It’s the time of year for hot chocolate and blankets and pictures of soft, fuzzy, round animals.
House Finch
Pile of mice
Soft fuzzy round warm
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Hurray for California rain
California is in the middle of a severe drought. Winter is the rainy season here, and the last two winters weren’t rainy. The drought’s major human impact has been agriculture-related: California grows a hefty portion of the US’s fruits, vegetables, and livestock, all of which require water. The drive to my field sites takes me through the agriculture-heavy Central Valley, and the drought was clearly apparent this summer. The fields were all cracked dry earth and yellow grass, with the rare irrigated green square standing out like artificial turf. One afternoon late in the field season, a light rain sprinkled as we drove through the valley, and we rolled down the windows and cheered.
The Central Valley is thirsty.
Concerns over agriculture affect everyone; but beyond them, and more personally, I can’t help seeing the drought through the lens of a field biologist.
I have colleagues who slip and slosh through mud all summer to study Black Rails—or who hope that there will be mud to slosh through, anyway, because the small, secretive Black Rail relies on the existence of marshes in which to hide from predators and hatch its comically large-footed chicks. Less rain means fewer and smaller marshes for the Black Rails.
Bats are cool (and generous, and selfish, and fuzzy)
I’ve become more-than-usually interested in bats recently, for extremely serious scientific reasons.
Okay, no. It’s because of this video:
But bats aren’t just cute (and really, what animal wouldn’t be cute wrapped up like a burrito? I challenge you to think of one; even a cockroach would look big-eyed and winning). They are also intelligent, social, and adept hunters.
Does food taste the same to animals as it does to us?
Every day, I feed my cat small, round, hard pellets that look about as appetizing as old gravel, and she gets so excited about them. I tasted one (for you, dear readers!) and I would describe the taste as falling somewhere between the meh of cardboard and the bleh of rancid fish. Not recommended. For her part, the cat flinches if I consume an orange anywhere near her; you can tell she thinks I am disgusting for eating them. It seems pretty clear that she and I have different tastes in food. Are such differences simply matters of individual preference, or is there a biological basis for them?
As in all things, I am right and you are wrong about this.
It’s hard to know what something tastes like to someone else. My personal experience of peanut butter (disgusting) is likely to differ from yours (mmm, yum), despite our belonging to the same species. However, we can say with some certainty that both of us can taste peanut butter, and that it will not taste like lemons to either of us. Humans have five major types of taste receptors: sweet, umami, bitter, sour, and salty. Sugar is sweet, hamburgers and mushrooms are umami, coffee and India pale ales are bitter, lemons are sour, and salt is salty.
And mice are micey.
Let’s talk about bird tongues
Ferruginous Hawk. Photo by Nathan Rupert*
You don’t have to look at many birds to realize that they are very variable in appearance: hawks look different from hummingbirds, and both look different from peacocks. You can spend a lot of time looking at birds, though, before you realize that they are hiding a lot of variation inside their mouths: long tongues, short tongues, spiky tongues, curly tongues, forked tongues, frayed tongues, brush-like tongues.
Like bird bills, bird tongues are specialized to each particular bird’s way of feeding. Birds that feed on nectar have tongues specifically adapted to nectarivory, often with many little protrusions at the tip of the tongue, giving it a frayed or brush-like appearance. This brushiness increases the surface area of the tongue, making it better at picking up nectar.
Rainbow Lorikeet using its brush-like tongue to feed on flowers. Photo by Alan (Kaptain Kobold)*
Bugs of the field 2014: butterflies & moths
IDs always welcome! I do not have the field guides to identify these lepidopterans; let me know if you recognize anyone.
Of all the moths I have encountered, this one, found clinging to the stem of a corn lily, is my favorite. Look at that lovely pattern! Look how fuzzy he is!
Look at that face!
Vampire birds
The vampire strikes again!
Photo by Ian White*
In honor of Halloween, let’s talk about vampire birds.
I am using “vampire” loosely here, the same way people do when they talk about “vampire” bats. These vampire birds are hematophagic (blood-eating!), but do not follow other items of vampire lore: they have reflections in mirrors, can enter your house without an invitation, do not shape-shift, are mortal, and do not sparkle in the sunlight.
Sharp-beaked Ground Finch, Geospiza difficilus
This is one of the famous Darwin’s Finches of the Galápagos Islands. This species is a vampire only on two of the islands, Wolf and Darwin; everywhere else it eats bugs and seeds like a regular finch. Even on Wolf and Darwin, it mostly eats bugs and seeds, but sometimes it craves something a little… richer…
Dum-dum-DUMMMM.
(Sharp-beaked Ground Finch. Photo by budgora*)
Bugs of the field 2014: a bee mimic, colorful beetles, and more
What do birds do when it rains?
I’ve been meaning to write about this topic for a while—now xkcd has beaten me to it:
Oh, well. Since the comic doesn’t actually answer the question, I’m hoping you’re all still interested! (Also, at the end there will be a bonus discussion of ant rain. Yes, ant rain. You won’t find that on xkcd!)
Featured paper: cheating Common Yellowthroats, or, the world is more complex than you think
There is a thing that happens a lot in biology, especially in animal behavior: one set of researchers finds an interesting relationship, like, say, “Birds prefer to eat bugs off of cows with lots of spots, and don’t like to eat bugs off of cows with no spots.” (This is a made-up example.)
Blackbirds flying near a cow, Pt Reyes, CA.
Then, some other researchers do a study and say, “Hey, our birds prefer to eat bugs off of cows with no spots! That’s the opposite!”
Then still different researchers do another study and say, “Our birds don’t care at all about the number of spots, they just care whether the spots make a shape like a smiley face. You guys must all have made a mistake. The Smiley Face Rule is the new Lek Paradox! #nobelplease”
To put it less ridiculously: scientists get different results sometimes, and it can be hard to figure out why. Did someone make a mistake? Who is right? Today’s featured paper takes an example of this confusing scientific disagreement and elegantly makes sense of everything, with the help of this handsome little bird:
Common Yellowthroat (male).
Photo by Dan Pancamo*
Tough Little Birds 