In August 2020, a news article titled “Rats in the City of Castlegar” expressed concern towards the recent reports of rats in Castlegar, specifically the Black and Norway rat.
British Columbia is renown for its wide variety of wildlife species. However, not all are native to the province and those non-natives can cause harm to the environment, economy, agriculture, and private property. Invasive rodents are problematic because they have numerous characteristics that make them effective invaders that can quickly establish in an area.
Rats are prolific breeders. A pair of rats have the potential, in theory, to produce over 900 offspring within a single year. This kind of population growth, left unchecked, can get out of hand quickly. The worldwide loss of human food due to rats, both standing crops and stored food, has been well documented. Additionally, rats transmit diseases to humans, companion animals, and livestock.
According to the Centers for Disease Control and Prevention, rats can transmit viral and bacterial infections such as Hemorrhagic Fever, Leptospirosis, and Salmonellosis. These diseases are spread when food or water has been contaminated by rat feces. As we can see, rats are bad news and need to be managed to reduce their negative impacts.
Before you reach for a box of rat poison, a warning. Rat poison will kill all rodents. Rats are bad, but not all rodents are bad. Other rodents are important for seed dispersal, pollination, energy/nutrient cycling, and as a food source for many different predators.
Poison bait isn’t selective. The bait is made to smell like food and attract animals. If a non-target animal like a cat eats the bait, dead. Also, when the rat or a non-target animal dies from the poison and is then preyed on by a predator, that poison moves up a trophic level and another animal is killed, but not directly. Unless you can guarantee no one else has access to the poison, exposing animals to poisoned bait and poisoned prey is how rat poison becomes a poor option.
If poison isn’t a good option, what is a homeowner to do? There are some non-toxic alternatives such as snap traps. If you plan on trying this option, ensure that you get the right size of trap. Traps designed for rats are strong and should be set carefully. They should be placed somewhere that is inaccessible by pets, wildlife, and children.
If you don’t have rats in your area, there a few things one can do to keep it that way. Management of attractants can reduce the likelihood that they will take up residence in your area. Keep all garbage stored in secure containers, rodent proof your composter, clean up fallen fruits and nuts, and feed your pets indoors.
Protecting ourselves and the environment from the destruction brought on by invasive rats is crucial. The hope of this article is to convince you that although this new threat to the Kootenays requires intervention, it needs to be done in an environmentally appropriate and safe way.
Layton Baumbrough and Jackson Rooper are students of the Recreation, Fish & Wildlife program at Selkirk College in Castlegar.