Many raptors are scavengers as well as predators. Golden eagles, for instance, derive a significant portion of their winter diet from scavenging livestock and ungulate carcasses. Many buteos will scavenge under similar circumstances and there are records of scavenging by individuals of many raptor taxa. The literature for common black hawks (Buteogallus anthracinus) records a case history of a black hawk dying from an automobile strike while feeding on roadkill in Minnesota -- a very lost bird that must have gotten hungry enough to feed on anything available in its predicament.
The exploitation of carcasses as food source makes these birds vulnerable to both bait carcasses put out to kill other predators (wolves, coyotes, etc.) as well as to death from feeding on the dead (poisoned) predators. And raptors are killed by secondary poisoning by feeding on poisoned granivores, such as ground squirrels and prairie dogs, etc. killed as pests. It is also true that raptors may see the death throws of a poisoned animal and attack and eat that animal and then become victimized by secondary poisoning. Sometimes the secondary poisoning does not kill the raptor outright, but weakens it to die from starvation or predation -- once I came home to find a live juvenile red-shouldered hawk that someone had left on my porch in a burlap bag, and I found out that the young hawk had eaten a poisoned rat at a school in the county in a situation where the instructions for use of the poison had been ignored, resulting in the blinding and not outright death of the hawk. The proper (and legal) use of some poisons reduces the risk of secondary poisoning, such as placing the poison down into the burrow of fossorial mammals where the animals normally die without emerging above ground where they will likely be scavenged. Raptor veterinarians and rehabbers regularly see this sort of thing. The Raptor Center at the University of Minnesota could probably be consulted on this as I know they have a lot of experience in treating poisoned raptors, which are often the victims of secondary poisoning. Stan Moore San Geronimo, CA [EMAIL PROTECTED] >From: The Shrew Shrine <[EMAIL PROTECTED]> >Reply-To: The Shrew Shrine <[EMAIL PROTECTED]> >To: [email protected] >Subject: Re: ECOLOGY Poisoning Secondary Raptors >Date: Mon, 25 Jun 2007 23:47:00 +0200 >Received: from listserv.umd.edu ([128.8.10.60]) by >bay0-mc9-f13.bay0.hotmail.com with Microsoft SMTPSVC(6.0.3790.2668); Mon, >25 Jun 2007 14:57:59 -0700 >Received: from listserv.umd.edu (IDENT:[EMAIL PROTECTED] >[128.8.10.60])by listserv.umd.edu (8.12.11.20060308/8.12.11) with ESMTP id >l5PKfGJI003777;Mon, 25 Jun 2007 17:57:58 -0400 (EDT) >X-Message-Info: >oG9qAjD2BNGArElZXneTQrB5XEFQiYAuUO9VLbr1cHZQZfrx5XZ3MhefOF4tOCoY >Precedence: list >List-Help: <http://listserv.umd.edu/cgi-bin/wa?LIST=ECOLOG-L>, ><mailto:[EMAIL PROTECTED] ECOLOG-L> >List-Unsubscribe: <mailto:[EMAIL PROTECTED]> >List-Subscribe: <mailto:[EMAIL PROTECTED]> >List-Owner: <mailto:[EMAIL PROTECTED]> >List-Archive: <http://listserv.umd.edu/cgi-bin/wa?LIST=ECOLOG-L> >Return-Path: [EMAIL PROTECTED] >X-OriginalArrivalTime: 25 Jun 2007 21:57:59.0909 (UTC) >FILETIME=[E546C150:01C7B773] > >Dear Wayne, > >The topic is interesting. - I believe that raptors go for live >animals (i.e. movoing). They are not scavengers. It depends, however, >wich poisons are involved. A poison can reduce the animal's >locomotorics and might therefore make it more susceptible to >predation. (?) > >I am not aware of any specific papers dealing with this. > >Werner > > > >Forum: > > > >Can anyone link me studies that confirm raptor poisonings from eating > >poisoned rodents? > > > >Thanks, > >WT > > >-- >Dr. Werner Haberl >Former Chair, Insectivore Specialist Group, IUCN >Hamburgerstrasse 11/17 >A-1050 Vienna, Austria >Phone & Fax: (+431) 941 13 13 >E-Mail: [EMAIL PROTECTED] > >The Shrew Shrine: <http://members.vienna.at/shrew> >or new: http://members.chello.at/natura >The Dormouse Hollow: http://www.glirarium.org/dormouse _________________________________________________________________ Make every IM count. Download Messenger and join the im Initiative now. Its free. http://im.live.com/messenger/im/home/?source=TAGHM_June07
