Here's why they don't have many mates:
* Limited mating opportunities: Polar bears live in a harsh environment with low population densities, making it difficult to find mates.
* Pair bonds: Once a pair bond is formed, they stay together for the mating season and sometimes even longer.
* Long lifespan: While not necessarily a factor in the number of mates, the fact that polar bears can live for 20-30 years in the wild means they have enough time to potentially form a few pair bonds in their lifetime.
It's important to note that:
* While one mate is the norm, there are instances of polygamy (multiple mates) in rare cases. This is usually when there is a shortage of females in a particular area.
* Pair bonds are not always permanent. Sometimes, the pair may separate after the mating season.
Overall, it's safe to say that polar bears usually have one mate at a time throughout their lifetime.