This variation in density is important to both the species in question and its predators. With its relatively high ecological density, the forager merely has to know its specific habitat. Related to ecological density but on a finer scale is the internal distribution of the population. While populations may fluctuate widely over short time spans, on the average they do not change significantly over a long time span. Thus, on the average each pair of titmice will produce, during their lifetime, one pair of reproducing offspring.
Reproductive strategies vary greatly.
Titmice may only produce two dozen eggs over a lifetime while some marine fish will produce over two million eggs per year. A redwood tree may produce 10,000 seeds per year over a period of 1000 years. Whatever the strategy, the biotic potential is matched by death of eggs or offspring so that each generation merely reproduces itself. Otherwise the world would be solid maple trees or they would go extinct. Alternatively, the increased population may support a larger population of predators that help increase d .