It’s common to see posts on social media imploring friends to care for lonely and sick pets. But what about the plight of our local wildlife that have become sick after eating smaller mammals (such as rodents) that has ingested rat poison?
The same agency officials charged with coordinating pet adoptions sometimes find wild animals in need of help. In Orange County, animal control departments know to call Dr. Scott Weldy, a local veterinarian who specializes in wild and exotic animal health. Dr. Weldy directs the medical care of these animals in partnership with agencies like the California Department of Fish and Wildlife, United States Geological Survey (USGS), and the Santa Ana Zoo under the guidance of strict federal and state laws to treat sick animals.
In September 2015, Dr. Weldy treated a young male bobcat suffering from mange, a skin mite infestation often found in predator animals that have ingested rat poison.
Dick Newell, a wildlife expert with local nonprofit OC Trackers who sometimes receives reports of wildlife sightings, stated that “On July 2, 2015, I began receiving reports of a sick bobcat’ in an Irvine neighborhood adjacent to a natural area.” Conversations with multiple people who had seen the cat suggested this male bobcat had mange. Months went by, and on September 8, 2015, Mr. Newell again received reports of an extremely sick male bobcat, assumed to be the same one due to proximity to former sightings.
Photo showing mange September 19, 2015
The 15-pound young adult male bobcat was captured soon after by local animal control and placed into the care of USGS, who gave him the name, BNX (or for convention, Binx). Dr. Weldy and colleagues were tasked with treating Binx for mange. Weldy’s team gave him a thorough exam, which included recording measurements and fitting Binx with a light lavender/pink ear tag to help identify him.
Anticoagulant Rodenticides Linked to Mange and Wildlife Poisoning
Bobcats (Lynx Rufus) are native to Southern California and continental North America, and have historical significance in Native American and early European folklore. These spotted felines have ‘bobbed’ tails. Adults can reach 20 pounds, and are sometimes mistaken for large house cats. Bobcats live mostly solitary, quiet lives, avoiding humans…spotting a bobcat is rare. However, these predators are essential for maintaining the balance to ensure the beauty and resilience of local wilderness parks.
In recent years, bobcats in southern California have been showing signs of health problems, especially mange – a disease caused by parasitic mites that burrow into the skin and debilitate the animal. Mange is associated with a weakened immune system; Researchers who have studied bobcats and coyotes throughout the state have found that animals with mange have often ingested certain types of rodenticides, a class of pest control chemicals commonly used to kill rodents in urban areas.
These poisons, sometimes referred to as super toxic poisons, superwarfarins or second generation anticoagulant rodenticides, are designed to disable the body’s blood clotting ability. The Center for Biological Diversity (CBD) states on their website that “Second-generation anticoagulants — including the compounds brodifacoum, bromadiolone, difethialone and difenacoum — are especially hazardous and persist for a long time in body tissues. These slow-acting poisons are often eaten for several days by rats and mice, causing the toxins to accumulate at many times the lethal dose in their tissues and poisoning predators that eat the weakened rodents.”
Predators such as bobcats, coyotes, owls, and other birds of prey suffer from mange, internal bleeding, a weakened immune system, dehydration, starvation, and eventually death. The CBD states the poisoning of more than 25 species throughout California has been documented.
Binx: Hope For the Future
Binx was released after many weeks under care, near his capture location in Irvine, and has since been spotted by local wildlife photographers, to the delight of wildlife enthusiasts. In some photos taken on New Year’s Eve in 2015 in an Irvine wetland, Binx looked robustly healthy, flashing his pink/lavender ear tag as he strutted across a boardwalk.
Erin Boydston, a research ecologist at USGS, notes that cases of bobcats that are treated and released are rare, and it’s helpful to have a chance to examine these cats to get a better picture of the issues they face in the wild. A bobcat with mange that is treated and released is a success story, since some animals with mange never recover.
The use of rodenticides is currently being challenged throughout the state and the nation. Effective 2014, the State of California banned direct-to-consumer sales of second generation anticoagulant rodenticides. However, licensed exterminators and farmers may still use the poisons. The EPA also banned retail sales of these second generation rodenticides in 2015, but continue to allow their use commercially.
Some advocates hope to see even stricter controls. Assemblymember Richard Blook (D-Santa Monica) will introduce AB 2596 in the spring of 2017, which would ban the use of second-generation as well as some first-generation rodenticides throughout the state.
Hopefully, Binx is still out there, healthy and robust. Predators like Binx are essential to keep our rodent population in check and our ecosystems in balance. Could he be the new Orange County mascot?
*Note to the public and photographers: Information about our wildlife and photos helps agencies manage wildlife and their habitats. Please report any sightings of a bobcats to OC Trackers via their online tool at: http://www.octrackers.com/bobcatsightings.htm.