A Eastern fox squirrel checks the surroundings before heading out.

There is something about a squirrel that makes me happy.  To me, they are just happy creatures.  Now I don’t have any empirical evidence showing squirrels are overall more happier than, say, rats.  And, like most rodents, they are pretty low down on the food chain so they live a life of vigilance.  But if you had to design a happy creature from scratch, chances are you’ll end up with something like a squirrel.  Adorable, energetic, bushy tail, bouncy run.

Use to handouts, this fellow at the park had little fear in approaching me.

In my neighborhood in LA, I see squirrels almost everyday – traversing the neighborhood via power lines, madly dashing across the street (in their very adorable sine-wave run), climbing up palm trees.  Sciuris niger, the Eastern fox squirrel, is a cosmopolitan fellow.  Found in most of the urban areas in California, fox squirrels can weigh up to 2.2 pounds, with a tail as long as 13 inches, the largest of the North American tree squirrels.  While their coloring is variable, those found in Los Angeles have a reddish brown coat speckled with grey.

Like many animals that thrive in urban settings, the fox squirrel is a generalist, adaptable to a wide range of environments and food.  Included in their diet are acorns, leaf buds, bird eggs, seeds, insects, bulbs and fungi.  In California their diet can include citrus fruits, strawberries, tomatoes, even eucalyptus seeds.  A co-worker of mine had a large avocado tree constantly being raided by squirrels.  I’m sure they eat the fruit from palm trees given how often I see them scampering up them.

Two adversaries face off at a chance meeting in the park.

Of course the fox squirrel’s main purpose is to drive dogs crazy.  I have one fellow that lives in the trees along the back of my property.  It gets around the neighborhood via the cable lines strung along the back of the property.  It’s hilarious to see my dog go crazy whenever the squirrel is out and about despite having no chance at getting it.  

Safe from dogs, cats and kids, squirrels take advantage of cable and phone lines to move around the city.

My dog Rocky tears off to the back fence.  Reaching the fence, he realizes the squirrel is now further above him, so he goes back up the slight incline in the yard, bringing him closer to the squirrel in elevation but still far out of reach.  All this is followed by frantic back and forth accompanied with barking, but after an initial pause the squirrel goes on with its tasks.

The fox squirrel provides a bit a wildness for us city dwellers.

While I enjoy having these wild critters around, the problem is the Eastern fox squirrel isn’t a native to California.  They are found throughout Eastern and Central United States, from the Gulf of Mexico to Southern Canada.  The first Eastern fox squirrels in California were released in San Francisco in the late 1800’s.  The population in Los Angeles came from captive squirrels at the Veteran’s Hospital in West Los Angeles that were either released or escaped around 1904.  Separate populations were also established in San Diego, Fresno, Sacramento and numerous other California cities.

Once free, the squirrels quickly expanded their range, spreading throughout cities and suburbs.  In Los Angeles, it is estimated the squirrels have expanded their range from 1.5 to 3.44 kilometers per year (roughly 1 – 2 miles per year).  Helping the process along are people who trapped pesky squirrels and released them in parks, golf courses, and natural areas.  Since fox squirrels are generalist and urban California is an irrigated wonderland, the squirrels are able to thrive.

A Western grey squirrel enjoying a little snack.  Photo by HomeinSalem from Wikimedia.

But we have another squirrel in California that is losing ground – the Western grey squirrel.  The largest native tree squirrel in California, the grey squirrel can also weigh up to 2.2 pounds but generally is slightly smaller on average than the fox squirrel.  But with the classic squirrel tail – big, bushy and held upright in a big S – they appear larger.  Unlike the fox squirrel, the Western grey squirrel has a more specific diet of tree nuts, mostly acorn and pine nuts.  This limited diet plays a big role in the expansion of the fox squirrel and the decline of grey squirrel’s population.

The fox squirrel is an animal that has adapted to the very unique ecosystem created by our urban areas.

But does that make the fox squirrel an invasive animal?  Or is it taking advantage of an opportunity created by human transformation of the ecosystem?  It is, generally speaking, hard for a species of animal or plant to become invasive in a healthy ecosystem.  A species is more likely to become invasive when humans disrupt the ecosystem.  Grey squirrels thrived on the wild oak and walnut trees that once flourished here.  Being more reclusive than fox squirrels, they find safety in denser brush and forest growth.  Much of the retreat of the grey squirrel would have happened anyways without the fox squirrels.

In writing about nature in the city, my focus has been on what remains of the natural environment – those pockets of wilderness surrounded by concrete or where the urban edge meets wild edge.  But urban areas themselves become unique environments where the original inhabitants either leave or mingle with introduced species, and they all find themselves adapting to seemingly uncaring human herds.  While cities may occupy a specific environmental region, it also creates a specific environment – one the Western grey squirrel is ill-suited for.

This fox squirrel is perched in some of the wild scrub found in Kenneth Hahn park.  

Retreat into the mountains that loom over Los Angeles, the grey squirrel reappears, happy in its own habitat.  But the fox squirrel is hardly seen.  In one of our larger urban parks, Griffith Park, both fox and grey squirrels share the park.  Perhaps that is because Griffith Park is a mix of manicured parks and wild scrub.  Near to me at the smaller Kenneth Hahn park, there are no grey squirrels.  Most of the fox squirrels I encounter are in the well maintained parts of the park, wide mowed lawns interspersed with mature sycamores and pines.  In the parts of the park that are a dense, wild mix of native and non-native plants, only occasionally do I come upon the fox squirrel.

The real test if the fox squirrel expansion will be fatal for the grey squirrel will play out in the next decade.  Their expansion has now covered most of urban and suburban California.  Once they reach the edge of the track homes will they continue to expand?  Will the grey squirrels be pushed further and further into the mountains till there is no place left for them?  And how do we respond to this?

Two fox squirrels check me out as I photograph them.

The Eastern fox squirrel is here to stay.  Within the bounds of our cities and their unique ecosystems, that may be okay.  But beyond, we owe it to the Western gray squirrel to make sure they too will have a home. 

Photographs by Alan Starbuck unless otherwise noted.