Mating

Mating is the process of sexual reproduction in which two individuals produce offspring that inherit a selection of their parents’ genes. The type of mating system (e.g., monogamy, polygamy, polyandry) influences the number and sex of mates an individual has. The primary purpose of mate choice is to increase an individual’s fitness by selecting a high-quality mate who produces genetically compatible offspring with good survival prospects. However, other benefits can be gained from mate choice, such as increased access to resources or improved safety from predators. Some animals form lifelong bonds with their mates, while others only associate for a brief period prior to mating. Depending on the species, males and females may initiate mating interactions or one sex may be more passive and responsive to the other’s advances.
In many animals, including mammals and birds, males compete for access to reproductive females in what is known as intrasexual selection or sperm competition. This competition can take many forms, such as physical contests between males or indirect competitions in which males use gifts or displays to woo potential mates (see also male courtship behavior). Females often have some control over which male they will mate with and may base their decision on a variety of factors including genetic quality (e.g., compatibility), resource availability (e.g., food), and risk of predation (e.g., safety). In some cases multiple matings with different partners can occur within a single breeding season (polygynandry), while in others there is strict fidelity to just one partner over many years or even a lifetime (monogamy).
Mating systems are flexible and can change rapidly in response to shifts in conditions such as population density or changes in resource availability. For example, red deer living on small islands off the coast of Scotland have been found to exhibit different mating strategies depending on whether their island is large enough to support wintering herds of stags (a condition known as critical mass). When herd size falls below critical mass stags become much less aggressive towards each other outside the rutting season and instead focus on maintaining body condition so they will be able win future fights for dominance when conditions improve. This change in tactics allows them to maintain a higher rate of reproduction despite challenging environmental conditions..