Tag Archives: biology

Could ducks in the water melt ice?

Posted on by
11
Female Wood Duck in Chicago in the winter.

Female Wood Duck in Chicago in the winter.

A reader question today! Dolores asks: Would the body heat of a modest mixed gathering of water birds (gulls, ducks etc) melt ice at the edges of a pond?

The answer to this depends on context. We can start by establishing some extreme end-points: one duck at the edge of a huge lake in way-below-freezing weather would not be able to melt any ice.

Female Common Goldeneye in Lake Michigan: it's a good thing the lake is already melted, 'cos you're not going to melt anything.

Female Common Goldeneye in Lake Michigan: it’s a good thing the lake is already melted, ‘cos you’re not going to melt anything.

Twenty ducks splashing around spiritedly in a kiddie pool with the barest skin of ice in weather just at the freezing point would probably, if you waited long enough, cause the ice to melt.

Between our two endpoints are more “normal” circumstances: a group of waterbirds hanging out at a pond. Could they melt any ice?

Continue reading →

Ghost junco

Posted on by
3

ghost1

Isn’t he beautiful? He was caught in the hills in Marin County, not all that far from me, and kept in captivity until he died in 1931.

You might think he’s purely colorless at first glance, but he isn’t. He’s more blue-silver than white, an incredible color to come shining out of a drawer of junco specimens when you’ve just spent the last few weeks measuring the same brown-and-black birds over and over. When you look close you find that hidden in those pale feathers are the whispers of normal junco coloration.

Continue reading →

Adoption in birds (really!)

Posted on by
14

Sometimes the titles of scientific papers are so surprising that they seem to transform into news headlines in my head:

Adoption of chicks by the Pied Avocet – Adoption of fledglings by Black and Red Kites – Caspian Terns fledge a Ring-billed Gull chick – Adoption of young Common Buzzards by White-tailed Sea Eagles

How can this be true? Raising chicks is hard; it takes energy and time and risk. Why would any bird make those sacrifices for an unrelated chick?

Okay, I would absolutely adopt this guy. Pied Avocet chick. Photo by Keith Marshall

Okay, I would absolutely adopt this guy.
Pied Avocet chick. Photo by Keith Marshall

Continue reading →

Red finch, orange finch, yellow finch

Posted on by
14

In general, we understand red birds thusly: the brighter the red, the better the bird. (Why? See this post.) The better the bird, the better his genes/parental care/mate, and the better his reproductive success.

But sometimes it’s more complex—and interesting—than that.

Red male House Finch. Photo by M. LaBarbera.

Red male House Finch. Photo by M. LaBarbera.

Yellow and orange male House Finches. Photo by Ken-ichi Ueda.

Yellow and orange male House Finches.
Photo by Ken-ichi Ueda.

Continue reading →

Funny-looking birds look like that for a reason

Posted on by
3
ARKM the Dark-eyed Junco showing off his perfect birdiness. Photo by M. LaBarbera

ARKM the Dark-eyed Junco showing off his perfect birdiness.
Photo by M. LaBarbera

I think we can all agree that the junco is pretty much the Ideal Bird. Ask any small child. Brownish, feathers all over, small round body, short neck, cute twiggy legs, little triangle for a bill: that’s what a bird looks like.

Um...

Um…

Or not. None of the following birds look like a small child’s quintessential Bird, because these birds—with their spoonbills, mustaches, and scary dinosaur feet—are awesome weirdos.

Continue reading →

Think like a scientist: human-driven selection

Posted on by
6

A salmonella outbreak on chicken has hospitalized over a hundred people so far. Salmonella is on a lot of chicken; if you cook chicken at all regularly, you have definitely purchased and handled salmonella-tainted chicken. But that’s okay, because you cook it, and the bacteria die from the heat, and then the chicken does not kill you. No worries!

This chicken might want to kill you... Photo by Ido Mor

This chicken might want to kill you…
Photo by Ido Mor

Except that those 100+ sick people probably weren’t eating chicken sushi. Even if they did all manage to undercook their chicken, there’s this: a Costco found salmonella on its rotisserie chicken after they were cooked at 180 Fahrenheit. Chicken is “safe” when it’s cooked at 165 Fahrenheit, so 180 should be extra safe. Now, I’m not a salmonella investigator; maybe Costco lied about its cooking temperature, or maybe someone handled raw chicken and then the rotisserie chicken and that’s how they got contaminated. But there is a third option: maybe a strain of salmonella has evolved, under selection driven by you and me and everyone else who cooks their chicken, to survive cooking.

We all know what natural selection can do, how the pressure of competing with other individuals and evading predators and finding food and staying the right temperature so that you can make the most babies can drive the evolution of “forms most beautiful and most wonderful” (Darwin).

A form beautiful and wonderful: male greater kudu in Kenya.

A form beautiful and wonderful: male greater kudu in Kenya.

Continue reading →

The amazing fox domestication experiment; or, how your puppy got floppy ears and a waggly tail

Posted on by
3

More than fifty years ago, Russian scientists began an experiment in domestication. At that time, silver foxes had been raised for fur for about 100 years already, so their care and breeding was well known. The scientists began their project like this: they would approach the cage of a silver fox and note its response. The fox would crouch, ears flattened, snarling in fear, or else back away as far as it could until its body was vertical against the back wall of the cage. All of the foxes were frightened of the humans—but some less than others. The scientists chose the foxes that showed the least fear of humans, and bred them. Then they did the same with the pups, raising up and breeding the least-frightened of them; and so on and so on.

Young wild silver fox. Photo by Matt Knoth

Young wild silver fox. Photo by Matt Knoth*

The original foxes were as close to wild animals as anything can be after being bred for fur for a century. Their descendants, after many generations of selection for just one thing—tameness, a liking of humans—look and act like dogs. They seek out humans, they whine and lick your face, they wag their tails. They even look like dogs—mostly, like border collies.

Fox kit showing the white markings characteristic of domestication. Photo by Luz Rovira

Fox kit showing the white markings characteristic of domestication. Photo by Luz Rovira*

Continue reading →

The nest that came back from the dead

Posted on by
19

This summer we have lost nests to logging, cows, and natural junco predators. None of those shocked me. A pinecone as death-dealer, however, was a surprise.

2013_NCB1When I took this picture, I thought that this nest was dead. The chick you see was completely motionless and stone cold. The pinecone—which was not supposed to be in the nest—had (we think) prevented the female from warming her chicks up, and without their mother’s warmth these very young, naked chicks quickly got too cold.

But when I took the pinecone out to count chick bodies, one of the bodies moved. My field assistant and I took the chicks—there were three, all as cold as the morning mountaintop air—in our warm hands. I still thought they were probably dead: recently dead things may twitch when disturbed.

But as the tiny bodies began to feel less chilly, they squirmed more and more.

2013_NCB2 Continue reading →