Dead great-horned owl in park ate poisoned rodents

The Glen Park News received this today:



A Completely Different Kind of Neighborhood Watch in San Francisco!


WildCare accepted Great Horned Owl Patient #1709 on November 8, 2012. He was DOA, dead on arrival.

He was a neighborhood mascot of sorts, now gone, but not forgotten. He was found on a popular walking trail.

As WildCare tests all predator patients for evidence of rodenticide (rat poison) poisoning, we tested this owl on arrival. And, as has happened in the case of many animals admitted this year – 74% — this owl was found to show evidence of exposure to rat poisons.

Examined at WildCare and necropsied (autopsied) at/by the California Animal Health & Food Safety Laboratory System, his body was found to be reasonably nourished (he had part of a rodent in his stomach), but was otherwise internally toxic, diffusely discolored and badly hemorrhaged throughout. He had died of “presumptive AR intoxication,” anticoagulant rodenticide poisoning. That meant that he had eaten poisoned rodents. Great Horned Owls consume 10% of their body weight every day, equal to approximately five medium rodents. A Great Horned Owl family with babies will eat considerably more.

It is very sad to have lost this owl. The people who found Patient #1709 generously paid for the necropsy. They and their neighbors are particularly concerned about a pair of Great Horned Owls who live in the same neighborhood, and have watched them nest there every year for ten years. They are worried that deceased Patient #1709 may have been one of that pair.

Commonly available rodenticides are consumed by rodents, the basic food source for a number of different predators all the way up the food chain. These poisons kill by making whatever animal eats them bleed to death internally – slowly and painfully. While the poisoned animals – targeted or not – are still alive, they can be consumed by other predators. It is a terrifying prospect; to kill many animals while targeting only one.

For the purpose of this release we include not only San Francisco media, but also the specific neighborhoods of Glen Park (where Great Horned Owl Patient #1709 was found), West Portal, Diamond Heights and Noe Valley to help them protect the remaining owls – and any other animals that could eat poisoned rodents there.

It is often a surprise to discover what humans categorize as wildlife in distinctly urban neighborhoods, but they have found a way to live with us. We need to find better ways to live well with wildlife.

WildCare Solutions is a program that can help with this kind of problem, as well as with nuisance wildlife, contact us at 415.453.1000, ext.23; WildCare Solutions at 415.456.7283 (456-SAVE), or

Great Horned Owls (Bubo virginianus) are common but strongly territorial, and therefore thinly spread. They are large birds, and measure approximately 18-25” in length, with a 4 ½’ wingspan. They tolerate a wide range of habitats, including some surprisingly urban settings. They are most active at dusk and after dark, hunting small animals, including rodents, rabbits, hare and small-to-medium-sized birds. The favorite prey of Great Horned Owls is skunks! They are the owls most often associated with their call, which is a familiar series of hoots. They are the most widely distributed owl species in the Americas. They nest early in the season, usually producing eggs some time between January and March.

WildCare leads the way in showing Bay Area people how to live well with wildlife through a complete cycle of respectful, practical and humane programs in wildlife treatment and environmental education.

Each year WildCare treats as many as 4,000 ill, injured or orphaned wild animals of  200 different species in our wildlife rehabilitation hospital, teaches more than 40,000 Bay Area child and adult participants in our environmental education programs, assists residents and businesses with wildlife dilemmas with our Wildlife Solutions service, and answers thousands of telephone calls concerning human/wildlife interaction on our Living with Wildlife Hotline – 415.456.SAVE.


76 Albert Park Lane   San Rafael, CA 94901




Filed under Uncategorized

5 responses to “Dead great-horned owl in park ate poisoned rodents

  1. Megan

    Very saddened to hear such an amazing creature left this world in such pain. FYI: PEPPERMINT OIL CAN BE USED TO DETER RODENTS.

  2. Thanks for posting this. A lot of people wanted to know about the necropsy results. It’s unfortunate that rodenticides are still being used in our city – the collateral damage is terrible.

  3. Dawn

    Thank you for this information. Do you know if pesticide companies in SF are aware of the problem?
    As a life-time Glen Park resident, I appreciate our neighborhood: the alleys, parks, trees and animals (well, an exception might be to the cute migrant squirrels who now yearly invade my walnut tree, depriving the raccoons of their harvest). None the less, they all give “a bit of country” to our City neighborhood..
    Thanks again for keeping us informed.

  4. Ted Edwards, Glen Park

    Does anybody know what effect the pesticides and herbicides that are sprayed in the canyon are having on wildlife or even human life? It seems like every other month there is a warning sign about spraying, plus there is illegal spraying that takes places as well. The chemicals being used in our parks are documented to kill endangered butterflies, which can only mean they do not discriminate against non threatened species. This article by a respected environmental reporter does not lie:

  5. Pingback: Save the Owls: Why You Should Not Use Rat Poison in Bernal Heights | Bernalwood

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