that required training time during good weather. Then during a cold spell in April 2000 Ken Kostka and Andy Troyer figured out an emergency feeding strategy: toss live crickets in the air. At first the purple martins idly watched the airborne objects. Then they recognized the crickets as insects and made the connection “flying+insects”=food. The martins feasted and the colony was saved.
The home video above by Larry Melcher shows how it’s done. After the martins have learned to recognize the crickets as food, the bugs can be placed on a high tray on the colony and the martins will eat them even though they’re not flying.
Landlords have experimented with other foods. Years ago Bird Man Mel in Missouri tossed live mealworms so his colony now recognizes mealworms as food and will eat them from the front porch trays (click here for his video).
On Wednesday birders Dick Nugent and Debbie Kalbfleisch visited a purple martin colony in Butler County where the landlord was feeding his colony scrambled eggs! Here’s a video with the scrambled egg recipe.
Purple martin landlords love their birds. They start feeding crickets, then let them eat eggs.
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.
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.
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.
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.
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.)
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.
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.