There are many different ways, such as dying out or being alone with no mate.
Increase: Survival and Immigration Decrease: Death and Emigration
it will decrease population size
Population decrease in bowl by every 3 second millimeter. Size bowl important to population loss. Population decrease in bowl by every 3 second millimeter. Size bowl important to population loss.
By Genocide, and by war..
gene drift is when a population experiences a decrease in variation and population size.
Famine
Population sizes decrease at higher trophic levels. If they increased the insects population would decrease meaning there would be less food available for the birds so their population size would then decrease. Look at the relationships between predator and prey species for more information
Population sizes decrease at higher trophic levels. If they increased the insects population would decrease meaning there would be less food available for the birds so their population size would then decrease. Look at the relationships between predator and prey species for more information
limiting factor
Increase; decrease
I dont think its possible for the population to decrease because if people keep on having babies the population is just going to grow larger than what it was before.
Let's put it this way. Say you have a killerwhale and a penguin. Killerwhales are major predators to penguins. Now, say the killerwhale population increases. The penguins would be eaten more by the killerwhales, then causing a population decrease for the penguins. If the population decreases, they're won't be enough penguins, and they most likely will become extinct, as well as causing a population decrease for the killerwhales as well. Whereas, vis versa, they're were a killerwhale population decrease. The penguins would be less hunted, therefore, creating a population increase for the penguins.