Doubt about outdoor cats' impact on wild birds

A recent article in the Telluride Daily Planet expressed concern about the validity of studies that blame outdoor cats for bird predation. The column written by the Second Chance Humane Society said:

These days, there are studies on the Web that can support pretty much any position on any issue. Beware, though. These studies often lack validity and fail to rely on scientific method. A prime example, in our opinion, is the “Wisconsin Study”, a study by John S. Coleman and Stanley A. Temple, that argues that free-roaming cats pose a serious threat to bird populations. Of this 1992 study the authors later admitted that it was simply “guesswork” and did not rely actual data.

Despite the fact that the study was never published — thus sparing it from peer review or validation — it continues to form the basis of further work on the same issue. It also continues to be used by some conservation groups. In fact, SCHS received an e-mail from Steve Holmer, director of public relations for the American Bird Conservancy, in response to last week’s pet column. In his e-mail, Holmer cites Coleman and Temple’s work. His group proposes the banning and elimination of free-roaming cat colonies “through humane capture by animal care and control facilities.”

Conservation groups also use other studies, such as these two cited by Golden Gate Audubon Society and this published study conducted in Michigan.

The column also said:

We at SCHS believe that humans — and their lifestyles — are probably the worst culprits when it comes to decreases in bird populations. Second Chance proposes forming an allegiance with bird advocates like the American Bird Conservancy and working together toward the serious factors that are diminishing bird populations to a greater degree than cats do. And, with regard to whatever impact free-roaming cats might have on the bird populations, how about if bird advocates were to work with feral cat advocate groups toward humanely controlling the population of feral cats through a structured spay/neuter program? This would be, in our opinion, far more effective, and humane, than trying to eliminate these cats altogether.

SCHS also suggests that bird groups work with cat owners that allow their cats outside to make efforts to protect birds.

Second Chance encourages anyone looking to blame cats for declines in bird populations to look carefully at the research, and to consider that other elements besides outdoor cats might be more responsible.

What do you think of the validity of those suggestions?