Birds – Science Sushi

Kelp Gulls Tear Out Baby Seal Eyes So They Can Feast On Their Remains When They Die

A kelp gull waits for an unfortunate pup to die. Photo by Naude Dreyer

I think it’s fairly safe to say that gulls are among the least-loved birds in the world. These loud and annoying seabirds have a disturbing lack of fear of large mammals — including us — and a seemingly insatiable appetite, as any beach picnicker can attest. It’s no wonder that the creators of Finding Nemo portrayed them as mindless feeding machines, the only species in the movie to lack intellect and personality. But they were wrong in at least one respect: while seagulls might be feeding machines, they are far from mindless. Continue reading “Kelp Gulls Tear Out Baby Seal Eyes So They Can Feast On Their Remains When They Die”

Beauty is gene deep: attractiveness in turkeys controlled by gene expression

Male_north_american_turkey_supersaturated — Hubba hubba—just look at the snood on this boy! He doesn’t have stellar genes, though—he just knows how to use them.
Photo via Wikimedia user Lupin.

In all species, some males are simply better looking than others. They have the right shape, dance, color or attitude to make the ladies of their species swoon. It’s generally assumed that good looks come from one thing: good genes. Win the genetic lottery and you’re set. Get a bum hand from mom and dad and, well, you can always try to mate again next year.

In turkeys, male come in one of two varieties: dominant and sexy or subordinate and, well, kind of plain. The dominant males have all the things female turkeys want like lots of bright, red flesh over their beaks. The subordinate males don’t stand a chance with the females, but that doesn’t mean they stand around and do nothing. They actually help get their more attractive brothers laid, thus helping pass along their genes through kin selection.

There was just one thing that didn’t sit right with scientists: how can closely related male turkeys—brothers that share 50% of their DNA—look so different? How can one be drop dead gorgeous while the other is nothing to gobble at? Continue reading “Beauty is gene deep: attractiveness in turkeys controlled by gene expression”

Why did the chicken cross the road? Maybe it was looking for its penis.

Warning: the following may be considered NSFW, particularly if your employer finds avian genitalia inappropriate.

Thanks to the detailed research of Patricia Brennan and the fluent coverage of it by Ed Yong and Carl Zimmer, a lot of people have not only heard of the impressive duck penis, they’ve seen it in all its explosive glory (if you don’t know what I’m talking about, take a moment to click on the links above — trust me, it’s worth it).

avian penis comparison — Why do chickens and other birds lack the fancy phalluses of their relatives? Good question. At least, now, we know how…
Image from Herrera et al., Fig 1.

But while ducks and their fellow water fowl boast these impressive, large penises, the penes of most birds are nothing to squawk about. Ninety-seven percent — over 10,000 species of birds — have either reduced or non-existant penises that are incapable of penetration. “One of the most puzzling events in evolution is the reduction and loss of the phallus in birds,” explains biologist Marty Cohn in a Cell Press Video Abstract. “It’s remarkable that a group of animals would eliminate a structure that is so important for reproduction.” Given that, like us, birds conceive through internal fertilization, you would think a penis would be essential. How else is the male’s sperm supposed to get all up in the female’s vagina?

While scientists still debate about why the chicken lost most of its penis, a new study published this week in Current Biology finally explains how it was lost, a crucial first step in unraveling this evolutionary enigma. Continue reading “Why did the chicken cross the road? Maybe it was looking for its penis.”

Pretty great tits make better mothers

As anyone in Europe knows, pairs of great tits aren’t hard to find. They’re really everywhere, if you keep an eye out for them — great tits can be found from the northern coast of Africa all the way to western central Russia, and in between. Bouncing around without a care in the world, great tits are one of the most popular and well known birds in the world. Yes, I’m talking about the birds, guys. The pretty, charismatic, if not slightly murderous birds.

Great tits have become a wonderful research model for scientists, as their widespread distribution and general lack of fear of people makes them easy study subjects. There are literally thousands of published papers looking at their ecology, behavior, genetics, and evolution. But while scientists have been studying these colorful, engaging birds for about a century, there’s still a lot to discover. Just last month, scientists from Palacky University in the Czech Republic learned something new, and incredible, about female tits: the prettier the mother, the healthier the offspring. Continue reading “Pretty great tits make better mothers”

High-Speed Evolution: Cars Driving Change In Cliff Swallows

cliff_swallow_nest — Cliff swallows in their nest

I imagine that adjusting to life around humans, with all our buildings and fast-moving transport mechanisms, is tough for a bird. It’s estimated that some 80 million birds are killed in motor vehicle collisions every year, and with an ever-growing population of people driving around and paving roads in more remote areas, things must be getting harder and harder for the animals we share our world with. But, the American Cliff Swallow (Petrochelidon pyrrhonota) isn’t one to let people ruin the neighborhood. More and more, their huge nesting populations can be found in man-made structures like bridges and overpasses, and have even become cultural fixtures in areas like California. Their new nesting sites allow them to survive even as their former habitat disappears, but it comes at a cost: by living near roadways, the birds are more at risk than ever of being on the wrong end of an oncoming vehicle.

Continue reading “High-Speed Evolution: Cars Driving Change In Cliff Swallows”