NWT 2011-2015 - NWT Species at Risk

4. Data Sources and Methods – How did we rank species?
Evaluation Process
From Infobase to General Status Ranks
Guidelines were developed to convert data and information into seven indicators. These indicators were scored to produce a
status rank for each species. The seven biological indicators used to evaluate the biological status of a species are given below.
SIZE
1A Population Size = the current estimate of the total
number of mature individuals.
1B Number of Occurrences = the estimated number
of occurrences where the species currently persists. An
occurrence is a location or place where a species is found,
in which a single event may affect all individuals of the
population.
1C Distribution = the current range. In this report,
distribution was calculated as the percentage of total
NWT land or marine area covered by the range of the
species.
TREND
2A Trend in Population = an estimate of the observed
change in number of mature individuals over time.
2B Trend in Distribution = an estimate of the observed
change in area of range over time.
THREAT
3A Threats to Population = observed, inferred,
or projected factors affecting individuals or populations
that may result in population declines over the next
5 years.
3B Threats to Habitat = observed, inferred, or projected
habitat alterations that may result in population declines
over the next 5 years.
Each indicator was given a score according to the following
matrix. The scores were then converted into a general status
by following guidelines shown in the scoring matrix. As a
guide, the species is assigned the highest general status
(from May Be At Risk, Sensitive to Secure) reached using
any indicator.
8
NWT Species 2011-2015