1.1 Factors effecting the size of animal populations
Animal population size is shaped by growth factors (like - birth and immigration) and population decline (like - deaths and emigration), all controlled by limiting factors like food supply, water, shelter, predation, diseases, space, as well as environmental conditions (climate, light) and biological interactions (competition, symbiosis) ultimately determining the habitat’s carrying capacity.
How food supply impacts growth: A) Food supply:
Food supply is a primary driver of animal population size; abundant food allows for more births and better survival, leading to population growth, while scarcity cause declines through starvation, reduced reproduction, and increased stress/predation.
B) Predators:
• Predation significantly effects animal population by creating dynamic cycles; more prey leads to move predators, which then reduces the prey to rebound, and restarting the cycle.
C) Diseases:
• Diseases effect animal populations primarily by increasing mortality (deaths), descreasing growth and reproduction rates, which can lead to significant population declines and, in rare cases, extinction. The specific impact depends on several factors related to the host, the pathogen, and the environment.