Monthly Archives: October 2012

Scary birds

Posted on by
10

In honor of Halloween: some birds you would not want to meet in a dark alley at night. (Warning: first two sections contain photos of predation.)

Shrikes

Loggerhead Shrike. Photo by Jeff Jones.

Shrikes are medium-sized birds—the Northern Shrike is slightly smaller than an American Robin—and, upon first glance, fairly unassuming. Perhaps you notice the somewhat raptor-like bill; perhaps the extra notch on that bill, the tomial tooth; perhaps not. But it is only because you are much, much bigger than a shrike that you can afford to be so careless of this fearsome predator.

Continue reading →

Think like a scientist: correlation

Posted on by
1

Correlation does not equal causation. Done!

Just kidding. It isn’t enough simply to state that classic phrase because in the real world, we’re often still stuck with using correlations. If you want to know how lifelong exercise habits affect lifespan, you can’t take two groups of people and force one group to exercise and the other not to (“GET BACK IN THAT CHAIR! That is TOO MUCH walking to the corner store for one day!”), while keeping everything else exactly the same between the groups (“I don’t care if you’re not hungry, everyone eats one cupcake on Tuesdays!”), for their entire lives. Even if you didn’t mind knowing that you, too, would be dead before the study was over, it would be completely unethical. Instead, you study people’s natural exercise habits, and try to correlate them with lifespan. Continue reading →

Featured paper: side-blotched lizards play rock-paper-scissors

Posted on by
3

B Sinervo and CM Lively. 1996. The rock-paper-scissors game and the evolution of alternative male strategies. Nature vol. 380, pp. 240-243.

(Side note: I don’t want to feature-paper too many Science or Nature papers, since those journals are so high-profile that you’re likely to hear about the work elsewhere, and part of the point of this feature is that papers in “lesser” journals can be awesome too; but this paper is classic and fun, so I’ll make an exception.)

Male side-blotched lizards come in three flavors colors: orange-throated, blue-throated, and yellow-throated. Orange males are highly aggressive and defend large territories. Blue males are less aggressive, defending smaller territories. Yellow males look like females and don’t defend territories at all. All three colors compete to mate with females and have offspring. Throat color is highly heritable: orange males have orange sons, blue males have blue sons, yellow males have yellow sons.

Continue reading →

Blood secrets

Posted on by
10

Sometimes doing science feels like doing magic. Take a fantastical witch brewing eye of toad and nightshade flower in a cauldron, substitute a 1.5 ml tube for the cauldron, AW1 Buffer for the nightshade flower, and blood of junco for the eye of toad, and that’s me.

(And that “eye of ___” thing happens in science too: a few of my herpetologist colleagues have been talking lately about what you can learn from preserved lizard eyes.)

One of the things I do when I capture a junco is to collect a blood sample. I use a sterile needle, collect very little blood, and don’t let the bird go until I’m sure the bleeding has stopped. The birds usually don’t even flinch. They act much more upset when I blow on their chests to look for brood patches (I think it feels cold to them) than they do when I take blood.

Me collecting blood from GRAY. The blood moves up the tiny capillary tube on its own. Photo by M. LaBarbera.

Continue reading →

One-eye ROYA, pirate mom

Posted on by
Reply

[Wrote this back in August and forgot to post it—oops.]

ROYA weighs just 16.1 grams, and her right eye is bloodshot and kept mostly closed.

ROYA

That’s bad, but ROYA is one tough little bird. You would never know that she is one-eyed from watching her: she flies, she forages, and she feeds her chick—who is in his young-fledgling, über-needy stage—nonstop. If she can keep it up for another week, he’ll be able to fend for himself, and she will have successfully raised a brand new junco.

ROYA’s young fledgling

I really wanted to band her fledgling, but while he seemed dopy (he cheeped nonstop, letting us know exactly where he was, and let us get maddeningly almost within arms’ reach of him), he knew when to fly, and he never flew into the net either. ROYA is doing a good job.

Think like a scientist: sample size

Posted on by
6

Science is not just for scientists. The methods of thought that underlie science are useful in all sorts of everyday contexts. Most obviously, everyone needs to be able to think like a scientist in order to interpret scientific results—you know, those newspaper headlines like “PAPER CLIP USE MAY LOWER IQ IN PREGNANT WOMEN!!” In that spirit, I’m going to write about some key concepts for thinking like a scientist. Today: sample size.

Pop quiz! You read this (totally made up) report: “Two groups of ten age- and health-matched men were monitored for heart disease. One group was given pet ferrets, while the other was not. The ferret-owning men were 8% less likely to develop heart disease over a five year period.” So: is it time to run out and get a ferret for the sake of your heart health?

You should get a ferret regardless, because ferrets are wonderful. This is my awesome old ferret Zap.

Continue reading →

October in the mountains

Posted on by
6

The field season is mostly over. My field assistants are back in classes; my mist nets are packed away. (Many thanks to the people who kept us fed and equipped by donating a total of $1450 to this field season!) It’s grant-writing, lab work, and data analysis season now.

Well, almost. I really want to know what the juncos do when summer ends. Our working assumption is that they migrate down the mountains to escape the worst of the winter weather, but we don’t know how far they go, or when, or, really, if they do that at all. So this week I went back to look for them.

SOSA, photographed on his territory earlier this year, was nowhere to be found. Photo by M. LaBarbera.

Continue reading →