Squirrel Walk! August 11th, 2012

You can’t be suspicious of a tree, or accuse a bird or a squirrel of subversion or challenge the ideology of a violet.

– Hal Borland (American author and journalist)

Kevin the intern here!

On Saturday, we gathered for a walk around the area north of Lake Merritt. Guest of honor and guide was Lila Talcott-Travis, Director of Yggdrasil Urban Wildlife Rescue (www.YUWR.org).  She’s been working with squirrels for nearly twenty years, and has specialized in rehabbing them for about twelve.

There was an impressive turnout! People were coming and going (as it was around lunchtime), but the crowd was as big as 40+ people at the start of the walk – a lot of people like squirrels!

Beginning of walk, photo by Constance Taylor

Lila started by talking about the various species that live in the Bay Area, which include the Western gray (Sciurus griseus), the Eastern gray (Sciurus carolinensis), the fox squirrel (Sciurus niger), and the California ground squirrel (Otospermophilus beecheyi). She talked about their different temperaments, specifically of the Eastern gray and fox squirrels. Eastern grays and fox squirrels often coexist within the same urban settings, but the eastern grays tend to have a bolder, more assertive attitude while the fox squirrels are typically less aggressive, so eastern grays tend to dominate in areas where both are present.  Western grays, although native to California, are rarely found in urban areas as they prefer heavily forested environments.

We found several squirrel nests (dreys) on our walk, and Lila explained how squirrels quickly construct them out of leaves, twigs and any soft material they can find including bits of yarn, feathers, and even underwear! Squirrels live in dreys year round and can have two kinds in the wild- dreys made of leaves, branches, and other found materials, and dreys in pre-formed knotholes in trees – though they have been known to take up residence inside attics, as well. They construct multiple nests and prefer the knotholes when a mother is pregnant or during winter. Constructed tree-top dreys have a heavily cushioned cavity that goes around and below the main body, similar to the inside of a tire; this construction provides protection from the elements.  Infant squirrels, born blind, stay inside the cavity until they can open their eyes about five weeks later.

Squirrel drey, photo from DKimages.com

The clump of leaves near the center of the picture is a squirrel nest, or “drey”. Photo by Constance Taylor

Here’s a closer shot of a drey. Photo by Jackie Dove

Upon reaching the topic of baby squirrels Lila pulled a baby squirrel out of her shirt, to everybody’s surprise. She explained that she was in the process of rehabilitating three young squirrels (one of which still hadn’t opened its eyes) and that they had to be fed every few hours, which was why she had brought them with her.  One was an Eastern gray, and two were fox squirrels to be delivered to a new foster home that day.  After some cooing and fawning from the participants, she showed us the coloration differences between the Eastern gray and fox squirrel- Eastern grays have white belly fur and white guard hairs (the longer hairs on the perimeter of their tail), while fox squirrels have orange fur and guard hairs.

Baby Eastern Grey squirrel- notice the white guard hairs on the perimeter of the tail.  Photo by Constance Taylor

Baby Fox squirrel- notice that the tail is orange!  Photo by Jackie Dove

Lila also talked about the rise of a new melanistic (black) subtype of squirrel rising from the Eastern grays, better suited to retaining heat and hiding in an urban environment.  It was an interesting example of animals in the process of adapting to better survive the changes we make to their environments.

She also talked about how fox squirrels are an evolutionary “dead end” – they show evidence of being at the end stages of their evolution. For example, they have reached maximum cranial capacity for their bodies – if their heads were any bigger, infants wouldn’t be able to fit through their mothers’ birth canals when being born. In fact, female fox squirrels who are brought in for rehab with pelvic injuries must be put down because if they were released into the wild and became pregnant (which is very likely), even the smallest amount of scar tissue in the pelvic area will prevent the baby from passing through the birth canal, resulting in a very painful death for the mother and her infants.

In our walk, Lila also talked to us about feeding the squirrels. We learned that foods many people feed squirrels, like peanuts (remember, they’re legumes, not nuts) and sunflower seeds, are of negligible nutritional value and should not be a major part of every squirrel’s balanced diet. Bread doesn’t pass through a squirrel’s digestive tract very well either. Walnuts, however, are good for the squirrels, and almonds are better.

A participant asked how rehabilitating and fostering infant squirrels to be released back into the wild compared with the raising of infant squirrels by the actual mother squirrels. “It doesn’t,” Lila responded. The human parents try as hard as they can to care for the squirrels and provide for their needs, even making sure to raise squirrels together so they can understand squirrel body language and don’t get too used to humans or other domesticated animals, but they can’t do everything for the squirrels. In the end, “the best parent for a squirrel is a squirrel,” to paraphrase Lila.

Lila with one of our special guests, photo by Corrine DeBra

At the end of our walk, the three most important things she wanted us to remember were:

  1. Don’t use rat poison!  It might kill some rats, but anything else could eat it (including squirrels).  In fact, the baby Eastern gray she was rehabilitating was found after its mother had been killed by rat poison, but not before nursing her babies after she had eaten it.  The rat poison was in her milk, and so the babies were also poisoned but fortunately were found before they died.   Rat poison works its way up the food chain, so any owl, coyote, bobcat, etc. that would have eaten the mother or the babies would have been poisoned as well.
  2. If you want to feed squirrels, feed them good food!  In-shell walnuts, almonds, and hazelnuts are best.  If you want the squirrel to eat it right then instead of running to bury it then coming back for more, crack the nuts open and feed them the pieces.  Raw, unsalted out-of-shell nuts are okay, but the shells help to keep their teeth conditioned.  Raisins and chocolate cause liver damage, and they can’t digest bread.
  3. It’s okay to feed wildlife if you do it in moderation and with the proper food.  It’s important to have encounters with and a connection to wildlife; and as long as you’re not hurting the animals with what you’re feeding them, it can be a great way to appreciate all the different fauna around us!
Adult fox squirrel, photo by Corrine DeBra

Other things we learned about squirrels:

  • Their name in Latin, Sciuridae, means “Shadow tail” because of their propensity of holding their tails over their bodies.
  • Eastern grays have been known to travel in great migrations across land and even bodies of water.  Across water they’ll either swim or climb aboard anything floating in water and use their tails as sails.
  • Squirrels can use their tails as parachutes to slow a fall.
  • It is believed that squirrels are responsible for planting a large percentage of the world’s forests… up to 80%!  This is from their caching behavior- they bury more nuts than they need for later food sources.  The nuts they don’t eat grow into trees!
  • They’re found on every continent except for Antarctica.
  • In addition to communication, squirrels use their tails as shields. If they approach something they are unsure of or something they perceive as threatening, they place their tail between them and it. If a predator grabs the tail, it will “deglove” and leave the predator with a mouthful of skin and hair.  Sadly, unlike lizard tails, the squirrel tail will never grow back and it’s left with a bony, bald spike that makes it more difficult to communicate, balance, and do all the things it once could have done with a full tail.  The bald bony part eventually falls off, leaving the squirrel with a significantly shorter tail.
  • Squirrels have full color vision and see a deeper blue/green spectrum than humans do.
  • Squirrels are actually unlikely to carry rabies; rabies is transmitted through saliva, and squirrels have very dry mouths. If you are bitten by a squirrel, it is very unlikely that you will get rabies unless it was quite obviously foaming at the mouth and acting weird.

Here’s an interesting video of a Douglas squirrel moving her babies. Fox squirrels and Eastern Grey squirrels move their babies in the same way, but this was the best video we found…

http://www.youtube.com/watch?v=tT_196B7OE8

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