#r-strategists

Survivorship and rK Strategies

CSIR-NET: Which trait is NOT typical of r-strategists?

Density-dependent mortality is not part of the classic r-selected syndrome emphasized for organisms in ephemeral habitats. r strategists are expected to encounter substantial density-independent mortality from disturbance, weather, or temporary resource loss, often before crowding becomes decisive. Rapid development, strong dispersal, and effective colonization help them exploit newly available sites where competition is initially weak. Survivorship and reproductive schedules are connected through allocation. An organism has finite energy for growth, maintenance, defense, and reproduction; inv

Ref: Ecology: Concepts and Applications, Molles, 9th Ed., Ch. 12

View Details

Survivorship and rK Strategies

Which trait is NOT typical of r-strategists?

High parental investment is inconsistent with the usual r-selected syndrome. Early reproduction, short generation time, many small offspring, effective dispersal, and use of disturbed habitats all promote rapid colonization. Extensive care consumes time and energy per offspring, reduces the number produced, and is more characteristic of the K-selected end, where competition is intense and survival of each juvenile has high value. Life-history traits should be interpreted as correlated tendencies rather than rigid packages. Adult survival, juvenile mortality, body size, development time, fecund

Ref: Ecology: Concepts and Applications, Molles, 9th Ed., Ch. 12

View Details

Survivorship and rK Strategies

In r-strategists, population size is usually:

Populations described as r-selected often fluctuate widely. Their rapid reproduction permits abrupt increases after rain, disturbance, or release from enemies, but short-lived resources and density-independent events can cause equally abrupt declines. Such populations need not cycle regularly; variable captures their tendency to track unpredictable opportunities rather than remain close to a stable carrying capacity. A survivorship curve is built from a cohort life table by plotting the proportion alive at each age. Type I concentrates mortality late, Type II approximates a constant hazard, an

Ref: Ecology: Concepts and Applications, Molles, 9th Ed., Ch. 12

View Details

Survivorship and rK Strategies

Which of these is NOT a trait of r-strategists?

The keyed exception is “High parental care.” In the context of which of these is not a trait of r-strategists, that statement differs from the governing ecological pattern and must be evaluated against the mechanism rather than accepted from wording alone. Life-history traits reflect allocation among growth, maintenance, survival, and reproduction. Energy invested in many offspring cannot simultaneously be invested in large offspring, prolonged care, or future breeding, creating measurable trade-offs. The remaining alternatives—“High dispersal ability”, “High reproductive rate”, “Small body si

Ref: Ecology: Concepts and Applications, Molles, 9th Ed., Ch. 12

View Details

Survivorship and rK Strategies

The r in r-selection stands for:

“Growth rate” for the r in r-selection stands for. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. Selection favors the schedule that increases lifetime reproductive success under local mortality and resource conditions. Body size, development time, fecundity, parental investment, and generation length consequently tend to covary. The remaining alternatives—“Reproductive energy”, “Resource richness”, “Resistance”—refer to different states, processes, or scales and therefore do not express the same

Ref: Ecology: Concepts and Applications, Molles, 9th Ed., Ch. 12

View Details