A question was raised as to whether feral cats in colonies become inbred. They might become inbred because we know that, when given the opportunity, domestic and feral cats engage in what humans might consider to be orgies! Feral and domestic cats are very good at procreation and my colleague Elisa described it as rape but in truth it’s not that because both females and males willingly engage in mating in colonies which might lead to close relatives mating causing inbreeding.
A study published in 2001 helps us ask the question as to whether there is inbreeding in feral cat colonies. The study is called Female Control of Paternity during Copulation: Inbreeding Avoidance in Feral Cats. The study was carried out by the Department of Biology, Faculty of Sciences, Kyushu University, Hakozaki, Fukuoka 812-8581 Japan.
The title tells us that female feral cats avoid inbreeding through selection of their mate. In the study they observed eight female cats over their oestrous periods. They were courted by between 9-19 males. They had sex with 3-9 males.
The females, therefore, rejected some of the males who wanted to have sex with them. Their decision-making varied depending upon the point of being mounted by the male or at the point of copulation. And it varied depending upon the weight of the female and their age was also a factor.
Females with a shorter oestrous duration and who were lighter in body weight accepted mounts more frequently than females with longer oestrous duration and a higher body weight.
And older and lighter females tended to accept copulation more frequently than younger and heavier females.
When a female was courted by fewer males on a daily basis, they tended to accept copulations more frequently.
They decided that females avoided copulating with their kin (family and relations). They concluded that females avoided having sex with close relatives but not with distant relatives. They said that “Copulation attempts by kin males were less frequently accepted than those by non-kin males”.
They could not find any correlation between male age and body weight and their success in mating. Overall, they decided that “female cats control paternity of the offspring during copulation”.
In other words, it appears that female feral cats in colonies deliberately try and avoid mating with close relatives to avoid inbreeding. That’s my conclusion and it seems clear. The reason is most likely to be that inbreeding has a negative impact on the chance of offspring surviving. If the offspring are less likely to survive, the family is also less likely to survive. There is a natural urge to preserve the family and ensure that it survives into the future. That’s their bloodline and both male and female cats desire that it continues.
The reason why I asked the question and did the research is because a trustee of North Norfolk Cats Lifeline, Sandra Branch-Burbridge, said that her rescue was currently going through a period of a sharp rise in number of feral cats and she remarked that feral cats are bad for wildlife and that inbreeding among cat colonies could cause physical abnormalities and underlying health problems. I wanted to check whether this is true and it appears it is not entirely true, at least, because females take defensive measures against it happening.
P.S. The behavior of female feral cats is contrasted with female humans who create purebred cats (breeders of the cat fancy) that are deliberately inbred to enhance their appearance. Interesting don’t you think? Purebred cats are less healthy than moggies because of inbreeding depression.
SOME MORE ON COLONIES: