It’s all about: gender, loggers, ear tags, light collars, and wire color

Our first day out trapping squirrels, I was surprised when we let several of them go, rather than take them back to the lab with us. I assumed that we would take every squirrel to the lab with us, but that’s actually not the case. The experiment dictates which squirrels we need to catch and when we need to catch them.

Gender plays a role in whether or not a squirrel is released or is brought back to the lab. At first, we were interested mainly in female squirrels, but we made note of where we caught any males so that we can locate them when we are ready to start the part of our experiment that involves them.

Whether or not a squirrel has already had a data logger implanted (a device that was surgically implanted and measures body temperature at a regular interval) or is wearing a light logger collar (like what Kate and I made the other day) also factors into the decision to bring them back to the lab or not.

If a squirrel has been caught before, it has an ear tag (sometimes two) with a colored wire attached to it. The colored wires indicate information at a glance, like the year the squirrel was tagged and if it has a data logger implanted or not. The ear tags each have a unique number that is recorded in a database, helping the researchers identify individual squirrels.

Squirrel ear tag
Close-up of ear tag on Arctic ground squirrel
##Squirrel in a bag

When we catch the squirrels, they don’t really have a desire to sit still in the cage while we attempt to read ear tags or determine gender. So, we use a mesh bag that allows us to handle the squirrel outside of the cage, then enables us to easily release the squirrel if we decide we don’t need to take it back to the lab. If I’m being honest, I have to admit that the first time I used the bag, I didn't cinch it closed tightly enough and the squirrel shimmied his way out just as soon as I got him in the bag. Luckily, my skills have improved with practice!

Squirrel handling bag
Kate Wilsterman sets up a handling bag on a squirrel trap

Squirrel handling bag
Kate Wilsterman with an Arctic ground squirrel in a handling bag

Arcric ground squirrel in handling bag
Alicia Gillean weighing an Arctic ground squirrel in a handling bag

Watch this video to see Cory Williams demonstrate how the squirrel handling bag works.

Toolik Field Station
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