Last November, I posted a blog about our Allegheny Woodrat (Neotoma magister) project at the Edge of Appalachia Preserve – in case you missed it, you can catch up here.
This fall, our woodrat project is in full swing! A team of researchers including staff from Cincinnati Museum Center and The Nature Conservancy, have been collecting DNA samples for analysis. How do you catch a woodrat? Based on our survey results collected last fall, we conduct 2-night trap sessions in each area we suspect woodrats to be living. Since the rats are most active at night, traps are set in the afternoon and checked first thing the following morning. We use rectangular wire mesh traps with a trip platform – when the rat enters and steps on the platform, the door closes. The traps are baited with apples and “rat blocks” (similar to dog treats you might give your pets), and a square of cotton bedding for the rat to snuggle up in while waiting to be rescued. The rat is not harmed in any way by the trap.
We got one! This is what a typical trap site looks like – usually in deep cracks in the rock face or under rock ledges.
When a rat is caught, we open the trap and let the rat enter a “handling cone” – a plastic mesh cone. The rat goes in nose first and we clamp the cone closed behind it to pin the rat in place. This is safer for everybody – it keeps the rats still during sampling so they don’t injure themselves or us. For each rat, we get a weight, sex, and DNA sample. To collect DNA, we use a tool that looks like a cross between a paper punch and nail clippers to punch two small, circular pieces of skin from the ears. The rats barely seem to feel it, and there is very little bleeding. I’d have to imagine it feels like getting your ears pierced. It’s a noble sacrifice for individual rats to allow us to better understand and protect the health of their population. We always sample the rats over an old pillowcase so we can find the tissue punches when they fall – it also helps us to keep track of all our sampling equipment on the leaf-covered forest floor. The tissue samples are put in a vial of alcohol to preserve them for DNA testing.
Coaxing a rat into the handling cone.
Museum staff collecting data on a woodrat.
Collecting the DNA sample.
When we are all done, we open the cone and let the rat go. They don’t always go far, though! If we suspect the rat has been in the trap a while (all the food is gone), we offer them a bit of honey and some more snacks. Sometimes, they hang around and let us get photos while they eat!
Woodrat stopping for a rat block snack after release.
Woodrats are very curious by nature, and we often catch the same rats again on the second night of trapping at a site. They just can’t resist that free meal! When rats are recaptured, we just open the trap and send them on their way.
Recapture! This rat was caught again on night 2 of trapping – the hole punches in the ear are easily seen.
Stay tuned for “Woodrat Hunting, Part 3” when we begin processing the samples in the genetics lab! Because I always forget to take pictures of my own in the field, special thanks to the Edge of Appalachia Staff and the woodrat team for providing photos for this post.
For additional photos and video of Allegheny woodrats taken during our project, check out Life on the Edge, the blog authored by our Edge of Appalachia staff.