Wednesday, February 24, 2010

Trees and Invasive Critters: The Importance of Raptors

I have recently had one of my pictures published in the Hills Conservation Network News...Below is the article with photo and Here is a link to the entire Hills Conservation Network Newsletter February 2010 edition...


The article “Raptor Perches Set to Control Squirrel Invaders” in the January 4, 2010 SF Chronicle brought back memories of the 1991 Berkeley-Oakland Hills Fire−and a lesson learned.  According to the article, Contra Costa County has erected 20 wooden perches to attract raptors that might once have perched in tall trees.

Without tall trees, the raptors (owls, hawks, falcons, and eagles) have flown away. Without the raptors that once dined on them, the ground squirrel population has multiplied in the meadows and along the ridges of Concord and Walnut Creek. They steal fruit from fruit trees, dig up lawns, and even (if one can believe the article) invade homes and schools. (And this army of thieves and rascals is made up of invasive natives--California ground squirrels!) 
Raptor perch installed in a meadow at Lime Ridge Open Space in the Mt. Diablo valley.
Photo courtesy of SmokeysMountain.blogspot.com.


California ground squirrel in front of its burrow (above left). Photo by Howard Cheng.

One lesson we learned from the 1991 fire was that once the trees were gone, the raptors disappeared as well. Many of us can remember seeing—not squirrels—but thousands of rats, mice, and voles infesting our hills. At night when we drove up the road, we could see those little and not-so-little critters diving into holes for safety as our car lights lit up ash-covered slopes.

Rodents (not ground squirrels) infested our homes, even as we rebuilt them. We knew that they carry disease, and they ruined the very ground we rebuilt on by creating tunnels. My wife and I were so concerned that we had professionals come and evaluate what we could do about the rodents of every size and shape that had taken over our property.


Every creature has a right to live--and competition for survival will keep most populations at a reasonable number. But this was too much. The trees were gone. The raptors were gone. Even the cats that used to make the rodents feel unwelcome were gone.


The professional evaluation showed that, after the ’91 fire, our land had over 10,000 rodents living on and under the ground. Luckily, we were able to pour a cement base under our home that eliminated the rodent problem until the trees, raptors, and cats returned to do their part again.

What does this have to do with the East Bay hills in 2010?  Some people in our hills are encouraging the removal of thousands of trees. They believe that grassland is a more desirable landscape. Why? Because grass is what covered these hills long ago. But with grass (and chaparral) come rodents—and snakes and other creatures that hide in low-lying vegetation.

When we moved to these hills they were covered with all kinds of tree species that made this neighborhood unique and beautiful. We don’t want trees replaced with grassland. The destruction of our trees will not only destroy this landscape that we enjoy. It will also change the ecosystem. 

The situation in Contra Costa County with people putting up wooden perches (made from dead trees) to attract raptors makes me realize how important it is to be careful about what we destroy in our environment. We are the interlopers here. Human ignorance and carelessness—not trees—are the cause of almost every ignition in these hills.

We have been blessed by being able to live in this community so close to nature. Let’s not destroy these trees that so many animals—and humans—depend on.
                                                            —Jerry Baer

No comments:

Post a Comment