A data deficient (DD)
species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
is one which has been
categorized by the
International Union for Conservation of Nature
The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the stat ...
(IUCN) as offering insufficient information for a proper assessment of
conservation status
The conservation status of a group of organisms (for instance, a species) indicates whether the group still exists and how likely the group is to become extinct in the near future. Many factors are taken into account when assessing conservation ...
to be made. This does not necessarily indicate that the species has not been extensively studied, but it usually indicates that little or no information is available on the
abundance and
distribution of the species. It can also indicate uncertainty about the taxonomic classification of an organism; for example, the IUCN classifies the
orca
The orca (''Orcinus orca''), or killer whale, is a toothed whale and the largest member of the oceanic dolphin family. The only extant species in the genus '' Orcinus'', it is recognizable by its black-and-white-patterned body. A cosmopol ...
as "data deficient" because of the likelihood that two or more
types of the whale are separate species.
The IUCN recommends that care be taken to avoid classing species as "data deficient" when the absence of records may indicate dangerously low abundance: "If the range of a taxon is suspected to be relatively circumscribed, if a considerable period of time has elapsed since the last record of the taxon, threatened status may well be justified"
["The Categories", in IUCN (1983).] (see also
precautionary principle
The precautionary principle (or precautionary approach) is a broad epistemological, philosophical and legal approach to innovations with potential for causing harm when extensive scientific knowledge on the matter is lacking. It emphasizes cautio ...
).
See also
*
IUCN Red List data deficient species
*
List of data deficient amphibians
*
IUCN Red List data deficient species (Annelida)
*
List of data deficient arthropods
*
List of data deficient birds
*
IUCN Red List data deficient species (Cnidaria)
*
List of data deficient fishes
*
List of data deficient insects
*
List of data deficient invertebrates
*
List of data deficient mammals
*
List of data deficient molluscs
*
List of data deficient plants
*
List of data deficient reptiles
References
External links
*
{{Portal bar, Ecology, Biology
IUCN Red List
Biota by conservation status