Melanic color-dependent antipredator behavior strategies in barn owl nestlings. By Valentin van den Brink, Vassilissa Dolivo, Xavier Falourd, Amélie N. Dreiss, and Alexandre Roulin. Behavioral Ecology, 2011.
I’ve been slacking off on the Featured Papers, since it’s the field season and I’ve been reading almost nothing less than usual; but this paper is too crazy not to mention.
The baby crested geckos are almost three months old now. Both hatched at 1.9 grams; October now weighs 3.3 g, which isn’t bad. (Geckos have a rather different growth rate than juncos, you’ll notice: juncos hatch at about 2 g and are at 3+ the next day!)
October
Poor ROAR. He has good subcutaneous fat and a decent mass (18.6 g), but he looks like he’s having a rough summer.
One of birds’ most endearing qualities has to be their care of their chicks. Sparrows fly in and out of nests in the rafters of gas stations, doggedly exhausting themselves to feed their hungry offspring; ducks and geese lead lines of fuzzy yellow babies across roads and around ponds; and we humans see ourselves in this tender parental care, and say “Aww.”
But child-rearing in birds is stranger than you think.
I now have four-count-’em-FOUR nests to update you on! (Of course my plan was to have twenty or so, but hey, I’ll take what I can get.)
New nestlings! Read on for more. Photo by M. LaBarbera.
If you have ever driven through Yosemite National Park, you’ve seen them: distinctive yellow signs with a silhouette of a bear and the admonition, “Speeding Kills Bears.” Although it doesn’t say so on the sign, each sign is placed where a bear has been killed by a car.
On our last trip, driving through Yosemite on our way home, we saw the truth of this first-hand: a black bear lying dead at the side of the road, his blood still red on the asphalt. He was young, no larger than a St. Bernard. His muzzle was delicate, his ears soft. Like many of the black bears I’ve seen, he was not just black, but had an elegant sweep of blond across his shoulders, like a shawl.
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.
I stayed away from OLLA’s nest for several days, as I promised, so as not to scare the chicks into fledging early; but finally I just had to know if they had fledged yet. As I approached the nest both OLLA and ALGE scolded me—but the nest was empty. I looked around to see why they were angry at me and caught sight of a fledgling in a nearby tree: BABY! I didn’t see BABY’s siblings, but there were lots of trees around, and fledglings can be cryptic if they stay still. BABY was the smallest of the three so if she is fledged and okay, it’s very likely that YAYN and MAYO are doing well too.
YAYN or BABY, from before she fledged.
Another great question from James:
When certain birds (not owls) look out at you from their left eye, they can’t see you with their right eye on the other side of its head. So what do birds with eyes on both sides of the head actually see? Two different scenes? Or some sort of panorama distillation?
What does LAGG see?
Recently I’ve noticed that people are being referred to Tough Little Birds by searching things like “what to do when junco chicks fall out of the nest”—and, of course, finding this blog totally unhelpful. Whoops! I’m fixing that now.
Tough Little Birds 