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A population cycle in zoology is a phenomenon where populations rise and fall over a predictable period of time. There are some species where population numbers have reasonably predictable patterns of change although the full reasons for population cycles is one of the major unsolved ecological problems.
Population size can be influenced by the per capita population growth rate (rate at which the population size changes per individual in the population.) Births, deaths, emigration, and immigration rates all play a significant role in growth rate. The maximum per capita growth rate for a population is known as the intrinsic rate of increase.
Ecologists have been unable to successfully explain regular population cycles for many decades; delayed density dependence may hold the answer. [2] Here populations are allowed to increase above their normal capacity because there is a time lag until negative feedback mechanisms bring the population back down.
In ecology, overpopulation is a concept used primarily in wildlife management. [1] [2] Typically, an overpopulation causes the entire population of the species in question to become weaker, as no single individual is able to find enough food or shelter. As such, overpopulation is thus characterized by an increase in the diseases and parasite ...
Microclimatic changes in light, temperature, and wind can alter the ecology around the fragment, and in the interior and exterior portions of the fragment. [22] Fires become more likely in the area as humidity drops and temperature and wind levels rise. Exotic and pest species may establish themselves easily in such disturbed environments, and ...
The genetic drift caused by a population bottleneck can change the proportional random distribution of alleles and even lead to loss of alleles. The chances of inbreeding and genetic homogeneity can increase, possibly leading to inbreeding depression. Smaller population size can also cause deleterious mutations to accumulate. [3]
China's population is projected to crash 55% by the turn of the next century. Italy's will sink 41%, and Brazil's will drop 23%. ... "Absent changes, increasing numbers of seniors will cause ...
In population ecology, density-dependent processes occur when population growth rates are regulated by the density of a population. [1] This article will focus on density dependence in the context of macroparasite life cycles.