Advice from whales and elephants: listen to Grandma

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...

I don’t know, this might be too many babies…

The mystery is far from solved, but we have some good clues.

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Why do animals lick their fur?

Furry animals can spend a lot of time licking their own fur. Here, a mother sea otter demonstrates:

The simple explanation—that these animals lick their fur to keep it clean—is more or less true, but not nearly the whole story: animals get a lot more out of licking their fur than a stain-free coat.

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Other nests

I’ve seen a lot of junco nests in my four years of field work. Rarely, I’ve been lucky enough to happen upon the nest of something other than a junco. I don’t find enough of these other nests to study them, so they don’t help me in my research—but boy, is it fun to find them!

Quick review: this is a junco nest.

_DSC7120This is not a junco nest:

_DSC6915Some major differences: the junco’s is a ground nest, while this one is a cup nest, suspended above the ground in the branches of a bush. The chicks are covered in light greyish fuzz instead of the junco chicks’ dark fuzz, and are maybe a bit stockier than the junco chicks.

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A predator caught in the act

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.

2015_snake_nest2I parted the prickly branches, and tiny pink beaks gaped hungrily at me. “There they are,” I said, pleased with myself. “Three chicks.”

2015_snake_nest

And just as I said that, I saw the snake.

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Going out with a thud-crack-ow!

I just wrapped up what I think will be my last field work on the juncos for my dissertation. It was quite the eventful trip; I saw a few things I’ve never seen before – but more on that in a future post.

We were trying to catch an unbanded male. He was interested in our playback, but had escaped from the net once already, meaning he was likely to be wary of the net now. When he flew into the net the second time, I ran for him quickly, wanting to get to him before he managed to escape again.

…Or I started to run. Then I failed to clear a large rotting log and went down.

“Are you okay?” one of my field assistants asked.

“I’m not sure,” I answered honestly, from the ground. “Get the bird!”

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Find the nest 4

Juncos love to nest near corn lilies. Usually this means they nest near the base of the corn lily, using the thick stalk and broad leaves as cover. SEAL, however, decided that his nest didn’t need to be near an upright corn lily—and I have to admit that it’s not a bad idea: it took me an extra little while to find this nest, just because it didn’t look like a conventional junco nest location.

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