About toughlittlebirds

I'm a graduate student in the Museum of Vertebrate Zoology at UC Berkeley. I'm interested in why animals do what they do. Disclaimer: I don't speak for UC Berkeley or the MVZ in anything I write - if you don't like something, I'm the only one to blame!

Another delightfully anomalous junco

Readers who have been with me a while will remember “Buddy,” the white-spotted male junco who lived near my workplace for years. Unusually-colored juncos aren’t as rare as, say, the recently-spotted yellow cardinal, but they aren’t common either. (In my field work in the Sierras we banded ~500 juncos, and only one had a color abnormality.) As a lover of both rare birds and juncos, I get pretty excited about them when I find them.

This particular junco flashed up out of a bush as I was walking past. The size, tail, and movement pattern all said “junco”—but when the bird landed in a tree and I got a good look, my brain’s bird-ID function got confused: “Big chickadee!” it suggested. “Small kestrel! Big-small-chickadee-kestrel-junco!”

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When forbidden love creates a new species

Choosing your mate is an important decision. If you are a species that cares for your offspring, you and your mate need to be able to coordinate your care, and you must be able to rely on your mate to pull their weight. (Watch the albatross cam to see how the mated albatrosses depend on each other—one stays back with the chick while the other flies off to get food. If the food-getter never came back, or the chick-minder wandered off, the chick would die.) More fundamentally, whether or not you care for your offspring, you and your mate must be able to have biologically healthy offspring together.

Animals do not always get this right. The recently-in-the-news stories of Thomas the goose, who bonded with a black swan and spent his days helping that swan and his mate raise their cygnets, and Nigel the gannet, who was devoted to a concrete gannet dummy, are good examples of the errors an animal heart can make. From an evolutionary perspective, these are bad decisions: they prevent the lovestruck individual from passing on their genes to future generations. (All reports suggest that Thomas and Nigel appeared happy, so from an individual perspective, the mistake may not be so bad.)

But sometimes—very, very rarely—an error in mate choice, instead of being an evolutionary dead end, is the beginning of an entirely new lineage.

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Sea urchins are giant eyeballs covered in spikes

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Photo by jayhem on flickr, used via a Creative Commons license.

Sea urchins do more than you might expect from a spiky ball. They seek out holes to hide in, travel in search of food, cover themselves in costumes of seaweed and rocks, and flee their slower predators. (Even the speediest urchin can’t flee a sea otter, but it has a chance against a sea star.)

All of this is a bit astonishing for an animal that has no eyes. How do they spot their hidey-holes? How do they see the sea stars in time to run away?

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Young red-tailed hawk vs. the ice

It’s a bright, cold morning just after the first real snow of the season. The chill gives your hunger an edge, but you have a plan: sit on the trash can and wait for the squirrels to come to you.

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This perch is perhaps not entirely suited to your dignity, but it is hardly your fault that your fuzzy-tailed food likes to hang out in the garbage. They have chewed a hole in the side of the trash bin for easier access to their scraps. You, although temporarily perched on a trash bin, are death on wings—sharp talons screaming down from the sky…

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Banding station highlights are small and fuzzy

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The sun rising behind the mist nets at the banding station.

‘Tis the season for year-end “Best of” lists, so I thought I’d do something of the sort for my 2017 banding station birds. Except it turns out that we had too many cool birds this year to fit in one blog post, so I’ll be doing a series of banding station highlights posts. First up: the small and fuzzy.

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Female Golden-crowned Kinglet

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The massive/tiny scale of ancient DNA

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Wild tuco-tuco. Photo by Anand Varma, former member of my lab; http://www.varmaphoto.com/

Take a tooth. Leave it in a cave for 5000 years. Retrieve it and examine the tooth: after all that time, those seasons passing and bacteria working away, what is left of the original animal? Not a lot; but not nothing.

There remains still some DNA from the original owner of the tooth, but degraded, fragmented into little pieces, and overwhelmingly outnumbered by the DNA of all the bacteria that have grown and reproduced and died in the tooth. Finding the DNA of the original animal would be like finding a needle in a haystack—if the haystack was really big and the needle was also a piece of hay, just slightly different from all the other hay.

And yet: we can do it.

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