Response to Blakeman on voles

Pale Male with Carlyle in background - 8/28/06
Photo by Lincoln Karim

Ben Cacace, a Central Park birder and long-time hawkwatcher, writes:

Marie,

A simple question for Blakeman:

I would think taking out a little over a third of any population would be considered a little more than making "a dent in the always-expansive vole population". Are you saying that voles are only predated on by Red-tailed Hawks? You don't mention any other predators having an effect on the other two thirds of the vole population.




Margie Siegal writes:

Regarding hawk control of vole population:

In a square mile of a healthy ecosystem, there are various mid sized predators. There are hawks. There are owls. There are foxes (and probably feral cats) Each of these are a part of the control of the rodent population. If you kill off the hawks, you eliminate a major element (possibly ¼ to 1/3, roughly estimating Blakeman’s calculations) of the rodent control mechanism. Other predators may (or may not, if they are also under human pressure) fill the gap. An analogous situation occurs with deer in Western states. We have killed most of the predators of deer. The deer population has exploded, hunting is not controlling it, and deer are all over our highways, eating our rosebushes and sometimes starving to death.