How Scatter Hoarders Prepare for Winter

Dave Anderson, Chris Martin | August 22, 2019
Tags:
Wildlife

Winter's coming. Just ask a gray squirrel.

You may be familiar with hoarders (not the TV show, but same idea).  In nature, a hoarder will hide food in one place.  Everything it gathers will be stored in a single tree or den.  But for some animals one food cache isn't enough.  We call them scatter hoarders.

A "scatter hoarder" hides food in a bunch of different places within its territory.  The gray squirrel is a classic example, gathering acorns and burying them in trees or in the ground.  Not all squirrels are hoarders.  

Red squirrels are "larder hoarders."  If you've ever been walking through the woods and a red squirrel starts screaming at you, it's defending its one and only stash.  The same goes for chipmunks and white-footed mice who cache their food in a central larder which functions as their primary winter pantry.

The gray squirrel isn't alone in the practice of scatter hoarding.  Blue jays gathering autumn acorns in oak forests of central and southern NH and gray jays in spruce and fir forests of the White Mountains region spend their summers begging from hikers, filling their territories with as much granola, raisins and peanuts as they can gather.  They bring the bounty back into the forest and glue the food into the bark crevices of trees using saliva to stick the food to locations which will be above the deep winter snowpack.

 I know, who spits on their food?!  Well, the squirrels and jays do.  

Gray squirrels lick their acorns before burying them.  Since squirrels haven't quite mastered the science of cartography, tracking down food stashes in the winter can be challenging.  Their saliva acts as an olfactory signpost - they can smell the spit through the snow and frost.  The only problem is other squirrels may smell the cache and steal the food.  

At first glance, this may not seem like the best strategy but it does work, and gray squirrels aren't the only ones who have to deal with such theft.  A tufted titmouse will grab seeds from a feeder, fly off and stash it in a tree, only to have a red-breasted nuthatch come along and take those seeds.  So how is this behavior effective?

All of these scatter hoarders have hidden cache sites all over their territories; they don't put all their eggs - or seeds - in one basket.  

Sure, some of their food will be forgotten or stolen over the winter, but the goal is to have so much food they'll still have enough to get through the winter.  And as for the buried nuts that no one finds, they are planting the next forest! When those trees mature, they will provide food for future generations of larder hoarders and scatter hoarders.  Its an elegant seed-planting strategy from the perspective of forest regeneration.

Please pass the acorns.