This is an often overlooked aspect of the biology of a plant or animal that means activity in a day or season…or the amount of light there is in a day or a season.
Scientists refer to this as photoperizm or photoperiodicity. Birds are heavily reliant on this and it is used by mammals also.
Photoperiod may tell birds wnen to migrate, when to breed, food availability and so on. Photoperiod will tell mammals, like bears, when to hibernate, or when your body needs more noureshment and extend its feeding by going into a state of hyperphagia.
This photoperiodizm is one of the first things to be negativley impacted by global climate change…a little known process that is already happening.
photoperiod will tell