It's one of the best things about fall and winter.
With the cold weather and bare trees,
your bird feeders become hubs of activity.
Ever notice how some birds sit at your
feeder and munch, while others flit back and
forth on an endless quest to ferry seeds away?
Chances are this is for one of three purposes:
fear of hawks, lack of the proper "tools,"
or planning for the lean winter ahead.
Small birds like the ones that visit feeders
are constantly obsessed with finding safety from predators.
If food is at a risky, exposed location,
such as a feeder, birds must remain vigilant,
continuously scanning their surroundings for threats.
Birds such as Finches and Grosbeaks,
with their seed crushing bills,
can eat and scan simultaneously,
looking down only briefly to grab another seed.
Birds that must look down and hammer at seeds
prefer to fly to a safer place with their food
instead of working on it in an area exposed to predators.
This is why you often see Chickadees flitting
back and forth from feeder to trees or shrubs
and back with their seeds.
Some foods - such as shelled seeds and nuts - might even require specialized methods to crack them open.
Blue Jays manage to wedge the seed between their toes.
Looking down to work on a seed is still risky
and you will often see Blue Jays quickly
scan their surroundings before hammering away.
But the most fascinating reason is “caching”- the behavior
of storing up food supplies in a safe place for later.
This is one of the main reasons you see birds fly off
with their food instead of eating at the feeder.
Lots of birds - and even mammals such as squirrels,
beavers, and bears - cache food for consumption
later on, during lean times.
Caching isn’t as easy as it might appear.
A bird must fly back and forth,
one or a few seeds at a time, over hundreds of trips.
They also have to make sure the caches aren’t stolen and remember where all the food is hidden
when hunger strikes.
Most common North American feeder birds
can have anywhere from hundreds to thousands of
separate caches scattered around their home ranges.
Many caching species have keen spatial memory,
and can remember precise locations using
visual cues like distance and direction from landmarks
such as rocks and vegetation.
In fact, birds such as Black-capped Chickadees increase
the size of the brain (in the area associated with memory)
as caching ramps up in the fall.
I'm not so sure that Scrub Jays have that capability.
I have almonds sprout up under my larger trees,
probably from the orchards a few blocks away!
Ravens and Scrub Jays also cache as
inconspicuously as possible.
Ravens cache food behind structures so that
other Ravens cannot see what they’re doing,
and Scrub Jays prefer shady locations,
making it harder for other Scrub Jays
to see what’s going on.
Hence under our trees.
Now if they could only remember where they put them!
