Tag Archives: biology

Another freelance science mouse

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A few months ago, my labmates who study chipmunks enlisted the help of one of my pet mice to test-run a chipmunk-monitoring device that they are hoping to use in the field this summer. That went well, and now they’re calling on another one of my mice for a simpler test: to see how long the glue they’re planning to use will keep their device attached to rodent fur. They want glue that will stay attached long enough for them to get good data, but not so long that the monitor becomes a permanent part of a chipmunk’s life.

Since chipmunks spend a lot of time in burrows, we chose my most burrow-loving mouse, who likes to spend all of his time hiding underneath things. He was not pleased to be forced out into the open.

Porter with the test chip glued to his back

Porter with the test chip glued to his fur

So far he hasn’t seemed to care a bit about the chip. However, he is quite annoyed that I now dig him up daily to check whether it is still attached. He’s not really a people mouse.

PLEASE just leave me alone.

PLEASE just leave me alone.

Much better.

Much better.

Animal April Fools

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Oh no! I broke my wing! I’m so injured and defenseless and tasty!

Look how broken my wing is! Are you looking? Ooh, it stings!(Photo by Glenn Loos-Austin)

Look how broken my wing is! Are you looking? Ooh, it stings!
(Photo by Glenn Loos-Austin)

Ooh better follow me as I flop brokenly over this way!(Photo by Ken Slade)

Ooh better follow me as I flop brokenly over this way!
(Photo by Ken Slade)

Ouch ouch! What a flailing broken mess of deliciousness I am being over here!(Photo by Jon Rutlen)

Ouch ouch! What a flailing broken mess of deliciousness I am being over here!
(Photo by Jon Rutlen)

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The incredible story of the Black Robin

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This is the Black Robin (Petroica traversi), a species found only in the Chatham Islands, New Zealand:

Black Robin. Photo originally by schmechf, modified by Wikimedia Commons.

Black Robin. Photo originally by schmechf, modified by Wikimedia Commons.

This was the total world population of Black Robins in 1980:

black_robin5

Five birds. That’s not great—and it gets worse. Guess how many of those were adult females?

One.

Almost any conservationist would tell you that this was a hopeless situation. You can’t restart a species from one female—especially when that female is a whopping eight years old already, in a species that generally lives four years.

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Dinosaurs probably looked just as awesome as you think they should have

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When you’re little, you play with toy dinosaurs all bright red or blue or painted spotted with many colors. You fill coloring books with purple velociraptors taking down plaid apatosaurs. Then you get older and learn about camouflage; and you watch nature documentaries of brown felines taking down brown gazelles in tall brown grass; and—zebras notwithstanding—you start to think that probably dinosaurs weren’t plaid after all.

Well, buck up! They—at least some of them—probably did look really awesome.

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Learning how to eat like a bird

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When you’re an altricial baby bird, life is either great or over. If it isn’t over—that is, assuming you aren’t eaten by a mouse, chipmunk, snake, slug, coyote, etc.—then your life is sitting still in the warm and having food shoved in your face. Excellent.

Reed Warbler chicks. This is the life.Photo by nottsexminer

Reed Warbler chicks. This is the life.
Photo by nottsexminer

But that doesn’t last. After you fledge, your parents keep feeding you, but soon they start feeding you less. You can follow them around begging, but soon even that doesn’t do any good. You have to face it: you need to learn how to catch your own food. But that food flies and crawls and runs away!

Doesn't matter. I can catch it.Photo by David Mikulin

Doesn’t matter. I can catch it.
Photo by David Mikulin

We tend to think of wild animals as “instinctually” being able to do everything they do, but in fact, a lot of those skills have to be learned and practiced. Two of my favorite scientific papers looked at how fledgling birds developed their foraging skills. As adults, they were the expert bug-catchers you see all the time; but as fledglings, they did—well, about as well as the four-year-old child of a champion fisherman would do, the first time you handed her the fishing rod.

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Badges of status, or, keeping House Sparrows honest

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In many bird species, the males have to acquire and defend a good territory – filled with great food or great places to put a nest – in order to have a prayer of attracting a mate. There’s even evidence that some females pay more attention to the quality of the male’s territory than to the quality of the male, so having a good territory is a big deal.

In these species, males fight a lot. They fight to get territories and then they fight to keep them. It’s a bit like a football game: you have to run fast and smash into people in order to get the ball, and then continue running fast and smashing into people (and withstanding them smashing into you) in order to hang onto it.

Male House Sparrows fighting.Photo by Jessica Lucia

Male House Sparrows fighting.
Photo by Jessica Lucia

Take that!Photo by Jessica Lucia

Photo by Jessica Lucia

All that fighting takes a lot of time and energy, not to mention risk of injury. So the birds (and many other resource-defending animals) have found a less-dangerous shortcut: instead of fighting, they wear “badges of status,” color markings on their body that stand for how tough they are. Birds with less-tough badges don’t bother challenging the tougher birds, and everyone has to fight less. Sounds great, right? It’s the equivalent of a football player wearing a jersey that says “I’m Tougher Than You,” and the other football players just leaving him alone. So much less violent!

… but it doesn’t seem like it should work, does it? If it did, then anybody could put on a jersey that says “I’m Tougher Than Everybody” and win the Superbowl. What stops the birds from lying?

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Avian flight I: built for flight

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Laughing Gulls in flight

Laughing Gulls in flight

Everything about avian morphology has been shaped by the requirements of flight. Flight is hard. Animals are heavy, being largely composed of water, and air is not dense; you have to work hard to generate any force by manipulating air. The problem for any flying animal is to be light yet powerful – and to still be a viable animal, capable of eating and storing energy and making babies. A hypothetical weak but extremely light animal – think an air-jellyfish – might be able to fly, but would probably starve. While the ocean is filled with floating particles that real jellyfish can catch simply by passively floating, the air is not so bountiful. (You could argue that web spiders filter-feed in air, but… all right, I don’t know if air-jellyfish are impossible. I think we’re getting off-topic here.)

Air-jellyfish floating in a pink sunset.(Or, Northeast Pacific sea nettle in an artistically-lit tank at the Shedd Aquarium.)

Air-jellyfish wafting through a pink sunset.
(Or, Northeast Pacific sea nettle in an artistically-lit tank at the Shedd Aquarium.)

In any case, birds didn’t start out as light, thin, filmy creatures. They started out as small raptor-y dinosaurs. Natural selection acts only on the traits that are present: massive change to the shape of an organism is hard. (Not impossible! But comparatively rarer.) Birds started out with backbones, four limbs, a head, two eyes, etc., and they evolved flight from that initial morphology.

But how do you make a dinosaur that can fly? Dinosaurs are strong, yes, but they are heavy. Bones are heavy; muscle is heavy; fat is heavy; teeth are heavy.

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Bird dances for two

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The birds of paradise have been getting a lot of attention lately for the elaborate courtship dances of their males, and nobody is going to argue that they don’t deserve it. But it isn’t all “males dance, females judge” in the avian world. The displays of male birds of paradise reflect high reproductive skew: a few males mate a lot, a lot of males never mate. It’s worth it to the males to devote incredible amounts of energy and resources to attracting females, because if they’re successful, they may sire many chicks. They can afford to spend all that energy and resources on crazy feathers and tricky dance moves because that’s all they have to do, parent-wise: they don’t help females build the nest or incubate the egg or raise the chicks.

Male Greater Bird-of-paradise. Photo by Ivan Teage.

Male Greater Bird-of-paradise. Photo by Ivan Teage.

But birds are diverse; the birds of paradise reflect just one point on a spectrum of mating systems. Near the other end are birds with low reproductive skew. Males of these species look pretty much like the females, and they contribute about equally to parental duties. You might expect that these species would lack dances the same way they lack meter-long curlicue tailfeathers, but some of them have dances every bit as formalized and elaborate as the birds of paradise. The difference is that these dances are duets.

Laysan Albatross pair performing courtship dance. Photo by Michael Lusk.

Laysan Albatross pair performing courtship dance. Photo by Michael Lusk.

(Note on videos: I know clicking on videos is annoying. But it’s worth watching the videos in this post, I promise.)

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5 bad-but-good things about field work

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No food that you can’t cook by adding boiling water or wrapping it in aluminum foil and sticking it in a campfire. On the one hand, you’d be surprised what turns out to be delicious wrapped in foil and cooked in a campfire—mushrooms, tomatoes, peaches, spinach—and you get to eat a lot of s’mores and Nutella.* And you gain a real, passionate appreciation for kitchen-cooked food; my field assistants and I can spend hours rhapsodizing about the food we wish we were eating. On the other hand, we make ourselves desperately hungry for pesto and pizza and Homeroom mac&cheese, and then have to eat dehydrated black bean soup. And the food appreciation never seems to last long enough for us to appreciate it when we actually have kitchens. Case in point: I’m at home now, capable of making all sorts of delicious things that I’ve craved while in the field, and I’m having a root beer float for breakfast.

*Unless you’re doing really serious, backpacking-type field work, in which case no fresh fruits or Nutella for you! Dehydrated soup all day, every day. That’s pretty rough.

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