Showing posts with label crows. Show all posts
Showing posts with label crows. Show all posts

12 October 2013

Ways to deal with Bully Birds



Bully birds include Crows, Blackbirds, Pigeons, Starlings, Mynahs and House Sparrows. These hungry avians are often attracted to a yard by cheap wild birdseed mix or suet that's made available on the ground or in easy-access feeders. 

Bully birds are a nuisance, but you can take some simple steps to prevent the larger birds from dominating feeders—thus allowing less aggressive birds to get close and feed. Here’s how: 


1. Modern Feeders: As bully birds are generally larger than most of the more “desirable” feeder birds, look for a rubber-coated mesh that surrounds traditional tube, suet and tray feeders. It allows smaller birds to pass through and enter the feeding chamber. Bullies such as Blackbirds, Pigeons, Crows and Mynahs can’t squeeze through. 


The photographs in this posting are of different styles of Bird Feeders readily available, if not at local shops here at Tiruvannamalai, then easily ordered and purchased online.


Squirrel proof baffler


2. Take cover: Many bully birds are known for their love of suet cakes, and it is not unusual for them to eat a whole cake in a single day. To prevent them taking advantage, hang suet feeder under a domed squirrel baffle or buy a Starling-proof suet feeder, which allows birds access to food only from beneath the feeder. Starlings are reluctant to go under any sort of cover. 



Impossible for larger birds to perch at


3. Catch seeds: Many find that foiling bullies at feeders isn’t quite enough because they often eat the food that the other birds drop on the ground. To solve this problem, place a large container under a hanging feeder. Bully birds are unlikely to fly into the container to get discarded seed. 


Keeps all the Crows and Blackbirds at bay

4. Be selective: Selective feeding is another way to control the kinds of birds that eat at your feeders. Generally, bully birds prefer bread, corn millet, wheat and sunflower seeds and do not like safflower or nyjer (thistle) seeds. By offering just selective seeds—and not wild bird seed mixes—only smaller less aggressive birds will come to the feeders to eat. 

If you feel tube feeders with with only nyjer seed (thistle) and safflower seeds in hopper or tray feeders, such birds as Crows and Blackbirds will generally look elsewhere for the foods they like. 



Suet Cake Feeder


Another type of suet feeder uninviting to large bully birds


5. Aid acrobats: Bully species usually require a perch to hold onto while eating, but most finches and many other small feeder birds can eat without perching at food ports. Finches can cling to the sides of a tube feeder and eat all day long. Bullies can’t. Some commercial tube feeders have perches above the food ports, where the birds have to stretch downward to feed—something that bully birds can’t do either. 


Nice Baffler bird feeder

6. Use bottles: Thwart suet-eating bullies at a cage like feeder by inserting a long perch that extends out both sides, placing a small soda bottle over each end. When a bully lands on a soda bottle, the weighty visitor rolls off the perch. Smaller birds are too light to roll off the bottles while feeding, or they can cling to the wire cage.

7. Offer alternatives: A male hummingbird is often aggressive and protective of a sugar-water feeder that he considers his own. Only “his females” and their young are allowed to feed undisturbed. The simple solution is to set up an additional sugar-water feeder on another side of your house, out of sight of the other male’s domain. 


Happy, thriving birds at feeder


8. Buy weights: Look for a bird feeder that has a weighted perch or treadle. When larger, heavier birds land on a treadle, it drops down over the bird food. (This device works against squirrels, too.) Lightweight birds can reach the food because the treadle does not drop down when they perch. 



When this big, NOTHING is going to keep you out!



Easy ways to discourage bullying birds and to make a haven for small indigenous birds: 

Keep less open, grassed areas in your garden. This type of open environment tends to encourage the bigger birds. For smaller birds, set aside at least a part of your garden and allow them some territory of their own. 

Create a garden with dense plants. The creation of denser foliage and the reduction of grassed areas will create a safe haven for smaller birds. Grow thickets as they are ideal hiding places and homes for smaller birds. Experiment with thick rows of shrubs rather than just having one or two here and there. 



11 January 2013

Very Clever Crows



A recent posting in Science Now, the daily online news service of the journal Science explored the question of whether Crows are mind-readers. We all know just how smart and naughty crows are and how they are very successful in usurping other bird and taking over their territories – but the below narrative suggests that crows have a complex intuition that has been seen in only a select few creatures – that of hiding food to protect it from theft. 



Crows Really Are Mind-Readers 



Scrub Jay takes a test


Are crows mind readers? Recent studies have suggested that the birds hide food because they think others will steal it — a complex intuition that has been seen in only a select few creatures. Some critics have suggested that the birds might simply be stressed out, but new research reveals that crows may be gifted after all. 

Cracks first began forming in the crow mind-reading hypothesis last year. One member of a research team from the University of Groningen in the Netherlands spent 7 months in bird cognition expert Nicola Clayton’s University of Cambridge lab in the United Kingdom studying Western scrub jays, a member of the crow family that is often used for these studies. The Groningen team then developed a computer model in which “virtual jays” cached food under various conditions

In PLOS ONE, they argued that the model showed the jays’ might be moving their food—or recaching it—not because they were reading the minds of their competitors, but simply because of the stress of having another bird present (especially a more dominant one) and of losing food to thieves. The result contradicted previous work by Clayton’s group suggesting that crows might have a human like awareness of other creatures’ mental states—a cognitive ability known as theory of mind that has been claimed in dogs, chimps, and even rats. 

In the new study, Clayton and her Cambridge graduate student James Thom decided to test the stress hypothesis. First, they replicated earlier work on scrub jays by letting the birds hide peanuts in trays of ground corn cobs—either unobserved or with another bird watching—and later giving them a chance to rebury them. As in previous studies, the jays recached a much higher proportion of the peanuts if another bird could see them: nearly twice as much as in private, the team reports online today in PLOS ONE. 

Then came the stress test. First, Thom and Clayton gave the jays trays with the ground cobs but no food to hide in them—a so-called “sham” session. Then, in a second session, they gave the birds new hiding trays and bowls of peanuts to hide. When the jays were done, the experimenters removed the trays and stole all of the peanuts. Finally, after a short break, the researchers gave each bird yet another round of food, a new tray to hide it in, and one of the trays it had seen earlier: either the sham tray or the ransacked “pilfer” tray. The jays had 10 minutes for recaching. 

If the Groningen model was correct, Thom and Clayton argue, the stress of discovering that food was missing from the pilfer tray ought to drive jays to cache more peanuts than those presented with the sham tray. In fact, there was no difference, even though corvids have excellent memories for hidden food and remarkable abilities to find it again. The hypothesis that jays have theory of mind remains on the table, Thom says. 

Thom and Clayton have “definitely shown that scrub recaching is not as simple as the [Groningen] model presents it,” says Elske van der Vaart, lead author of the Groningen team’s earlier report, who is now at the University of Amsterdam. But she argues that there is still room for doubt about what the results mean. For example, the sham condition—in which the jays had no food to cache—could have stressed the birds as much as the stolen peanuts in the pilfer condition did. 

Amanda Seed, an animal cognition researcher at the University of St. Andrews in the United Kingdom, says the Groningen model’s failure to predict the birds’ caching behavior in the new experiments could “bring the model down like a pack of cards.” But researchers still have to rule out other possible explanations, she says. For example, the birds given pilfered tray may have noticed the missing peanuts too late to affect their overall caching rate, or they may have spent much of their time looking for the missing nuts instead of hiding the new ones. The Cambridge and Groningen groups are planning more work with both real and “virtual” birds to see what is really going on. “I applaud them for rising to the challenge,” Seed says.