NWT 2011-2015 - NWT Species at Risk

4. Data Sources and Methods – How did we rank species?
Status Rank Categories
Priorities for Study and Management
Each species was placed into one of ten standard rank categories:
1) At Risk = species for which a detailed assessment has
already been completed (e.g., by COSEWIC or jurisdictional
status reports) that determined the species to be at risk of
extirpation or extinction. This is a special category used
only for species that have been assessed as “Endangered”
or “Threatened” according to COSEWIC, or according to
SARC in the NWT.
Categories determined
using the scoring matrix
2) May Be At Risk = species that may be at risk of extinction
or extirpation, and are therefore candidates for detailed risk
assessment. This is the highest rank that can be given to a
species using the General Status Ranking system independent
of a more detailed assessment as noted in the At Risk category.
These species are ranked with the highest priority
for a more detailed assessment by COSEWIC in Canada
or SARC in the NWT.
3) Sensitive = species that are not at risk of extinction
or extirpation but may require special attention or protection
to prevent them from becoming at risk.
These species are ranked with a medium priority for
a detailed assessment.
4) Secure = species that are not at risk or sensitive.
These species have the lowest priority for a detailed
assessment.
The evaluation process was similar for each group of
species. The scoring process was performed with the help
of several experts and knowledgeable persons listed in the
acknowledgement section at the end of the report. More
information on guidelines and processes can be found in
Carrière and Lange (2002).
Categories determined
using its definition only
5) Undetermined = species for which insufficient information,
knowledge, or data is available to reliably evaluate their
general status.
6) Not Assessed = species which have not been examined for this
report. Due to time constraints, some species have not been
assessed for the present report. This information provides a list
of species that should be examined soon.
7) Alien = species that have been introduced as a result of human
activities. Most alien species have been introduced to North
America from Europe and Asia. Changes in the number of alien
species can be monitored as their presence and abundance may
affect the status of wild species native to the NWT. Synonymous
with exotic or introduced.
8) Extirpated/Extinct = species no longer thought to be present
in the NWT (extirpated) or are believed no longer present
anywhere in the world (extinct).
9) Vagrant = species occurring infrequently and unpredictably
in the NWT. These species are outside their usual range.
Synonymous with accidental.These species may be in the
NWT due to unusual weather occurrences, an accident
during migration, or unusual behaviour by a small number of
individuals. If a species appears in the NWT with increasing
predictability and more frequently, it may eventually be given
a different rank. Changes in the number of vagrant species may
be a good indicator of general ecosystem or climatic change.
10)Presence Expected = species not yet recorded in the NWT,
but are expected to be present. These species are expected
in the NWT due to their presence in adjacent jurisdiction(s),
the presence of appropriate habitat in the NWT, and other
evidence. The status rank is used to list species for which we
need firm evidence of their presence in the NWT. They form
a “Look For” species list. When a new species is found in
the NWT, the list of “Presence Expected” species is useful to
differentiate between species that may have been in the NWT
all along but simply had not been confirmed, and species that
are truly new to NWT and may indicate that ecosystems are
changing. This is a new rank category developed in 2005 for
the NWT; no other jurisdictions in Canada have adopted it yet.
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NWT Species 2011-2015