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Monthly Image: Orb-Weaving Spider

Once again, the season of orb-weaving spiders has arrived, with this one building her web across a living room window:

Orb Weaving Spider - with insect

Orb Weaving Spider – with insect

I set the Sony HDR-AS30V atop a tripod, told it to take photos at 5 second intervals, then stitched the images into a Youtube video. It won’t go viral, but watching the spider construct her web over the course of two hours was fascinating.

She finishes the spiral at about 1 m video = 1.25 h real time, settles down for what might be a nap (it’s hard to tell with spiders), and has an insect join her for supper at 1:28, half an hour later.┬áSpiders go from “inert” to “death incoming” almost instantly, even in real time running.

Another orb weaver set up shop in the adjacent window, but moved out the next day. Perhaps there’s a minimum spacing requirement?

Two more orb weavers guard windows in the kitchen and laundry room. We sometimes leave the lights on for them.

YouTube has other web-building videos with far more detail, of course.

The magic incantation to create the video from a directory of images in the form DSC01234.JPG:

sn=1 ; for f in *JPG ; do printf -v dn 'dsc%04d.jpg' "$(( sn++ ))" ; mv $f $dn ; done
ffmpeg -r 15 -i /mnt/video/2017-09-03/100MSDCF/dsc%04d.jpg -q 1 Orb-Weaving-2017-09-03.mp4
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  1. #1 by Keith Ward on 2017-09-15 - 20:32

    Looks like an arboreal orbweaver (neoscona crucifera) – “Common Spiders of North America” by Richard Bradley. So amazing to watch the nightly construction. We had one in the same location as yours (living room window) for a while, and would see her drop down nearly every night to go to work. If you really want to see impressively fast action with catching prey, see if you can find a shamrock orb weaver or a marbled orb weaver sometime. They are orb weavers, but do not hang out in the center of the webs like most of them during the day, however they might at night. They will seemingly drop out of nowhere when something gets caught in the web, it resembles a very controlled fall and is usually startling. They typically hide under a leaf that has been curled using silk. While out on our walks, I usually spot a few strands of the support silk first and follow those up to their lair and then confirm if anyone is home.

    • #2 by Ed on 2017-09-16 - 09:34

      Mary holds her basket in front of her during her first walk into the garden: the spiders lay astonishingly strong anchor strands across the pathways at head height. So far, they haven’t tried to capture her, but … http://www.nytimes.com/2007/08/31/us/31spider.html

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