Chapter 6 Populations Flashcards
What is the definition of a population?
All coexisting individuals of the same species living in the same area at the same time.
What precedes extinction in populations?
Decline.
Define ‘cohort’ in the context of populations.
Group of individuals born at the same time.
What is recruitment in population dynamics?
Individuals added by birth, adjusted for early or neonatal mortality influenced by fecundity.
What is dispersal?
Permanent movement of an organism from its area of birth, including immigration and emigration.
What factors are measured in dispersal?
- Rate * Distance * Direction
What is the formula for the rate of increase (r)?
Difference between the rate of birth and rate of death.
What is logistic growth?
Population growth that reflects equilibrium between a population and its resources (takes into account K, carrying capacity).
What does ‘K’ represent in logistic growth?
Carrying capacity.
What are deterministic and stochastic factors in population dynamics?
- Deterministic: Non-random influences
- Stochastic: Random influences
What is demographic stochasticity?
Random fluctuations in birth and death rates, emigration and immigration, or sex ratio and age structure.
What is environmental stochasticity?
Fluctuations in the probability of birth and death due to temporal variation of habitat parameters.
What is a critical age group in population dynamics?
A specific age group that the density dependence of a population responds to.
What are metapopulations?
A population existing as spatially disjunct subunits at different densities in habitat patches.
List the four conditions for classical metapopulations.
- Discrete habitat patches must support breeding populations * Breeding assemblages must be prone to extinction * Recolonization of any habitat patch must be possible * Subpopulation dynamics must be asynchronous
What is the difference between source-sink and mainland-island models?
- Source-sink: Large populations supply individuals to small, extinction-prone populations * Mainland-island: A large, persistent population provides individuals to surrounding island populations.
What is the mark and recapture method?
Estimate the size of a population by capturing, marking, and releasing individuals.
What does occupancy theory describe?
The need for multiple surveys to accurately estimate population size due to detection probability.
What is a minimal viable population?
Population sizes of 50 required to prevent inbreeding effects; minimum size of 500 to maintain genetic variation.
What is population viability analysis?
Analytical models that estimate the probability of species persistence within a defined time period.
Define conservation reliant species.
Species that depend on ongoing management action to maintain their trajectory toward recovery.
What are the four elements required for a Conservation Management Agreement?
- Partnership agreement * Management plan * Sufficient funding * Legal enforcement
True or False: Stochastic factors influence population size by chance.
True.
