When we asked the question about control of rats who were attracted to
the grain in the dove cote, Alan Richards put our query on Tweeters List Server.
Then someone on Tweeters put it out on the Wildlife Rehabilitators' List. This
process works wonderfully well! We want to share a composite of the responses,
and please feel free to pass this information on.
Anyone who puts out pet food, bird seed, food scraps in the compost, worm
box food, or just leaves picnic scraps behind, is luring large and small rodents
to the garden. There are good public health concerns here, as well as concerns
about domesticated animals in your care and wild birds you attract to your
garden. Rats eat eggs and nestlings, they will kill and eat birds and small
pets. Rats can go through the tiniest of openings, can enlarge small holes to
gain entrances into bird nesting boxes, your worm box, your doghouse, your own
house!

It seems so easy to put an inviting little feeder of D-con in the bushes
by the compost, or behind the dovecote. But then one gets to worrying -- what
about non-target animals eating this stuff? What about birds that eat the
poisoned rodents? What are the "secondary" risks?

D-con and other anticoagulants can definitely cause secondary poisoning
of birds of prey, cats, anything that might catch the rodents. since D-con
doesn't kill the rodents outright, there is plenty of time for them to stumble
around being a perfect target for any predators.

The newer anticoagulant rodenticides are far more toxic than the older
variety like Warfarin. It doesn't take much to cause fatal hemorrhaging.
Secondary poisoning of hawks and owls with anticoagulants appears to be a
growing problem. The Hudson valley Raptor Center reports several cases. It is
extremely important to document these cases, and to educate the public about
the continuing threat of poisons in the environment. Our documentation can help
strengthen restrictions on the use of unnecessarily hazardous pesticides.

The rat poison products contain substances like Diphacinone, Brodifacoum
and Bromadiolone and are sold under the names of Havoc, Talon, Volid and others.
Alternatives to D-con include Rampage, which comes as coated grain. Its active
ingredient is vitamin D3 which causes hypercalcemia and death in rodents without
the problem of secondary hazards. The Research Nursery, U of Idaho, has had
good results with this product. Rampage can be purchased from Plant Natural
(formerly Bozeman Bio-Tech), phone 406-587-5891, email ecostore at mcn.net; website
http://www.planetnatural.com.
Ward Stone, New York State's Wildlife Pathologist is an excellent source
of help and information. He can be reached at the wildlife Pathology Lab in
Delmar, New York at 518-439-8017.


Responders and Contacts:
Alan Richards, Clatsop Community College, alanr at orednet.org
Tweeters, tweeters at u.washington.edu
Dona Tracy, Hudson Valley Raptor Center, DTracyl at aol.com
Chris Maack, The Bird Treatment & Learning Center, Anchorage, AK,
73201.3124 at compuserve.com
Louise Shimmel, raptors at efn.org
Mark Pokras, DVM, Director, Tufts Wildlife Clinic, Westboro Rd, N Grafton MA
01536, 508-839-7918, fax: 508-839-7930
Kelly Cassidy UW, kelly at cqs.washington.edu
Kas Dumroese, Moscow Idaho, dumroese at uidaho.edu