Hi, Everyone - I am hoping folks in the iNat community can advise me on how best to approach a small project to track the number and location of ant-lion larvae that dig pits in a patch of soil beside my driveway. I discovered larvae living there last summer. This year I’d like to record their numbe…

As part of my grad work doing plant surveys for the NPS I made up a rig like this out of PVC pipe [Portable survey grid] Each leg is adjustable both in angle and height, so it can sit level on uneven terrain. One marked leg goes on a fixed datum (in my case a nail or spike hammered into the grou…

[image] earthknight: the national park I was working for at the time is still using it. So simple, usable and adaptable! Like, for antlions or whatever we find for time lapse- like even slime molds… Oh gosh, this is why I love this forum, thanks guys! ( @romainclem I should lay in the parts…

Although I do love @earthknight ’s solution, for monitoring your side garden area an easier and more casual approach might be appropriate. Since you aren’t sampling, you don’t necessarily need a grid. I have two options: First Option: You could lay out a bit of plastic garden mesh and peg it to th…

Thank you for your reply, @earthknight . Very cool plans and photo. This would be fun to assemble and use. Naive crafting question: Did you use a tap to cut threads for the set screws? Is gray PVC easy to find, e.g., at Lowe’s or Home Depot? I plan to give this a try, drilling holes and using fine wi…

Thank you, @murphyslab ! Your second option is particularly interesting. I fear that I lack the confidence that I would accurately triangulate the locations of the pits from day to day. Thus, I’m drawn to a grid. However, I’ve noticed pits in a second area close to the first and will try your option …

Well, if you do try the 2nd option, there is a plugin for ImageJ that can transform images based on landmark correspondences here: https://imagej.net/Landmark_Correspondences

Very good. Thank you. I look forward to trying triangulation and using Landmark Correspondences. :)

I got everything at the local hardware store that was near the headquarters of the park I was working at. The color of the PVC doesn’t matter, it’s the diameters that do. If you find PVC of different dimensions that fits together well, then that can be used instead as well. If you want to make a m…

Fun project! I agree with the ImageJ suggestions. I usually add a ruler in the photo. I have used it to measure zebra mussel trails in sand. And also to measure skulls from photographs. Great software.

Thank you for this additional information, @earthknight . I also look forward to trying Image-J.

Advice for observing daily number of ant lion pits

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Advice for observing daily number of ant lion pits

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