We’ve just heard back about the results of the necropsy on the barn owl found dead
innear Glen Canyon. As suspected, it died of consuming rodents poisoned with rat poison. This is the letter we received.
Edited to Add: If you would like to spread the word to people not to use rodenticides, we have a flyer/ poster you could use. It’s here as a PDF: Avoid rat poison to save owls
The dead Barn Owl we found and took to WildCare for rodenticide testing, Patient #1754, was found, indeed, to have died of rat poisoning.
Many people don’t know that when a hawk or owl or other predator eats a poisoned rodent, that animal gets poisoned too. Please STOP using rat poisons (rodenticides)! These poisons are killing the very animals, like this Barn Owl, that naturally control rodents.
The Barn Owl was found to be internally toxic, diffusely discolored and badly hemorrhaged throughout. There was evidence of a heavy load of the rodenticide brodifacoum in her system — enough to kill her.
Shockingly, over 86% of tested WildCare patients show evidence of exposure to rat poisons! These animals are eating poisoned rodents and carrying varying loads of toxic poison in their systems as a result. Rat poison used by residents of San Francisco is having dangerous and detrimental effects on the wildlife of our area. A Great Horned Owl was found dead last year due to the same rat poisoning.
Rat poisons kill by making whatever animal eats them bleed to death internally – slowly and painfully. While the poisoned rats or mice are still alive, they (and their deadly load of poison) can be consumed by other predators including cats and dogs. Rodents are the basic food source for a number of different predators all the way up the food chain. It is a terrifying prospect; to kill many animals while targeting only one. We need to find better ways to live well with wildlife.
If you need help with any wildlife issues, please contact WildCare Solutions at 415.456.7283 (456-SAVE), or http://www.wildcarebayarea.org/wildlifesolutions.
Barn Owls are one of the most common owl species in the country, but seeing one, especially in the City, is always a treat. These silent nocturnal hunters often appear completely white against the night sky as they glide over open spaces in search of rodent prey. A family of Barn Owls can eat over 3,000 rodents in a single 4-month breeding season, which makes them a magnificent source of rodent pest control, but also one of the most common victims of secondary rodenticide poisoning. Barn Owls nest early in the season, usually producing eggs sometime between January and March.
A special thanks to everyone who made a contribution to the testing, especially to the San Francisco Forest Alliance for their substantial donation.
Thank you for taking the initiative in finding out what killed her. It’s a first step in spreading the word to save other owls.