By Mary Pringle for The Island Eye News
Many of us who live on barrier islands where houses are elevated have had the unfortunate experience of having rats get into our garage ceilings or house walls and do damage to water lines, electric wires, sheetrock, or ductwork. Sometimes they even die inside the walls and create an awful smell. An even bigger problem is that rat poisons can be a danger to other beneficial wildlife such as hawks, owls, bald eagles, vultures and nonvenomous rat snakes that die from eating poisoned rats. Though some may not be popular with people, these predators and scavengers have an important role to play in keeping our rodent population in check. Pets have also been known to eat poisoned rats. These poisons have had a dramatic effect on Kiawah Island’s bobcats which had a population of about 35. In recent years, because of the use of certain rat poisons, their numbers are down to about 10. This has led to an increase in the deer population and necessitated a deer management program because of problems such as disease-causing ticks. Kiawah has begun a Bobcat Guardian Program that includes residents working to preserve bobcat habitat using native plants and pest control providers who have discontinued the use of rat poisons. I have witnessed poison’s effects on wildlife when called to capture an adult bald eagle on a plantation near Huger, SC and again on Sullivan’s Island where neighbors witnessed a Red-tail hawk suffering from toxicity. Even though I was able to get them to a medical facility for treatment, the damage was so severe that both soon died. The neighbors on Sullivan’s said that someone on their block had been aggressively poisoning rats. An article in the winter 2021 issue of Audubon magazine by Chris Sweeney has well illustrated the effects of what they are calling “second-generation anticoagulants.” These are much stronger and kill more quickly than the earlier ones such as warfarin. The four very toxic ones include brodifacoum, bromadiolone, difenacoum and difethialone. No product with these on the label should be used. Although the EPA has made an effort to restrict these products, they have unfortunately become available through online sources including Amazon, Walmart.com, eBay, etc., and can be ordered by anyone. The pandemic has caused a spike in rat populations in some cities and caused an increase in orders of these products. According to Sweeney’s article, a problem with these very strong products is something called their “half-life” which means they can accumulate in the food chain with more birds tested with anticoagulants building up in their bodies. At the Tufts University Wildlife Clinic in 2019, 100% of 43 Red-tailed hawks tested positive for these poisons even if they did not all die because of them. What can we do here on our islands to get rid of rats without using rat poison? Here at my house, we have had good success using the old-fashioned “snap traps” baited with peanut butter to control rats. Then we bury them. Care must be taken, however, to place traps in an enclosed space where pets or children cannot accidentally spring them.
Mary Pringle is chairperson of the Isle of Palms Environmental Advisory Committee and holds permits from SCDNR for sea turtle nesting and rescue/stranding response.