Night moves

Our spiders are very quiet during the day, but we noticed that every morning their cages were full of fresh cobwebs. We knew they were sneaking around at night, and we resolved to catch them at it. A student, Ade Atolani, and I put together a gadget so we could watch.

We got a Raspberry Pi with a NoIR camera, drilled a hole in a plastic cage, and mounted it above a spider. I had no idea if this would work adequately at all — would we have enough resolution to even see the spider? How effective was this camera at seeing in the dark anyway? — so we just slapped together a quick trial run. We turned everything on late one afternoon, told the Raspberry Pi to take a picture every 60 seconds, and let’s see what we get. Miraculously, it all worked, first try.

What you’ll see in the video is a rectangular wooden frame in a cage, and we’re looking down on it. There’s a nice velvety dark cloth on the bottom, to minimize glare and reflections. At the beginning, there’s diffuse light from the window, so the infrared camera isn’t kicking in yet, but when it gets dark enough, the IR lamps automatically switch on, and the purplish black cloth looks pink. The important thing is that we can see the spider all night long, as it goes through bursts of activity. Awesome.

It looks like we’re going to have to sample at a higher rate, because the behavior is very bursty. We’ll enclose the whole set up in a light-proof box to get rid of the extraneous light. I also want to try some side illumination with an IR lamp to see if we can resolve the webbing as it goes up. This was just a pilot experiment, but it’s very promising.

Good morning, babies!

It’s time to get an apartment of your own!

On the left in this vial you can see the egg sac; on the right the black shriveled thing is a mealworm that was consumed by Mom. Mom has been moved out already. All those little black dots everywhere? Baby spiders. I’m going to have to go remove that foam plug now, and quickly sort ’em all out.

Quick! Do some community science before winter strikes!

There are two fun projects you can do right now.

  • #Invertefest begins today! All you need to do is wander around your home or parks or wherever and take photographs of any invertebrates (mammals, birds, reptiles, amphibians, and fish do not count) and post them. Any invertebrates! It doesn’t have to be spiders! You’ve got bumblebees in your yard, cockroaches in your kitchen, lice in your hair, those are all good.
  • Eight-Eyed Expedition is a new one. They want you to get out and observe California tetragnathids, a kind of orb-weaving spider. They’re easy to recognize with their long skinny bodies. You can also photograph them and post them, but there’s an additional request: they want you to write to them and request a collecting kit. They’ll send you vials of alcohol and more instructions, and in this case what they want you to do is find them, photograph them, record their exact location, and then kill them humanely and send their little preserved bodies back to Berkely. This does seem to be a California-exclusive project, which breaks my heart because one of the things they’ll give you is a “Certified Arachnologist” sticker, and I ache for the validation.

At least I’m going to get out and take photos of Minnesota invertebrates today, even though my wife snuck around and erected another bird feeder right outside my office window.

This vertebrate does not count.

#InverteFest is coming

This weekend! If you’re wondering what Invertefest is, it’s an excuse to crawl around and get on your knees and get dirty rummaging around your house and yard and the park, looking for all kinds of miscellaneous invertebrates. If you’re on the coast, get out to the beach! The whole point is just to notice all the bugs and spiders and jelly fish and worms and beetles and grubs and flies that surround you. The instructions:

  1. Find invertebrates. This can be in your basement, your yard, the local park, the beach, an alley or anywhere near where you live.
  2. Share observations. Share photos, videos or art of your discoveries on Twitter using the hashtag #invertefest.
  3. Interact. Search the #invertefest hashtag for tweets and share, comment and learn.
  4. Bonus – citizen science. To contribute your observations for science, upload your photos to iNaturalist.

Huh. I do all that all the time already. I guess I’ll just do it more this weekend.

Safety first

Since we’re doing a lot of scouting around on country roads nowadays, I decided our car needs a warning sticker.

I’m wondering if it’s enough — maybe I should get some roof-mounted flashing yellow lights?