Can a Bird Die From Eating a Poisoned Mouse?

by Derrick | Last Updated: April 24, 2022

Mice can be a grave problem in your home, garage, or yard, and if you reside on a farm, in your fields, or gardens. One of the most common methods people use to get rid of the mice is poisoning. Unfortunately, birds of prey find the carcasses quickly and feed on them.

A bird can die from eating a poisoned mouse. A single dose of rodenticide is enough to kill a mouse, but it takes a few days, during which the rodent may continue eating the poison. The mouse becomes increasingly weak, and if a bird preys on it, the predator ingests a lethal dose of the rodenticide.

Birds of prey and other predators provide natural rodent control services. However, rodenticides pose a danger to them, and without intervention, these animals will die from the poisons. This article will show you how rodenticides affect birds and give you alternative ways of safely eliminating mice.

How Birds Die From Eating Poisoned Mice

Many people try to solve mice problems by purchasing baits that contain brodifacoum as the active ingredient. This highly toxic chemical is an anticoagulant that causes death by internal bleeding. Anticoagulants thin the blood, and the animal slowly bleeds internally to death.

Mice Eat Lethal Doses Of Anticoagulants

First-generation anticoagulants take roughly seven days before the mouse dies because a lethal dose requires multiple feeding sessions. Second-generation rodenticides are more efficient and kill the rodents from internal bleeding within three days.

Many consumers prefer second-generation anticoagulants because they can kill a mouse with only one dose, but they do not kill mice immediately. The poisoned rodent can live and continue eating the poison for a few days. 

By the time it succumbs, the mouse could have enough poison in its system to kill a bird of prey.

Mice Can Travel a Short Distance Before Dying

Unfortunately, the mice can get out of your garage or yard and travel a short distance before dying. 

As they move, the weak rodents become easy targets for birds of prey like hawks and owls. The mice become lethargic and cannot move as fast as healthy ones, and the weaklings are the ones that the birds, especially the owls, take. 

Birds Suffer From Secondary Poisoning

Even after the mice die, the carcasses contain lethal levels of anticoagulant rodenticides. The birds then suffer from secondary poisoning, where a predator ingests poison from eating a poisoned rodent. 

Feeding on the poisoned mice concentrates the anticoagulants in the birds, and they die from internal bleeding.

It’s Impossible To Treat Poisoned Birds

It is challenging at best to treat poisoning in birds. 

By the time the birds show symptoms, treatment rarely works. Once the bird eats the poisoned mouse, the rodenticide takes at least six months for its body to eliminate all the toxins.

The poison affects the liver the most because one of the functions of the liver is to filter blood and rid it of toxins. Also, secondary injuries like cuts or lacerations become life-threatening because the blood is too thin to clot. 

There is no conclusive data on what constitutes a lethal dosage after a bird eats a poisoned mouse. 

Some Birds Live For Years After Being Poisoned

However, different bird species succumb to different dosage levels. The danger is more significant in species that feed on rodents more exclusively.

Birds of prey like owls that naturally feed on rodents can easily consume several poisoned mice . Furthermore, anticoagulant rodenticides do not break down rapidly, as some can remain in the organs and tissues for months or years. 

This delay makes the birds more vulnerable to a fatal dose of poison.

Is There a Safe Poison For Birds?

There is no safe poison for birds who eat poisoned mice. Secondary poisoning is becoming increasingly significant because new rodenticides are more potent than older ones, and the mice population is rising steadily. 

However, anticoagulant rodenticides top the list of chemicals with significant risks to all animal species.

The US Environmental Protection Agency (EPA) banned second-generation rodenticides from the consumer market. Only licensed exterminators can use them. While the ban helps minimize accidental ingestion by pets and humans, it doesn’t prevent birds from feeding on poisoned mice.

Alternatives to Mouse Poisons

If you are environmentally conscious, there are many easy, economical, and effective pest control methods. Let’s take a quick look at these alternatives.

Snap Traps

Snap traps are fast, efficient, and more humane than poisons that cause a slow, painful death. They also have the added benefit that birds will not die from eating the dead mouse. The main drawback of traps is that they can be challenging to set and might snap on your fingers. 

You also need to constantly check them, reset, rebait, and dispose of trapped mice. If you don’t like handling mice, you can use either of the two types of repeating traps

The first is a mechanical trap with a spring that you wind up. You can add bait or place it in a dark corner. When the mouse comes exploring and sets off the trigger, the paddle blade pushes the mouse inside, and the trap resets for the next rodent.

The second type is a metal box where you place a bait and close the lid. The trap has two doors through which the mouse can enter, and once inside, it cannot escape. The mouse dies of starvation

You then remove the carcass and replace the bait.

Integrated Pest Management Approach

This approach refers to the process of making your home or garden unfriendly and less attractive to rodents. 

You can:

  • Seal all potential wall and roof access points or cavities that mice might be using.
  • Ensure any excess pet food is not accessible.
  • Pick up fallen fruit.
  • Plant owl-friendly native trees to replace mice-friendly palms.
  • Tidy up all garden waste and block access routes to compost heaps.
  • Rodent proof your chicken pens and bird cages.
  • Put up nesting boxes for owls to nest.

Minimize Dependence on Poison Bait

Doing any of the following will help reduce over-reliance on poison baits:

  • Only put out poison baits when it is necessary.
  • Use first-generation rodenticides or other alternatives. Check for active ingredients such as Coumatetralyl, Chlorophacinone, Warfarin, or natural components like Sodium Chloride.
  • Avoid using second-generation anticoagulant rodenticides.

Take Away

Birds of prey are valuable in eradicating mice from homes, gardens, and yards. However, they are at risk of death if people continue using second-generation anticoagulant rodenticides. 

It is critical for anyone seeking pest control services to consider alternative approaches and save the birds from these poisons.

Of course, you can do what my dad did when I was little. You could drop each mouse into the woodstove while the fire is nice and hot. But I don’t recommend that if you’re sensitive to mice screeching.