Scary birds

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.)


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.

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Think like a scientist: correlation

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

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.

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Blood secrets

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.

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