Rat Poison a Danger to Birds
It is a fine line between getting rid of pesky rodents and in doing so, attributing to the deaths of birds of prey. Researchers have been working tirelessly to try and determine which bird species are more susceptible to the poison and which birds are affected immediately, as well as trying to find ways to curb the accessibility of poisoned rodents to birds of prey. Their studies have had some remarkable and disturbing results, showing that less poison than previously thought is enough to cause serious damage.
It has been an ongoing study to figure out exactly how much rat poison is fatal for birds, and it seems that it does not take much to cause major harm. For years it has been known that wildlife is exposed to rat poisons through affected rodents. As rats were becoming resistant to the old poison formulas, new ones were created, but these poisons also pose a great risk. To understand the risks, a group of scientists from Environment Canada, with Philippe Thomas leading, began researching the effect rat poison had on birds by analyzing the livers from dead red-tailed hawks and great horned owls that they had found across Canada. It was important to the group to try and determine an estimated mortality rate for the birds, the rats and the population. It seems that some poisons do not kill rats immediately. Rats are still able to function for several days after poisoning, but as the poison begins to take its toll, rats become disorientated and easier prey for birds such as the great horned owl and the red-tailed hawks.
While studying the great horned owls, it was found that they were at serious risk of being fatally effected by the secondary digestion of rat poisons. The owls that were analyzed showed a higher percentage of poison in their livers than the red-tailed hawks, and their livers showed the presence of bromadiolone and brodifacoum. Scientists speculate that this result could be due to the different feeding habits and dietary needs of the birds. The lethal poisons that are in question are SGARs, or Second-Generation Anticoagulant Rodenticides. While it is understood that rats are pests and should be controlled, the team has stressed the urgency of educating the public on how to use these poisons safely, to pose as minimum a threat to wildlife as possible.