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Part Three: indicators
lEvEl Of MEAsurEMEnT: Outcome.
dEfiniTiOn: Species monitoring should include assessments of species' population structure (e.g.,
breeding, mortality, or age-structure), taking into account spatial and temporal changes. The most ap-
propriate indicators for monitoring species' population structure will vary depending on the threats to
the local species of interest and the life-stage the threat is most likely to impact. When baseline knowl-
edge is sufficient and the main local threats are fully known, the most effective monitoring should
focus on the life-stage most affected by the threat. A combination of short- and long-term (e.g., nest
monitoring over time, change in the proportion of occupied territories) indicators are needed.
Population structure measures will vary depending on the species. Specific measures may include
things such as den or nest occupancy rates during the breeding season; territory occupancy and re-
occupancy rates; nesting status; number of eggs in nest, average number of offspring produced per
territory size in hectares; fledgling or cub survival; sex-ratios of offspring; ratio of pre-adults to adults;
and age-specific survival, number of adults in population, etc. All of these would need to be measured
repeatedly over time.
disAGGrEGATE: Type of species; target area (if desired).
PurPOsE: Changes in wildlife health may serve as early warnings for factors that can also affect human
health. Reproductive health is especially sensitive to threats (e.g., pollutants, lack of sufficient food or
water, changes in predator dynamics, etc) and thus measuring reproductive health of species can serve
as an early warning of potential problems. Species that are successfully breeding and maintaining their
numbers are an ecological indicator of ecosystem health. The number of breeding species is gener-
ally related to the available area of land. Thus, these indicators serve as measurable surrogates for the
health of the environment.
Population structure and reproductive health/behavior may be susceptible to changes in a particu-
lar environmental stressor or reductions in a key resource. Species monitoring can detect ecosystem
disturbance before it is too severe. If species are able to grow to maturity and to increase in overall
numbers (richness) and abundance then this may lead to increased reproductive potential.
dATA sOurCEs: Various combinations of data may be used, including:
transect surveys
·
existing species data
·
qualitative interviews with community
·
catch and release (e.g., to measure offspring sex ratios)
·
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POPulATiOn sTruCTurE Of sPECiEs