The number of individuals in a species that are found in a given area; abundance is often measured by population size or population density.
clone
A genetically identical copy of an individual.
clumped dispersion
A dispersion pattern in which individuals are grouped together. Compare random dispersion, regular dispersion.
cooperative breeding
A behavioral pattern in which young animals postpone breeding and instead help their parents raise offspring.
detritus
Freshly dead or partially decomposed remains of organisms.
dispersal limitation
A situation in which a species’ limited capability for dispersal prevents it from reaching areas of suitable habitat.
dispersion
The spatial arrangement of individuals within a population.
distribution
The geographic area where individuals of a species are present.
disturbance
An abiotic event that kills or damages some organisms and thereby creates opportunities for other organisms to grow and reproduce.
ecological niche
The physical and biological conditions that a species needs to grow, survive, and reproduce.
genet
In plants and animals that reproduce asexually, the entire genetic individual; a genet may consist of multiple, genetically-identical parts, each of which has the potential to function as an independent physiological unit. Compare ramet.
geographic range
The entire geographic region over which a species is found.
mark–recapture
An approach to estimating population size in which a subset of the individuals in a population are captured, marked, and released; after a suitable period of time, individuals are then captured again, and the proportion of marked individuals found in the second capture is used to estimate the population size.
niche model
A predictive tool that models the ecological niche occupied by a species based on the conditions at localities the species is known to occupy.
population
A group of individuals of the same species that live within a particular area and interact with one another.
population density
The number of individuals per unit of area.
population size
The number of individuals in a population.
quadrat
A sampling area (or volume) of any size or shape.
ramet
An actually or potentially physiologically independent member of a genet that may compete with other members for resources. Compare genet.
random dispersion
A dispersion pattern that is similar to what would occur if individuals were positioned at locations selected at random. Compare clumped dispersion, regular dispersion.
regular dispersion
A dispersion pattern in which individuals are relatively evenly spaced throughout their habitat. Compare clumped dispersion, random dispersion.
relative population size
An estimate of population size based on data that are related in an unknown way to the absolute population size, but can be compared from one time period or place to another.
