I wrote about birds and mirrors a while ago, and not much has changed scientifically since then. Most bird species tested have interpreted their own reflections as other individuals, responding either with aggression or courtship. Female pigeons who view their own reflections ovulate, apparently interpreting their reflections as suitable mates. Among birds, only magpies, so far, have been demonstrated to understand that the mirror reflects their own image, although pigeons can be trained to use spatial information from mirrors correctly in the real world.
So why bring this up again? Recently I saw a Yellow-rumped Warbler interacting with its reflection in a car side mirror, and took a video with my phone. Here it is (apologies for the lack of zoom):
At the time I took the video, I didn’t think much of it beyond general amusement. But rewatching it, I began to have some questions.
Egrets are beautiful, especially in their breeding plumage, when they sport long curved plumes and dramatically colored faces.
Great Egret displaying breeding plumes and a green face.
Snowy Egret with similar plumes and a red face.
Those breeding plumes are so beautiful that demand for them—for decorating women’s hats—almost drove egrets to extinction, and concern for the heavily persecuted egrets is what gave rise to the bird conservation movement in the early 20th century.
Egrets earn those luscious plumes. Before they get to be adults in breeding plumage, egrets must survive a cutthroat childhood in considerably less impressive dress.
Yikes, THAT’S what our chicks look like??
Grandmothers are an evolutionary mystery.
Well, not grandmothers exactly: rather, women who have passed menopause. Human men can sire children as long as they live, but human women can’t have children after they go through menopause. But why do we have menopause at all—why stop having babies? Isn’t it always better, evolutionarily, to have more babies?
I don’t know, this might be too many babies…
The mystery is far from solved, but we have some good clues.
We were searching for junco nests when I heard the unmistakable tic-tic-tic of junco alarm chipping. We followed the sound a ways and found a pair of juncos perched on a low branch, alarm chipping for all they were worth. Strange of the juncos to be alarm chipping at us when we were so far away, before, I thought. I wouldn’t have thought they’d see us as a threat from that far away. Odd birds. Directly below the branch with the agitated juncos was a small shrub. “The nest will be in there,” I predicted, showing off for my new field assistants.
I parted the prickly branches, and tiny pink beaks gaped hungrily at me. “There they are,” I said, pleased with myself. “Three chicks.”
And just as I said that, I saw the snake.
I’ve been neglecting my blog-writing duties lately, preoccupied with the annual Big Grant Proposal Deadline. My grant proposal is on sexual selection in juncos. What part of juncos is sexually selected, you ask? Why, that flashy tail, of course! They’re practically peacocks!
LANK showing off his sexy tail
You’re not quite there yet, little one…
I’ve also been TAing a class on animal behavior, so while I don’t have many extra words to spare right now—I need them all for that grant proposal—I do have a wealth of animal videos that have been brought to my attention by my fellow animal behavior fans. Please accept some videos in lieu of words.
Here is a video of a bird even drabber than a junco who attracts females with his sexually selected aesthetic tastes in things like flowers, shiny beetles, and slightly… er… less attractive items as well: the Vogelkop Bowerbird.
And here are some flies that—well, you should just watch it to believe it. It starts with them gulping air bubbles into their heads, and that’s not even the weird part.
Why are they like that? Sexual selection! Females in this species prefer their males as hammerheaded as possible.
Hey, why not?
Despite pop culture’s image of the scientist as solitary genius, hidden away in his office surrounded by old coffee cups and rat mazes, with escaped fruit flies whirring around his head while theories fizz in his lonely brain, scientists can be quite social. Networking is important in science: it’s how you get jobs, find collaborators, and see new ways to think about your data. (Of course, the networking you’re doing is with other scientists, so escaped fruit flies may still be involved.) This week I’m attending the conference of the International Society for Behavioral Ecology in order to do just that, and the prospect of networking myself has made me think of other animals who network and the benefits they get from it.
Animals interact visually all the time. Males try to look big and scary to rivals, or sexy to females. Prey animals try to look inedible—or better, invisible—to predators. Sometimes these animals use visual trickery to assist their cause.
You’ve probably encountered visual illusions before. Here are some classic ones:
a) The vertical line looks longer than the horizontal line, even though they’re both the same length. b) The top line looks longer than the bottom line, even though both are the same length. c) The middle circles are both the same size, but the one on the left looks bigger. d) The middle grey rectangle is just solid grey, but against the gradient background, it looks like a gradient. e) Both circles are the same shade of orange, but the one surrounded by black looks brighter.
Animals can use visual illusions a) and b) to appear bigger by changing their posture. Vertical stances make you look bigger than horizontal ones, and making a Y with your limbs looks bigger than letting them fall down. So if you’re a male peacock spider trying to look big and sexy to a female, you can raise a pair of back legs up in a Y to look bigger than you really are.
Peacock spider display. Photo by Jurgen Otto*