URBAN YARDS CAN BE WILDLIFE FRIENDLY

During their first lab, I used to take the students in my vertebrate zoology class at the University of Puget Sound on a walk in the urban wilds. After we had walked a few blocks, I asked them to tell me why we weren't seeing any wildlife. When someone pointed out that we just saw a squirrel, I tell them that, sadly enough, this most obvious “wild” mammal isn’t native, nor are some of the “wild” birds we had seen.

But the answer is so obvious that eventually I always got the response I wanted:  “The habitat is so different from what it was.” They didn’t know the half of it! Not only do we cut down the trees, leaving a few token conifers, but we also wipe out the shrubs and herbs that make up the diverse understory of our forests. Each of those plant species has insects living on it, and all those insects disappear with their host plants. Guess the most important prey for our small wildlife species (amphibians, lizards, many birds and small mammals). That’s right, insects.

Don’t the cultivated plants we plant in the place of those we eliminate attract their own insects? Some of them do, but most aren’t native, and the insects that eat their leaves or pollinate their flowers may not occur here. And if they do appear, the typical response to them is a liberal application of pesticides. But it’s worse—most people favor evergreen plants such as rhododendrons and junipers that produce insect-deterring chemicals in their leaves and are thus relatively pest-free. Most evergreens fall in this category. And yes, I know honey bees aren't native, but they seem important in the pollination of many flowers, as our native bees have declined.

And the final habitat constraint most of us apply is instead of letting a great variety of (admittedly weedy) herbaceous plants become established in our yards, we literally mow ‘em down. If you watch your yard, you’ll see that the rare dandelions that go to seed are immediately attractive to any seed-eating birds in the neighborhood. But how many of us sanction this sacrilegious seed set? However we view them, seeds are the primary diet for many small birds and mammals.

So my answer is “Don’t do as your neighbors do.” If you’re like most of us and don’t live on a ten-acre lot with real habitat, do your best to simulate it. Remember two important food groups, seeds and insects. Plant native trees and shrubs, especially deciduous ones, which are more attractive to insects. Plant native flowers attractive to pollinating butterflies, bees and hummingbirds. Fruits are also important foods for many birds and mammals; plant plenty of fruiting trees and shrubs.

Don’t put any kind of biocides in your yard; save the aphids!

Leave a swatch of lawn unmown. Don’t rake up all the leaves and throw them away each fall; let them stay on at least part of your yard. Several of our wintering birds forage by turning over dead leaves, which shelter seeds from the summer before as well as a multitude of small arthropods and worms. Make a brush pile in one corner of the yard; songbirds love to shelter in it. Add a pond or fountain. You’ll be amazed at the wildlife habitat you’ve made.

Dennis Paulson

A BUSY RED SQUIRREL

On July 5, I spent some time watching a Red Squirrel (Tamiasciurus hudsonicus) processing Sitka Spruce (Picea sitchensis) cones at Manning Provincial Park, British Columbia. These small squirrels (around 250 g) are frenetically active and noisy, and watching them is much like watching birds go about their activities.

Two things impressed me about this behavior, persistence and proficiency. The forest floor, in a big grove of spruces, was literally covered with cones. Obviously it was a great cone year, not always the case in any given stand of conifers, and the squirrels were taking advantage of it. This particular squirrel would take only a few seconds to locate a cone on the ground, grab it in its mouth, and carry it up to one of its favored perches on a big fallen spruce trunk.

Fortunately, this was at eye level for me, right out in the open and allowing for continued photography. I don’t know why, but he (it was an obvious male) kept coming back to the exact spot to open the cones. And he did it again and again and again. That was the persistence part. But there is every reason for them to be persistent. When food is abundant, go for it.

Proficiency was also obvious. Each cone was held only for a few minutes, while the squirrel bit off each cone scale and swallowed the seed beneath it. I couldn’t determine whether the seeds were chewed or merely swallowed, as the process was so rapid. Sitka spruce seeds are relatively small (3 mm) conifer seeds, so perhaps they could be swallowed without chewing. However, they also have a “wing” that facilitates their dispersal by wind, so that must presumably be discarded.

In any case, each cone was reduced to its central axis in just a few minutes of manipulating it, the scales falling like confetti in front of the squirrel. It was then dropped, and invariably the squirrel gave its territorial chattering call for a few seconds. then it would hop off the log and pick up another cone and start again.

This squirrel processed cone after cone as I watched. Although Tamiasciurus squirrels are well known to store many of the seeds they harvest to feed on them over the winter, I saw no indication of any caching behavior. Red Squirrels cache bushels of green spruce cones in a single protected spot throughout the summer, and these cones become important when the ground is made inaccessible by deep snow.

When cached by certain verterbrates, some seeds that are stored are lost or forgotten, and they have the potential to sprout into new plants. In some cases (gray squirrels with oaks, nutcrackers with pines), the animal may be as important in the dispersal and reproduction of the plant as the plant is in the diet of the animal. This is not the case with Red Squirrels, which, because they store cones before they open, function entirely as seed predators and not as seed dispersers.

Closer to the coast of the Pacific Northwest, including all of Puget Sound country, it is the Douglas Squirrel (T. douglasii) that typically feeds on Sitka Spruce seeds. It is just as persistent and proficient.

Dennis Paulson