Rodent Poison and Wildlife

Discussion of: Rat poison and the threat to Wildlife
By The Royal Society for the Protection of Birds (RSPB).
England and Wales no. 207076, Scotland no. SC037654.

Written by Lisa McCabe

As a child I remember discovering my first mouse, and it was dying of rat poison; I heard him crying on the lawn. It soon became apparent to me that my dad was baiting the garage. Rodent problems are apparent in a lot of different situations, rural and urban settings are targets for the populations. One thing that people often forget to consider is that rodents are a large part of our ecosystem, and adding poisons to that lower level of the food chain upsets the entire circle.

This past summer I spent my time doing an internship with the Wildlife in Need Center of Wisconsin; where I had brought lots of wildlife as a child, including the mouse I found on the lawn. Sometime in late July a young turkey vulture was brought in for rehabilitation that was found sick on the side of the road. There were no apparent parasites, wounds, or obvious symptoms that led to anything in particular. Blood tests were run, and before the results were back the vulture had died. We later came to the conclusion that he had eaten a rodent that had eaten poison.

The problem arises when we see wildlife, domestic livestock, and pets dying from the toxic nature of these products. Scavenging birds are particularly at risk like the red kike, as they receive secondary poisoning from the rodents. Other birds of prey also consume the rodents like barn owls, buzzards, and kestrels; predatory mammals are seeing this same risk.

Rodents become resistant overtime to the toxins and are surviving and reproducing, leading to use of the second generation rodenticides which are even more lethal to wildlife. Trapping is still the best way to handle a small population of rodents, and it eliminates the possibility of secondary poisoning with wildlife.

The report gives many different methods of prevention of rodent problems, since once a rodent infestation occurs it will be much more difficult to control. One simple way of preventing this is to clean up food, spills, and debris that are close to buildings so the rodents won’t have an available food source directly next to shelter. Keeping food in rodent proof containers also helps, along with eliminating possible entrance ways. Any openings in the building should be covered with 6mm wire mesh to prevent young mice from entering. The dairy farm I work at uses barn cats and trapping as means of rodent control.

There are many other methods discussed such as attracting predators to control the populations. Online I’ve found multiple different products that use a natural repellant, and have found great results. One site recommended using peppermint oil and soak rags or cotton balls in it, and leaving them in areas where rodents are frequently active. Other methods include sprinkling pepper, cinnamon, and cayenne in those areas, as well as use of the many herbs that deter rodents. If you do plan to go ahead and use rodenticides for large infestations follow the instructions carefully, and use this report (listed at the link below) as a guide to preventing wildlife exposure.

Wildlife plays an important role in the ecosystem, as well as maintaining our own existence. Although one may see the impact as small, a domino effect is a preventable inevitability when using poisons. Please consider the alternative methods available if possible when considering rodent control.


http://www.naturalengland.org.uk/Images/ratpoison_tcm6-16130.pdf