Here's why:

* Biotic factors are living organisms or their products that affect an organism's survival and reproduction.

* Abiotic factors are non-living components of the environment, such as temperature, sunlight, and water.

Competition for mating involves interactions between living organisms. It's a direct struggle between individuals of the same species (intraspecific competition) or different species (interspecific competition) for access to mates.

Examples of biotic competitors for mating:

* Males competing for females: This is common in many animal species, with males often displaying elaborate behaviors, fighting, or offering gifts to attract females.

* Females competing for males: This is less common but can occur in species where females are more selective or where resources are limited.

Therefore, competition for mating is a biological interaction between living organisms and is thus a biotic factor.