Care need to reduce the rodenticide risk to non-targets

WITH the use of all pesticides, reading and following the product label is a strict requirement.

With rodenticides, however, it is also essential to complete an Environmental Risk Assessment (ERA). Think Wildlife’s Campaign for Responsible Rodenticide Use (CRRU) reported that routine monitoring from 2016 to 2021 found rodenticide traces present in nearly 90% of barn owls, demonstrating that more needs to be done to reduce the risk to all non-targets.

If all non-chemical preventative methods have failed, an ERA should be completed before applying rodenticides. This ERA should focus primarily on non-target species, those being animals which may consume any baits applied (known as primary poisoning) that are not rats and mice, and those which may consume poisoned rodents through predation or scavenging (known as secondary poisoning).

Which active ingredient to use is an important consideration as part of a planned approach to minimise and prevent both primary and secondary poisoning. Second Generation Anticoagulant Rodenticides (SGARs) have been termed ‘bioaccumulative’, simply meaning there can be a buildup of these rodenticides within the body, which occurs with repetitive feeding on the rodent bait or poisoned rodents. The non-anticoagulant active ingredient, cholecalciferol, which is used in Selontra, is neither bioaccumulative nor persistent in the environment.

It also goes without saying that all non-target species should be prevented from accessing the rodenticide bait, either by using a securable bait in a lockable bait box or by using the covered and protected approach, that is attaching bait to an object and covering with a sturdy item such as palettes, timber or tyres. Frequent searching for and disposing of dead rodents throughout the rodenticide treatment helps to prevent secondary poisoning, and ensuring all bait is removed following the treatment plan is essential.