One exception to the general rule of K-strategists being less likely to exhibit irruptive growth is people.

The third, and perhaps the most beautiful, of the 'irruptive' species is the waxwing.

If there is a change in their environment, more of these offspring may survive than is typical, leading to irruptive growth.

Red Crossbills too are irruptive, with invasions noted in 1251, 1593, 1757, and 1791.

Irruptive growth occurs when a species reproduces more rapidly than the environment is capable of supporting with the available resources.

Irruptive growth is studied in population ecology.

Another phenomenon of late summer and autumn is the arrival of so-called 'irruptive' species.

It is nomadic and sometimes irruptive.

Due to the irruptive nature of this species, populations vary widely from year to year, and trends can be difficult to interpret.

Populations which exhibit irruptive growth do not stabilize around their carrying capacity, a feature of logistic growth.

Irruptive growth patterns are seen in a few mammal species, often in specific locations, and they are usually herbivores with relatively small body size.

Their numbers fluctuate during drought and floods, and can be irruptive in response to sudden increases in mouse populations.

Parrots as a family are overwhelmingly neither migratory nor sedentary but considered to either be dispersive, irruptive, nomadic or undertake small and irregular migrations.

Larger herbivores like pronghorn and deer are also known to exhibit irruptive growth; this occurs in populations with high reproduction and delayed density dependent inhibition.

Irruptive species such as the boreal finches are one such group and can commonly be found at a location in one year and absent the next.

Irruptive growth, sometimes called Malthusian growth, is a growth pattern over time, defined by population explosions and subsequent sharp population crashes, or diebacks.

The process, from introduction of the alien animals to accommodation between animals and plants, takes between 35 and 40 years and is called an irruptive oscillation.

In the meantime, concern and suspense and irruptive wrath had their chief abode in the inner room of Remington and Evans.

The Letter-winged Kite (Elanus scriptus) is a small, rare and irruptive Australian raptor with a core range in central Australia.

This species is irruptive, with erratic winter movements, though most of the population bird migration further south into the United States and beyond, sometimes reaching as far as northern South America.

Because of these differences in the number of offspring produced between K- and r-strategists, K-strategist species are more likely to have stable populations and less likely to exhibit irruptive growth.

If there is more than sufficient to enable the animals to replace the population, the ungulate populations enter what is known as an irruptive phase and begin to increase at remarkably rapid rates.

Unlike the Green-faced Parrotfinch E. viridifacies, it does not appear to be strongly allied to bamboo, and is therefore less irruptive, unpredictable and inherently vulnerable than that species.

Irruptive migrations don't seem to follow any pattern at all, and nomadic species move from place to place whenever they've exhausted the food supply in one area [source: National Park Service].