Birds of southeast Texas in photos

Birds on their first migration rely on the magnetic field and the sun, in future migrations the smells along the route help to guide them.

Adult migratory birds are clearly able to remember migration routes. Even if they end up flying over unknown terrain, they still manage to find their way to the right place. Researchers at the Max Planck Institute for Ornithology in Radolfzell and their colleagues at the universities of Princeton, Pisa and Copenhagen have established in a field study that odours considerably facilitate bird migration and act as a more important navigational cue than the sun and the earth’s magnetic field. ( read more Birds follow their noses during migration )

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Abstract and paper $
Natural ‘Magnetometer’ in upper beak of birds?

Oxford released a video this week of wild crows using tools.

A new study using motion sensitive video cameras has revealed how New Caledonian crows use tools in the wild.

Previous work has shown the sophisticated ways in which crows can use tools in the laboratory but now a team of scientists from Oxford University and the University of Birmingham have investigated tool use in its full ecological context. The researchers recorded almost 1,800 hours of video footage for the study and publish their findings in Proceedings of the Royal Society B.

In the wild, New Caledonian crows use tools for many purposes, including ‘fishing out’ large beetle larvae from holes in dead wood. In the new study the team were able to show for the first time that more larvae were extracted by crows using tools than with their beaks.

They also discovered that adult crows appeared to be much more skilled at obtaining larvae than juvenile crows, suggesting that considerable learning – possibly from copying more experienced ‘larvae fishers’ – is required for crows to become competent at this task. . . .read more

Paper:
Tool use by wild New Caledonian crows Corvus moneduloides at natural foraging sites

The Great Backyard Bird Count

New York, NY and Ithaca, NY—Bird watchers coast to coast are invited to take part in the 13th annual Great Backyard Bird Count, Friday, February 12, through Monday, February 15, 2010. Participants in the free event will join tens of thousands of volunteers of all levels of birding experience to count birds in their own backyards, local parks or wildlife refuges.

Each checklist submitted by these “citizen scientists” helps researchers at the Cornell Lab of Ornithology and the National Audubon Society learn more about how the birds are doing—and how to protect them. Last year, participants turned in more than 93,600 checklists online, creating the continent’s largest instantaneous snapshot of bird populations ever recorded.

“Taking part in the Great Backyard Bird Count is a great way to get outside with family and friends, have fun, and help birds—all at the same time. Anyone who can identify even a few species can provide important information that enables scientists to learn more about how the environment is changing and how that affects our conservation priorities,” said Audubon Education Vice President, Judy Braus. “Everyone who participates in the GBBC—families, teachers, and young people—will get a chance to hone their observation skills, learn more about birds, and make a great contribution to the future!”

Anyone can take part in the Great Backyard Bird Count, from novice bird watchers to experts. Participants count birds for as little as 15 minutes (or as long as they wish) on one or more days of the event and report their sightings online at www.birdcount.org. One 2009 participant said, “Thank you for the opportunity to participate in citizen science. I have had my eyes opened to a whole new interest and I love it!”

Female ducks have evolved an intriguing way to avoid becoming impregnated by undesirable but aggressive males endowed with large corkscrew-shaped penises: vaginas with clockwise spirals that thwart oppositely spiraled males.
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“In species where forced copulation is common, males have evolved longer penises, but females have coevolved convoluted vaginas with dead-end cul-de-sacs and spirals in the opposite direction of the male penis,” said Patricia L.R. Brennan, lead author of the paper and postdoctoral researcher in the Yale Department of Ecology and Evolutionary Biology. “This coevolution results from conflict between the sexes over who is going to control fertilization.”

The research builds upon a 2007 Yale study that first described the strange morphology of a duck’s sexual organs. While most birds have no phalluses, ducks turn out to have relatively large, flexible penises—up to 20 centimeters—tucked inside their bodies. During sex, male ducks extend, or evert, their phalluses inside the female. Brennan and her Yale colleagues used high-speed video to document the erection of the duck penis for the first time and found the whole process takes less than half a second—an act the Yale team described as “explosive.”

Read more: Yale researchers revel secrets of duct sex: It’s all screwed up

More Information:
Explosive eversion and functional morphology of duck penis supports sexual conflict in waterfowl( paper )

Male birds typically outshine the females, but in some cooperative breeders females have evolved to outshine the males.

Darwin noted that sexual dimorphism (differences in male and female traits) generally leads to elaborate-looking males and dull females because reproduction is shared more equally among females than males. As a result, males need fancy duds to compete with other males for the attention of female mates.

In some species, however, females compete as intensively as males for reproductive opportunities. This takes place among species that live in family groups, known as cooperative breeders, in which not all individuals have the chance to reproduce. Scientists believe that in many cooperatively breeding species, not only does reproduction vary inequitably among males, but also among females. Because of this unequal reproduction among both sexes, females must also compete for reproductive opportunities.

read more Reproductive skew and selection on female ornamentation in social species