Subject: Re: cats at the land fill
Date: Sep 25 10:33:47 1995
From: Dennis Paulson - dpaulson at ups.edu


Jan Vafa wrote:

"Hi, I would like to subscribe to your newsgroup, but can't seem to do it,
so I am attempting to send you a message without subscribing. Hope it
works. I am concerned with some of the comments I have heard bandied
about, regarding the elimination of the feral/abandoned cats at the
landfill. I guess my concern is that the "hole" that would be created by
their removal, could lead to larger problems. One person did note that
if the cats were removed, others would probably move in. I think the
problem with the current situation is that the cat population is not
stabilized. If the adult cats were to be trapped, tested,
spayed/neutered, and returned to the colony as non-breeders, the
population and territories would stabilize. I also know that many ground
dwelling mammals, ie rodents, love bird eggs and chicks. Rodents are cat
food, and most cats find rodents and reptiles easier to catch than
birds. I have an indoor/outdoor cat, and she is a bird watcher (teaser)
but the only things we have ever found evidence of her catching are
rodents, snakes, and lizards. She will sit on top of the cars in the
carport and stare at the swallows in their nests, but there is no way she
can get to them, though she has tried. I have seen a garter snake
slithering down a blackberry bramble slope, from a nest in the fork of a
tree, with a suspicious buldge in its middle. Life is a cycle, and we
need to work with the cycle, not try to stop it. By stabilizing the cat
population, the rodents and reptiles will be kept in check, and I firmly
believe that more birds will survive to adulthood with the cats presence,
than without it."

Jan, I take issue with what you wrote. I imagine some others may do so
too, and hopefully there will be more light than heat. Just the fact that
we called the previous discussion "The Dreaded Cat Thread" shows the
emotions involved. Cats shouldn't be "dreaded," they should be understood.
In fact, we *do* understand that cats, taken as a group, are quite
efficient predators. We understand that they eat a wide variety of small
animals, including birds. I have read enough and have had enough cats in
my yard to know that they can be very effective predators on small
passerine birds.

As all predators, cats can become specialists, choosing and being more
effective at capturing certain of the prey with which they come in contact.
Some of them are entirely bird specialists (I have a book on the biology
of the domestic cat that mentions this, can't think of the reference right
now). Cats in my yard (where there are no reptiles and no diurnal small
mammals) hunt entirely birds.

Jan, you obviously care about the cats and want to present an argument for
their presence. But you couldn't be more wrong when you write that their
presence actually enhances bird populations. Cats kill far more birds than
rodents could ever affect by their occasional eating of bird eggs. No
study that I have seen lists rodents as major predators of bird eggs.
Lemmings are abundant in some parts of the arctic, but I've seen no mention
that they prey upon the shorebird eggs that they encounter. And, again, I
question whether there is a large rodent population at the fill.

Your comment about garter snakes is even more misleading. Garter snakes
eat almost entirely invertebrates and "cold-blooded" vertebrates such as
fishes and amphibians. Other snakes are quite effective nest predators,
but none of those species occurs on Montlake Fill (where I think there are
no snakes at all).

There's no question that mice and snakes are easier to catch than birds,
but that just isn't relevant here. I take it that you live out in the
country, if your cat catches only rodents, snakes, and lizards. Believe
me, most city cats (which, of course live in a place where there *aren't*
many rodents, snakes, and lizards) are bird hunters.

Finally, you are not doing Mother Nature a favor by trying to shift the
blame away from cats to put it on rodents and reptiles. There are already
more people who like cats than snakes and rats, and the latter have enough
bad PR of their own without having to take a rap for the real culprit.

In cities, CATS are unquestionably the most important predators on small
birds; I can't imagine what else would qualify. I will be convinced this
is true at Montlake Fill unless someone shows me a dietary study that
indicates otherwise.

If you encourage a "resident" population of cats, there of course will be
regular turnover (feral cats don't live anywhere nearly as long as pet
ones), and someone will have to capture and neuter cats there every year
from now to eternity. If there are only 5-10 cats present, that's exactly
how many cats represent a threat to the small birds of the fill. Much
better not to have cats in what some of us consider a wildlife sanctuary.

Dennis Paulson, Director phone: (206) 756-3798
Slater Museum of Natural History fax: (206) 756-3352
University of Puget Sound e-mail: dpaulson at ups.edu
Tacoma, WA 98416