There is no secret method or clever strategy as to how feral cats survive the winter cold. Firstly they have their winter coats, a three tier fur coat with downy fur next to their skin. And they manage by finding the warmest place they can which provides some cover such as underneath buildings, inside old abandoned cars, even inside car engines, in barns and sheds, in abandoned buildings, in dense undergrowth and in shelters made by people.
The last item may be more important than people think. We don’t know how many home-made feral cat shelters there are in countries such as America, Canada and the UK. I have a sneaking suspicion that they play a significant role in helping feral cats survive very cold winter weather. They get help from people, that’s important.
But some must die during the winter. Feral cats are very tough as are domestic cats and they will make it through very cold nights in the winter but if they are ill they might die. So some don’t survive the cold weather. Most survive and some die is the way I see it.
An underlying factor is that whenever resources allow feral cats set up a complicated society called a colony. A supply of food is the most important resource and shelter is also important. So you’re going to see feral cats in abandoned buildings in old barns supported by volunteers who provide TNR services and food which is part of the package.
That’s probably a classic scenario as to how feral cats survive the winter weather. It is perhaps as good as it gets for a feral cat. And it is notable that within the colony there is extensive co-operation between adult females in the care and rearing of kittens. Although they don’t normally give birth in the winter. But there is support for each other.
Stray and feral cats have the ability to survive -20°C on a regular basis it seems to me. And some of them don’t want to use home-made shelters and prefer to sleep under a bush. While others may want to come inside and be adopted. But the hardiness of the cat both feral and domestic is legendary.
One problem in answering the question is that we don’t know how many feral cats die during very cold winters in countries like Canada. Some people say that most of them don’t and the lucky few have access to some form of shelter and support from volunteers. So we can’t answer the question accurately. We don’t have statistics on the percentage of those that die compared to the overall number.
One commenter who describes herself as “an animal who likes other animals” (I like that) wrote that “Anywhere they can find shelter and hopefully warmth. Many of them freeze to death, especially the old and young, because they’re outcompeted for shelter by the healthier cats”.
Another agreed with her saying that many freeze to death. This woman does her bit by using a large dog house as a shelter and putting hay inside and wrapping the entire construction in a tarpaulin. She keeps it behind bushes. Six cats use the home-made cat home when it gets really cold. That tells a story too. If you put enough cats into a relatively small space they heat it up with their body heat.
This brings to mind the need to create a home-made shelter which is the right size. If it’s too big it allows body heat to dissipate. If it is the right size the body heat is retained around the cat by the construction which helps to keep them warm.
There are a lot of very kind people who can’t live contentedly while knowing that feral cats are suffering during a very cold winter night and some are dying. This motivates them to do something about it such as the husband of a lady who wrote that, “They survive because of people like my husband, who twice a day, rain or shine, snow or sleet, regardless of the temperature, will put food and fresh water out for them, not to mention he has installed a pet door in the garage…”. Inside the garage he had constructed some home-made shelters. That is one, important way that many feral cats survive subzero temperatures during winter.