Posts tagged birds

Posts tagged birds
Transgendered bellbird found in New Zealand
Biologists at the Zealandia eco-sanctuary in New Zealand have spotted a bellbird that exhibits features and behaviour of both male and female members of the species.
The bird hatched in early 2011, and DNA testing then showed it as female, but since then its development has been rather different to normal female korimakos.
Normally, female bellbirds have a white feather pattern but the chick bean to show signs of the dark plumage normally seen on male birds. It also began to behave in a masculine way, not flitting between flowers like a female bellbird but instead moving with purpose, ready to defend its territory.
The bird’s calls are unusual too. It makes both male calls and the distinctive “chup chup” normally heard from females, but the latter are louder and more frequent that is normal.
Zealandia conservation officer Erin Jeneway told the Dominion Post: “There’s something we can’t pin down. We haven’t seen anything like this before”. Victoria University biologist Ben Bell added: “It could be due to a hormonal imbalance or it could be a reaction to shock or an incomplete moult — given the appearance and behaviour, any of those would be unusual though.”
Finches flirt unwisely if they can only use their left eyesA patch over a male Gouldian finch’s right eye works like beer goggles, though the bird doesn’t need booze to flirt unwisely. If limited to using his left eye when checking out possible mates, he risks making really stupid choices.
Gouldian finches have caps of black, red or yellow feathers on their heads. In nature, the birds prefer to mate with partners with the same cap color. Yet black-headed males rendered temporarily left-eyed by a tiny removable eye patch flirted as readily with red-heads as with black-heads, says cognitive ecologist Jennifer Templeton of Knox College in Galesburg, Ill. That’s not smart because daughters typically fail to survive when Gouldian finches mate outside their cap color.
Also the male himself “becomes less attractive,” Templeton says. When the bird’s right eye was covered, he sang, bowed and posed less during his attempts at courtship. Some left-eyed males didn’t manage to make up their minds at all, but “just hopped around randomly,” Templeton says.
[Full article] In the eye of the beholder: visual mate choice lateralization in a polymorphic songbird
By studying how birds master songs used in courtship, scientists at Duke University have found that regions of the brain involved in planning and controlling complex vocal sequences may also be necessary for memorizing sounds that serve as models for vocal imitation.
In a paper appearing in the September 2012 issue of the journal Nature Neuroscience, researchers at Duke and Harvard universities observed the imitative vocal learning habits of male zebra finches to pinpoint which circuits in the birds’ brains are necessary for learning their songs.
Knowing which brain circuits are involved in learning by imitation could have broader implications for diagnosing and treating human developmental disorders, the researchers said. The finding shows that the same circuitry used for vocal control also participates in auditory learning, raising the possibility that vocal circuits in our own brain also help encode auditory experience important to speech and language learning.
Cross a crow and it’ll remember you for years. Crows and humans share the ability to recognize faces and associate them with negative, as well as positive, feelings. The way the brain activates during that process is something the two species also appear to share, according to new research being published this week.
"The regions of the crow brain that work together are not unlike those that work together in mammals, including humans," said John Marzluff, University of Washington professor of environmental and forest sciences. "These regions were suspected to work in birds but not documented until now.
"For example it appears that birds have a region of their brain that is analogous to the amygdala of mammals," he said. "The amygdala is the region of the vertebrate brain where negative associations are stored as memories. Previous work primarily concerned its function in mammals while our work shows that a similar system is at work in birds. Our approach could be used in other animals – such as lizards and frogs – to see if the process is similar in those vertebrates as well."
Marzluff is the lead author of a paper being published the week of Sept. 10 in the online edition of the Proceedings of the National Academy of Sciences.
Baby songbirds learn to sing by imitation, just as human babies do. So researchers at Harvard and Utrecht University, in the Netherlands, have been studying the brains of zebra finches—red-beaked, white-breasted songbirds—for clues to how young birds and human infants learn vocalization on a neuronal level.
While a baby bird mimicking the chirps of his “tutor” may seem far removed from human learning, the researchers at the two universities found that the songs of the birds and human language are both processed in similar areas on the left sides of the two very different brains. The discovery was published last month in the Proceedings of the National Academy of Sciences.
Early fruits of the collaboration between the Genome 10K project and Beijing Genomics Institute (BGI) to sequence 100 vertebrate species have resulted in the sequencing and release of the genome of one of naturalist Charles Darwin’s Galápagos finches, the medium ground finch Geospiza fortis.
This finch genome, the first of the BGI-Genome 10K collaboration to be made available through the UCSC Genome Browser, represents both a scientific and a symbolic advancement, according to Erich Jarvis, Duke University associate professor who studies the neurobiology of vocal learning in songbirds.
Endemic to the subtropical or tropical dry forests and shrublands of the Galápagos Islands this species evolves rapidly in response to environmental changes. ”These finches are of great historical significance, but when Darwin first studied these birds, he was unlikely to have envisioned how this species would become a perfect model to study evolution in action,” said Goujie Zhang, BGI’s associate director of research. “Having the reference genome of this species has opened the door for carrying out studies that can look at real-time evolutionary changes on a genomic level of all of these enigmatic species.”
(Image by: Petr Baum)