It is challenging to recognize red squirrels from grey as they look similar except for body colors. Red and grey squirrels have different origins and are distributed in other areas, which decreases the chances of mating.
Do Red Squirrels Mate with Grey Squirrels? Red squirrels do not mate with grey as they are sexually incompatible due to different species because red ones belong to Vulgaris, while grey has a species, carolinensis. Moreover, they appear distinct, having different features, behavior, mating signals, and habitats that make them less attractive to each other. Furthermore, grey squirrels pose a risk to the survival of red squirrels by transmitting deadly diseases.
In addition, the red ones live for almost 2 to 5 years, while the grey squirrels have a longer lifespan of nearly 6 to 10 years, which makes them incompatible.
Why do red squirrels not mate with grey squirrels?
Many factors account for the incompatibility between red and grey squirrels to mate, including physical and biological differences.
They look physically different, like their size, color, and the presence of fur on their bodies. Grey squirrels are larger as they are around 22cm to 30cm in height and weigh almost 420g to 580g.
In addition, they have a skull-shaped structure and bushy tails as distinctive features. They appear in blond, grey, black, and even cinnamon color.
However, these red squirrels are smaller in size as they are only 17cm to 21cm, and their weight is around 260g to 320g. They are equal in size to chipmunks but half of the height of grey squirrels.
Their body color usually appears reddish brown or a slight variation is rarely seen, and they grow little hair tufts on their ears in cold weather.
They have a noticeable difference in their behaviors as grey squirrels are communal and prefer to live together by sharing their territories and food supplies.
However, red squirrels are completely territorial and react aggressively when they have foreign organisms of the same genus in their territory. They begin to chase until they make them move away.
These do not want to share their food and nest sites and make noise to show their aggression.
Therefore, their behavioral difference also makes them incompatible with mating as they cannot tolerate males or females of other species around them.
They belong to different species but have a common genus Sciurus. The species of the red one is Vulgaris, while the grey furry animal has a species carolinensis.
Mating is impossible between animals of different species, even if they belong to the same genus. Therefore, the sterile offspring produce as a result of breeding between organisms of unrelated species.
Moreover, you can consider them reproductively incompatible as every species is a distinct group of organisms.
These cannot raise the population of fertile offspring after mating with organisms of other species. Animals of the same species can only breed and combine their genetic material to maintain gene flow.
Pose survival threat
The grey squirrels are larger in size, but red squirrels are usually seen chasing them due to their aggressive behavior.
They cannot tolerate the entry of foreign animals into their territory and fight to the death when one of them tries to get inside to take their food.
In addition, those having grey bodies are more robust in their actions and consume seeds. Therefore, they can efficiently consume and digest seeds with a higher tannins content.
So, the red squirrels have to find another location to find a good source of food; otherwise, they would die due to the unavailability of food.
Furthermore, they transfer deadly germs that can kill the red squirrels and threaten their survival, and are responsible for the decline in their population.
There are rare chances of direct contact as they occupy different areas, even in the same habitat. You can find grey squirrels in the urban areas as they prefer to live in forests having deciduous trees.
However, the red ones prefer to live far from the urban environment and dominate in the remote forests with coniferous trees.
So, you can only see grey furry animals in the backyard, as red ones are mainly found in remote areas. This decreases the chances of their mating as they live in different habitats.
Different mating calls
They have distinct calls to signal partners for mating or inform their nest mates about the possible threat of attack from predators.
These calls help identify and interpret their behaviors that they are interested in raising the population or getting aggressive against intruders.
Red squirrels make loud noises compared to grey ones as they scream for the survival of their territory.
However, both of them have different mating calls that are difficult to be understood by animals of other species.
How do squirrels mate with each other?
A female squirrel has the potential to mate with multiple males, and males can mate with numerous females, which indicates competition among them.
Many males begin to chase her to get a chance to breed and show aggressive behavior toward each other.
They enter a female territory, and a dominant male makes anti-predator calls for a few minutes after mating. It gives an alarm signal to other males to leave, and they will hide in a safe place.
After successful mating, the incubation period starts that lasts for 35 to 45 days in different species. So, the males have to compete to mate with females by showing dominant behavior.
Why are grey squirrels a threat to red squirrels?
Grey squirrels are a threat to red squirrels as they are large and can quickly seize them. Moreover, they can transmit deadly diseases leading to the death of red furry animals.
They carry a virus named squirrel pox, which is deadly for the red ones and wipes out their population quickly.
Moreover, they can also transmit parapoxvirus that can threaten the survival of red squirrels.
These are declared endangered species in areas of excessive deforestation and have a large population of grey squirrels.
They also consume green acorns, the food source for red ones, and destroy the fields entirely before they can get nutrition from them.
However, they are aggressive and do not allow grey squirrels to enter their territory to ensure survival.