bat drag, adrian tchaikovsky, stuff on beaches(, plus addenda)
1. Happy Bat Week!
I just think it’s funny that this system for turning off wind turbines to save bats relies on echolocating the bats while the bats are echolocating it
I went down a bit of a rabbit hole googling “bat drag” this morning because I misremembered the They Blinded Me With Science x NYC Queer Birders: Bird Drag event coming up this weekend as a bat drag event instead. Whoops, no, this one is ornithology in drag - chiropterology1 in drag was two months ago, and I missed it!
Apparently most people discussing bat drag are referring to stuff like, NASA says the seams on a baseball lower its drag (as compared to a hypothetical smooth ball). Except maybe if the seams are too high they increase drag instead, according to this "Baseball Dad and Baseball Missionary" who’s just really into baseball aerodynamics.
Of course, I was personally more interested to learn that there are muscles unique to bats that tension their wing membranes, which is helpful because "a slack wing membrane may cause oscillation, similar to a flag, resulting in a substantial increase in the drag".
And now to bring it all together - the US Fish and Wildlife Service requires bat carcass surveys around wind turbines to estimate how many bats are being killed by the turbines, and it turns out you gotta take bat drag into account when figuring out where to look!
“…guidance for the prescribed search radius around turbines is based on limited data. This could result in surveys conducted where bats are unlikely to be found, or limited search areas could cause bat carcasses that land outside the survey area to be missed. Turbine operators need a reliable method to guide survey efforts and determine the appropriate extent of surveys, targeting only areas where bat carcasses are likely to be found around the turbines.” - “Experimental investigation of aerodynamic characteristics of bat carcasses after collision with a wind turbine”
(in conclusion, there’s probably a joke to be made here about searching where the light is and this extremely dissatisfying paper about using UV light to deter bats from getting too close to wind turbines)
2. our memory for a blessing
afaict2 Adrian Tchaikovsky is convinced humanity is pretty much done for, and he’s really just desperately hoping that someone - anyone! - comes after to take our place (and use whatever they can get out of collaborating with our lingering remnants as they move life forward for themselves). Anyone! Maybe spiders? Or robots? How about octopuses and/or slime molds?
Just don’t waste the treasures you can wring out of all the trash we left behind, he pleads. We put in all this work, surely our time here was at least slightly well spent. Please, please let it be true, tell us it was true, please just make it into truth.
3. stuff on beaches is the best kind of stuff
I was super charmed by this story about villagers carefully placing the right kind of rocks out on their beach for these solitary spiders to live under, one by one, after building a road destroyed their habitat.
““When I came to know that our beaches host a unique spider, the only habitat in the country, it made me feel special”, says Veerabhai, a local we met at the beach.” - Conservation Mag
and speaking of things you may happen across on the beach, "[i]t sort of looks like octopuses stuck in the mud, really. But obviously it's tree roots."
"According to Parks and Wildlife it's 40,000 years old, so we thought 'well you don't see that every day, do you'?" - Shane Moore [probably?]
Don’t we? ofc ymmv, but just to say the boringly true thing, I’m built out outta stuff way older than that.
4. addenda on previous posts
re "and suddenly I just really like shrews":
Spiny lobsters also travel in conga lines! But afaict the lobsters only do this during their annual mass migrations, which I was reading about in the absolutely fantastic Wildlife Spectacles: Mass Migrations, Mating Rituals, and Other Fascinating Animal Behaviors by Vladimir Dinets
re "let's talk about teeth, shall we":
Eel larvae (leptocephali) have these wonderfully grotesque big teeth in their itty bitty heads that point outwards and prevent them from even being able to close their mouths.
For a long time, no one could figure out why they had these wacky teeth or what they even ate because their guts always looked empty, but eventually we figured out that they eat marine snow
But also, there’s this idea that “the large forward-pointing teeth of the small larvae seem to be appropriate for grasping large soft particles” - so like, if we wanted to be better at bobbing for jellyfish (and who wouldn’t, really), it’d probably help if we had nasty, big, pointy teeth jutting out of our ever-gaping maws too!
ps their heads come in a surprising range of shapes, so that’s fun
The study of hand wings. Bat wings are basically just long-fingered webbed hands sticking straight outta of their sides, and if this is news to you, you’re welcome!
Let’s pretend I understand an author’s entire oeuvre after reading 3/59 of his books