Learning to Live with a Keystone Species!

If you look carefully, you can see the nest, which looks like a pile of brush but is carefully constructed.

Learning to live with a keystone species sometimes takes time!

The four foot pyramid-shaped pile of sticks and branches in the understory of a canopy of coastal live oak immediately caught my eye. I had never seen anything like it. Obviously, something had built this structure, yet to my uneducated eye, there was no indication as to what. The structure was located in the far upper reaches of our ranch. Everyday I passed this architectural marvel as I walked the ridge trail that traces that line where forest meets meadow and oak savanna. Each time I examined the area around the structure. Sometimes it appeared a coyote or some other animal had been digging into the side, but the identity of the animal creating this structure remained a mystery to me— until one day a friend’s scientist daughter identified it: This was a wood rat nest, the home of what is more commonly known as packrat.

I was fascinated and thought it a rare find until I found six such structures under the blackberry bushes along our remote driveway. The structures were about 20 feet apart, and again, there was no evidence of the rats, at least not in daylight hours when I could actually see them. I learned later that these structures can be as old as 70 years.

My real encounter happened much later. I was driving my new Prius to San Francisco when several warning lights came on at once. I pulled to the side and checked the owner’s manual: I needed to get to the nearest dealer immediately, which fortunately was at the next exit. I was flabbergasted to learn that my wiring had been chewed to the tune of $12,000 and in the space of the two evenings since my last servicing!

So rodents love Prius’ wiring, I was told. I live in the country and we have no garage. I wasn’t going to get rid of my car, so I was going to have to learn to live with this predator of electrical wiring.

My continuing efforts includ7 keeping the hood open so that the warm engine does not provide a haven for a cold rat. One winter evening I remembered that I had not opened the hood and rushed out to do this. When I lifted the hood, a wood rat sat on the motor rubbing her paws together to warm up!  Yes, I admit that I reluctantly set traps under the car and in it, as well as on the motor, and I caught several. I still carry electric traps on the floor of the car.

A friend told me that Irish Spring soap repels rodents. Wood rats eat it. My bars had gnaw marks all around the edges, and I had green soap crumbs all over my floor mats. Also, it almost fumigated me. I sprayed pepper spray under the car, under the hood, and even on the floor mats (I do not recommend the latter), and this worked some.

But I also soon began to find odd objects in my car, objects that I had never seen: a black plastic tube with loops along the side that had no apparent function, feathers, pens that were not mine. One day I opened the package compartment to find the odd plastic tube (yes, I had not thrown it out) and its loops were woven through by a feather. Later I learned these rats decorate their nests with anything that they consider appropriate. Was my car now synonymous to them with their nest?

I continue to suffer higher car maintenance bills due to having to have the air filter changed frequently and having to have regular rodent cleaning of the engine ($300 if no damage). But I feel better about it all now that I have also learned that these rats are a keystone species and an indicator species. Their presence reflects a healthy ecosystem and is critical to the continuance of health of the system. They are a food source for a variety of animals, including barn owls and great horned, hawks, coyotes, bobcats, mountain lions, and gopher and rattlesnakes. They are nocturnal, so we seldom see them, but it is said that if you shine a light into a tree over their nests at night, you will see shining red eyes (This is not something that I have done.) I actually look forward to what has happened since I was last in the car (you never know!) And perhaps most important, in this time when so much is dying and the climate and environment is so changed, it is a relief to see these survivors teaching me how to live with them, even if they sometimes cross the line!