Squirrels invading Screech Owl nesting boxes are like early stages of a forest fire: If you can fight them early enough, and persistently enough, you have a chance of putting them out.
One minute your Screech Owl is chilling in the box (left), and the next minute a squirrel has moved in with extreme prejudice.
You cannot let the squirrel have a chance to get attached to her new digs. You as the landlord have to evict the squatter asap.
In the eviction process, I have found that a nesting box video cam attached to your TV or DVR is half the battle.
Thanks to the mini-cam, and a three-pronged attack, I have had good success in evicting these bushy-tailed rodents.
(Note: No squirrels were injured in the making of this blog post.)
2. Once you have evicted the squirrel, check the owl-cam monitor. If the squirrel has brought in bedding material (see photo), remove it immediately (profanity optional).
3. Repeat Steps 1 and 2 until the squirrel gives up.
My theory, supported by a few years of January squirrel invasions is that the squirrel that is trying to nest in your owl box is in the family way, and she can't afford repeated evictions -- she'll soon find another nesting site.
Once you have a squirrel problem, you need to reduce the food source.
If you have bird feeders in your yard, you'll have to stop filling them for a couple of weeks, until the squirrel population wanes and peril has subsided.
Do you have successful squirrel eviction strategies? E-mail me at wrightjamesb (at) gmail.com.
I also highly recommend my new book, "The Screech Owl Companion," which devotes an entire chapter to squirrels and another chapter on how to build a squirrel-resistant owl bod designed by my co-author, Scott Weston.
You can order it here.