Do Grey Squirrels Kill Red Squirrels?

Since the introduction of grey squirrels in the UK, our red squirrel population has been declining. Is this due to grey squirrels killing red squirrels, or something else?

Grey squirrels don’t actively hunt and kill red squirrels. However, the presence of grey squirrels causes a threat to red squirrels as they spread para poxvirus which is fatal.

Do Grey Squirrels Eat Red Squirrels?

Grey squirrels do not fight red squirrels, not for sport nor their meat. Whilst many species of squirrels are omnivorous, meaning they eat both plant and animal matter, they will usually only eat insects as their source of meat, and they do not eat other species of squirrels.

Do Grey Squirrels Attack Red Squirrels?

There are certain areas where both grey and red squirrels can co-habituate.

That being said, when grey squirrels come into areas with high red squirrel populations, the red squirrel numbers rapidly decrease. However, researchers have found that this does not appear to be due to negative interactions between the two species such as fighting.

So, the reason for the red squirrel decline does not appear to be due to random attacks from grey squirrels.

Do Red Squirrels Attack Grey Squirrels?

A two-way street has been paved between these two species of squirrels. Grey squirrels will not attack red squirrels and likewise, red squirrels don’t attack grey squirrels.

In fact, red squirrels appear to be much more timid in nature than grey squirrels. This includes both interacting with humans and other species of squirrels.

Do Grey Squirrels Pose a Threat to Red Squirrels?

Whilst we have established that there is no animosity between the two species, we have still not looked at the reason for the decline of red squirrels after the introduction of grey squirrels.

Below are a couple of the major reasons why the presence of grey squirrels has caused such a big threat and decline in the number of endangered red squirrels.

Para Poxvirus

Grey Squirrels have a strain of a para poxvirus disease. This is carried by a large number of grey squirrel individuals and it does not appear to affect their health.

However, they can pass this disease onto red squirrels, and it affects their health severely. This disease can sadly kill red squirrels and appears to be a major factor in the decreasing number of individuals.

Food Resources

This may not surprise you, but grey and red squirrels have a lot of overlapping dietary components.

Grey squirrels are a lot greedier and tend to eat more than red squirrel, so, when they come into areas of red squirrel habitats, they will eat a majority of the food required to sustain the population of red squirrels in the area.

As well as this, a decrease in food resources and an increase in pressure can cause problems for breeding red squirrels and often makes producing offspring a more difficult endeavour.

So, whilst grey squirrels do not directly attack or kill red squirrels, they are causing a decline in the population of red squirrels.

Whether it is via disease or a lack of resources, there is no denying that the presence of grey squirrels means the decline of red squirrels.

How Can You Help Red Squirrels

Many UK conservation efforts are beginning to focus on helping native red squirrels to survive in these hard times. However, looking at the ways in which we can help red squirrels often brings up some ethical debates.

One major aspect of helping red squirrels looks into controlling the population of grey Squirrels. This often means culling individuals of the species to keep the numbers lower. This is an ethical debate amongst many animal lovers.

But there are other ways to protect red squirrels.

Reintroduction programmes have become popular and it involves releasing red squirrels into areas which they once used to inhabit. They are then monitored to see if the reintroduction is successful and can be applied to further areas.

As well as grey squirrels, red squirrels are declining because of habitat loss. The development of more urban areas means fewer homes and less food for the red squirrels.

Conserving natural areas of land helps to protect homes and resources for future generations of squirrels.


To summarise, grey squirrels do not aggressively attack or kill red squirrels.

The presence of grey squirrels causes a threat to red squirrels as they spread para poxvirus which is fatal to red squirrels and they also decrease the number of resources for the individuals.

A decrease in the amount of food also leads to a decrease in the breeding success levels of red squirrels.

To help red squirrels, conservationists are trying to focus on reintroduction programmes and preservations of natural habitats for the red squirrels.

2 thoughts on “Do Grey Squirrels Kill Red Squirrels?”

  1. I just watched a fox squirrel kill and carry away a red squirrel
    They had it in its mouth the red squirrel was dead so much for your findings


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