This was posted in response to a suggestion of introducing Mute Swans to
combat Canada Goose populations, as one person said that all the geese left
a water body where a pair of swans was introduced. Others responded with
evidence that swans had no effect on goose populations. The subject should
be of interest in our area.

I love the part about feeding poor people, something I've advocated for
years for "pest" animal populations.

>Date: Tue, 5 Nov 1996 09:09:54 -0600
>From: Rick Blom <rblom at blazie.com>
>Subject: MUTE SWANS/CANADA GEESE
>To: Multiple recipients of list ORNITH-L <ORNITH-L at UAFSYSB.UARK.EDU>
>
> Jim Greaves suggested that it was a mistake to introduce a
>non-native species (Mute Swan) to deter a native species (Canada Goose). He
>is right on principle but the specifics in this case are not as expected.
> Canada Geese are introduced breeders throughout much of the eastern
>United States. They are not native as breeding birds and the population has
>exploded. They are now considered a serious pest in many areas. In St.
>Paul, Minnesota, using a grant from the U.S. Fish & Wildlife Service, they
>are culling large numbers each year and using them to feed the poor. In
>some other areas, late summer hunting seasons have been opened in an
>attempt to reduce the population. So far it has had little or no impact.
> While Mute Swans are known to be aggressive and will exclude geese
>from some small ponds, they have been seen sharing larger ponds and
>reservoirs. I am not aware of any studies describing under what conditions
>swans will exclude geese. I assume that patch size, numbers of birds,
>season, and other factors are involved. In any case, introducing Mute Swans
>in the hope of limiting geese is not likely to be well received. Most
>states in the East with Mute Swan populations would like to reduce or get
>rid of them. Swans are destructive in several ways, limiting native
>waterfowl such as Black Ducks. Efforts to reduce swan populations through
>culling have met strong, uninformed, public resistence. It is nearly
>inconceivable that any state would permit the introduction of additional
>swans.
>
>Rick Blom
>rblom at blazie.com
>Bel Air, Maryland

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