Wednesday, May 25, 2011

Trapping Squirrels

We started trapping California ground squirrels (Spermophilis beecheyi) a couple of days ago. We are trapping squirrels so that we can mark their fur. This will help us ID individuals during natural observations and experiments. We need to ID individuals because we are interested in knowing if squirrels interact with snakes close to or far away from their home burrow, and knowing which squirrels are more likely to approach snakes. Is it just the squirrel mothers, or do adult males also harass snakes?

To trap the squirrels we set up wire traps baited with sunflower seeds outside of active burrows. Below are the procedural steps we take to dye-mark their fur:

1) Scare squirrel into bag and hold down:

2) Inject hind leg with ketamine

3) Insert metal ear tags into both ears

3) Paint ID number onto fur (using nyanzol dye)

4) Measure body parts (snout to anus, leg length, tail length)

5) Wait for it to regain consciousness (perfect time for photo ops)

Although 96 traps are set out, very few squirrels have been caught. It takes them a while to become comfortable with the traps, but after they realize they can get a free meal, it will be hard to get them out.


  1. How is the Nyanzol-D working out and using the ketamine on the pups?

  2. The Nyanzol has been working good except we tried to use it in the rain yesterday and it did not work out so well. When we caught a pup, we weren't sure how much ketamine to inject so it was a little scary. Luckily the little guy woke up in about an hour and a half.

  3. Hello Bree, where can Nyanzol be found and for how long you think it may be visible on squirrels?

  4. Hi Arturdus, we got the Nyanzol from a company called Greeneville Colorants ( The dye did not last very long, only a couple weeks. We ended up switching to Nice and Easy hair dye which seemed to work much better.

  5. Hi Bree,
    First of all, I'm a french Canadian and my English isn't very good!
    But I study in Technical in bioecology at cegep of La Pocatière. Next summer I'll do a project with squirrels and I'll use the Nyanzol-D. I wonder if this product take a time before operating like a dye to hair? Because, for my part, I'll not use an anesthetic, so I don't want that my squirrels licks their pelage and at the same time this product.
    And I wonder if you can send me an instruction manual or a wed site explaining how to use this product because the Greeneville Colorant compagny can't help me.
    Thank you and sorry for my English


  6. Those are the cutest squirrels and so precious! Traps can be easily used to get the animals that you want and some are very humane - including snake traps.When we were young, my Dad taught us how to make snake traps from soda bottles and it was pretty cool! Today, you can just order from Amazon, which is also effective and still very humane to catch some rattlers around the camp or around your home. See this site for more ideas on how to make a snake trap:

  7. Hi Bree,

    Do you have to do anything to the Nyanzol D before you use it? Add any ingredients or anything? And then you just painted it on?