Applied Population Biology

methods of monitoring populations

surveys and census

census

precise count of individuals in population; can measure population trends

survey

sampling method to estimate abundance or density; used to estimate population size for large populations or extensive ranges; ex. transects, quadrants, capture-mark-recapture, footprints

demographic studies

follows individuals to determine growth rate, fecundity, survival; usually marks; used to calculate rate of pop change & life cycle; provides most info but often incorrect

eDNA

environmental DNA; found in water/dirt samples from skin and waste; only found for known spp & only present for 1-2 weeks

iDNA

vertebrate DNA collected from parasitic invertebrates; ex. leeches retain host blood for many months

monitoring programs

have increased; long term programs distinguish between long and short term trends, & effects of monitoring programs

Population Viability Analysis (PVA)

extension of demographic analysis; uses math and stats models (deterministic and stochastic models) to predict probability of extinction or changes in pop, identify vulnerable stages, and effects of management

PVA sensitivity analysis

measures influence of particular parameters (uncertain and vulnerable areas); results change depending on assumptions and changing parameters; does not include full scope of parameters & prone to errors

metapopulations

one population consisting of multiple sub populations in fragmented area; changes in population due to sub population migration; requires habitat availability and connectivity

long term ecological research (LTER)

program that focuses on long terms reasons behind changes of highly variable population; monitors populations and environmental parameters; sites located in areas representative of major biomes

long term research in environmental biology (LTREB)

extends time series of data to address issues in evolution and ecology; can address changes due to climate change