What is compensatory mortality?

Compensatory mortality means that instead of adding additional mortality to the population (i.e., additive mortality), increases in predation result in compensatory declines in other causes of mortality.

Is hunting a compensatory or additive mortality?

additive mortality. Applied managers will usually consider hunting harvest to be largely compensatory (“animals would have died anyway”); basic (meaning studying a problem for its own sake, as opposed to applied) biologists will often consider any source of mortality they measure as being additive.

What causes Allee effect?

The most commonly observed mechanism is mate limitation, which causes Allee effects in both animals and plants (in the form of pollen limitation). Positive density dependence in survivorship due to either cooperative defense or predator satiation is also found across taxonomic groups.

What is doomed surplus?

Doomed Surplus Concept. the idea that predation can no effect or have a positive effect, by removing diseased or weak individuals from the population, or by limiting number of babies and allowing the population size to stay constant.

What are examples of predation?

The best-known examples of predation involve carnivorous interactions, in which one animal consumes another. Think of wolves hunting moose, owls hunting mice, or shrews hunting worms and insects. Less obvious carnivorous interactions involve many small individuals consuming a larger one.

What is selective mortality?

Selective mortality is a process whereby disadvantaged individuals die at younger ages than their more advantaged peers.

What is a harvestable surplus?

Nearly 100 years ago Aldo Leopold, the father of game management, coined the term “harvestable surplus.” The intended meaning of the term is that some wildlife species and populations may produce more young in a given year than can survive to the following year.

What is harvest rate?

Harvest rate means the amount of ice (at 32°F) in pounds produced per 24 hours.

What is the Allee effect example?

The demographic Allee effect is the positive relationship between the overall individual fitness and population density. For example, cooperative hunting and the ability to more easily find mates, both influenced by population density, are component Allee effects, as they influence individual fitness of the population.

What is the metapopulation theory?

Metapopulation, in ecology, a regional group of connected populations of a species. Extinction of local populations is common in some species, and the regional persistence of such species is dependent on the existence of a metapopulation.

How can predation be positive?

Traits associated with improved predation for predators and escaping predation for prey tend to be positively selected by natural selection. Predators exhibit traits such as sharp teeth, claws, and venom that enhance their ability to catch food.

What are 5 example of predation?

Some examples of predator and prey are lion and zebra, bear and fish, and fox and rabbit. The words “predator” and “prey” are almost always used to mean only animals that eat animals, but the same concept also applies to plants: Bear and berry, rabbit and lettuce, grasshopper and leaf.

How does compensatory mortality affect the management of species?

Because compensatory natural mortality reduces the managers’ability to control annual mortality, we suggest that further consideration of the compensatory mortality hypothesis be given to species that have shown variable mortality responses to reductions in annual exploitation.

Is there evidence for compensatory or additive mortality?

We reviewed mortality estimates for some prominent sportfish populations to identify evidence for compensatory or additive mortality. For largemouth bass Micropterus salmoides, total annual mortality increased with annual exploitation suggesting additive mortality.

Why is predation considered compensatory at the level of the population?

Predisposition is necessary for predation to be compensatory, or substitutive, at the level of the population. Compensatory mortality means that instead of adding additional mortality to the population (i.e., additive mortality), increases in predation result in compensatory declines in other causes of mortality.

Why are mortality lines compensatory for density dependence?

along with the density-independent situation where no response in survival is allowed as a function of population size. These lines are labels compensatory for density dependence and additive for density independence because these are the underlying assumptions that result in compensatory and additive mortality.