E

Ecological Niches

specific micro-habitats in nature to which populations or organisms adapt. They are usually seen in terms of being food getting opportunities in the environment.

Estrus

the period of time when female animals are sexually excited and receptive to mating. Estrus occurs around the time of ovulation in many species.

Estrus Swellings

Swelling of the perineal region that occurs for a variable period around ovulation. Highly visible and may also involve pheromones.