Hi Jackietb
Good to hear it really is a hog!
If the hog has already selected the igloo to nest in, I wouldn’t put covers over the top. They are experts at nest building. If you imagine that they were building a nest naturally, for instance in the bottom of a hedge, it wouldn’t have any waterproofing etc. Hogs build their hibernation nests to be very well insulated and water proof and that will have taken into account the existing conditions. To the hog, the igloo is just a convenient structure within which to build a nest.
Yes, the hog may find it helpful if you put a pile of leaves nearby, as well, so that it can use them if it chooses. They prefer medium sized leaves. Normally that’s what they would use, mainly, to build their nests and because of the way they can layer them, they are useful for keeping the nest dry. You’ll probably find that they use far more material than you expect because of the way that they closely pack the nesting material.
The hog doesn’t need to be warm during hibernation. In fact it needs not to be too warm. They don’t actually sleep, as such, it is just that their bodily functions slow right down, including their body temperature lowering. So that if they become too warm, they might come out of hibernation.
Once the hog has hibernated, I would keep a look out to see whether it emerges, so that you can offer food again. I would leave a constant source of water available. Hogs will come out of hibernation for short periods and sometimes even change nests. I tend to leave my cameras working all winter, so that I can see if any hogs are up and about.
Good luck. Fingers crossed for a successful hibernation.
