Wednesday, February 18, 2009

Squirrel Strategies


A day without Nature is like . . . well, there is no such thing as a day without Nature.  Our nature event today was snow.  Not a lot. Yet. But soft and wet, clinging to every twig.  Pretty.  Especially from inside looking out.  Like the creatures of the forest, I stayed snug in my den today, happy to have a cache of food so I didn't need to go out.

I was wondering how squirrels find their acorns buried under all this snow.  So I turned to Hannah Holmes's Suburban Safari, which has a fascinating chapter about the nut-burying habits of American tree squirrels.  According to the squirrel experts she cites, they use both memory and smell, and they don't lose all that many.  But the truly amazing thing about squirrels is that they know exactly which kind of acorns to bury and which kind to eat on the spot: they eat the acorns from white oak trees in the fall and bury ones from red oak trees for winter.   Why? White-oak acorns germinate the same autumn they fall from the tree, so if buried, they'd promptly sprout. By January, there'd be no nut left to find.  But red-oak acorns don't germinate until the following year, which makes them perfect for winter storage.  How can the squirrels tell the difference?  Apparently, a squirrel can smell if an acorn is preparing to sprout.  If given access only to white-oak acorns, the squirrel will bite out the embryo that causes the acorn to sprout, and bury the now-sterile nut.  Isn't Nature something?

Not that my backyard squirrels have to worry about any of this.  I'd sure hate to add up the cost of all the bags of birdseed they've gobbled up this winter.  And winter sure ain't over yet!

3 comments:

swamp4me said...

"Not a lot" eh? Down here that much snow would pretty much shut everything down! I had read that squirrels used smell and memory, but I didn't know about the acorn eat vs. bury strategy. Thanks for sharing the information.
Stay warm!

threecollie said...

I was reading the comments on my favorite blog, Pure Florida, and was amazed to find someone "local" commenting. Your blog is lovely and I am delighted to have discovered it in such a round about way.

Woodswalker said...

Welcome, welcome, swamp4me and threecollie! Thanks for stopping by. I've visited both your blogs and really enjoy them. Be sure to visit my friend "Nature Girl" at www.adknaturalist.blogspot.com. We're all of us nature girls with much delight to share.