Here's a general overview:
* Red foxes: In the Northern Hemisphere, they typically go into heat between December and February. In the Southern Hemisphere, their breeding season is shifted accordingly.
* Arctic foxes: They breed during the winter months, often in March and April.
* Other fox species: Different fox species have varying breeding seasons, so it's important to look up the specific species you're interested in.
Factors influencing estrus:
* Daylight hours: The amount of daylight is a major factor in triggering estrus in many fox species.
* Geographic location: Foxes in different parts of the world will have different breeding seasons based on climate and food availability.
* Age: Young foxes typically don't reach sexual maturity until they are at least one year old.
* Individual variation: There can be some variation in the timing of estrus even within the same species.
If you are interested in knowing more about the breeding season of a specific fox species, I recommend consulting a reliable wildlife source or contacting a local wildlife expert.