Hi
It is unlikely they are related but not impossible.
Increasingly we are seeing that hogs will often share nests despite being solitary
Size isn’t sex related, it’s more likely due to the age of the hog and also how much food they’ve been getting
Hogs will build a different type of nest for hibernation called a hiberniculum. This is usually very dense in order to keep them safe and warm during hibernation. They can build several nests and will often get up and move to another one during hibernation. They will not eat during hibernation but may drink water.
Giving them more options in places to build nests is a great thing.
They don’t usually hibernate together, but again it’s no unheard of.
The BHPS and this site give good info on the hibernation cycle of a hog.
Also note that no matter size or anything hibernation is a dangerous time for a hog and not all survive, therefore anything we can do to help is a bonus. It is also not essential for them to hibernate so leaving a source of food and water during winter is a good thing to do
Hope this answers your questions
