Why r selected species tend to be opportunists

Opportunist or r-selected species Each species has a characteristic mode of reproduction. At one extreme are species that reproduces early and put most of their energy into reproduction. Species with such a capacity for a high intrinsic rate of increase r are called r-selected species. Algae, bacteria, rodents, annual plants such as dandelions and most insects are examples.

Such species tend to be opportunists. They reproduce and disperse rapidly when conditions are favorable or when a disturbance opens up a new habitat or niche for invasion, as in the early stages of ecological succession. Changed environmental conditions from disturbances can allow opportunist species to gain a foothold. However, once established, their populations may crash because of changing or unfavorable environmental conditions or invasion by more competitive species. Therefore, most r-selected species or opportunist species go through irregular and unstable boom-burst cycles in their population size.

To survive, opportunists must continually invade new areas to compensate for being displaced by more competitive species. Competitor or K-selected species At the other extreme are Competitor or K-selected species. This reproductive pattern results in a few big and strong individuals that can compete for resources and reproduce a few young to begin the cycle again.

Such species are called K-selected species because they tend to do well in competitive conditions when their population size is near the carrying capacity K of their environment. Their populations typically follow a logistic growth curve.

Examples are most large mammals, birds and large and long-lived plants such as the saguaro cactus, oak trees, redwood trees, and most tropical rain forest trees. Many K-selected species, especially those with long generation times and low reproductive rates such as elephant, shark, and rhinoceroses , are prone to extinction.

Most competitor or K-selected species thrive best in ecosystems with fairly constant environmental conditions. These species typically have little parental care and reproduce often. Examples include bacteria , many plants, and most insects.

R-selected species can be contrasted with k-selected species which have slower growth rates, produce few offspring with increased parental care and higher survival odds, and that reproduce at longer intervals. Examples of k-selected species include mammals such as humans, dolphins, and rhinos. What are opportunistic or r-selected species? R-strategists often live in unstable environments, so there's little chance that their offspring would survive into adulthood.

Organisms whose life history is subject to K-selection are often referred to as K-strategists or K-selected. Organisms with K-selected traits include large organisms such as elephants, humans, and whales , but also smaller long-lived organisms such as Arctic terns, parrots and eagles. Explanation: K-strategist populations are more commonly regulated by density-dependent limiting factors.

Their population sizes hover around a carrying capacity that is dependent on factors that increase in severity with the density of the population. The r and K strategists are two types of organisms categories under the basis of r and K selection.

On the contrary, K strategist lives in stable, predictable environments. Therefore, r strategist reproduces fast in order to ensure its survival. Other animals known as r-selected produce many young usually eggs that typically experience high mortality because they receive little or no parental care.

Butterflies, which are r-selected, normally experience high mortality throughout their life cycle. A theory in population ecology that attempts to establish whether environmental conditions favor the maximization of r the intrinsic rate of natural increase or of K the carrying capacity of the environment.

When populations can expand without food reserves limiting their growth, then r selection is in control. So, the correct answer is ' Large number of progeny with small size '. Note: - r-selected species are also called fugitive species or opportunistic species. Are dogs K or R strategists? Cats and dogs are r-selected compared to humans, but K-selected compared to mice and rats. Who do r-selected species tend to be opportunists?

Asked by: Tyrese Stoltenberg. Do humans exhibit traits of R or K selection? Are humans R strategists? Are cats K or R strategists?