Terms & Definitions - Habitats, altitude and migratory status

Click on any of the following for some background and an explanation of the technical terms used in the species factsheets and additional data tables:

Habitats, Altitude and Migratory Status

In the species factsheets, details of the species's ecology are included, covering habitats used, diet and breeding details, especially where this information is relevant to the evaluation of the status of the species. In BirdLife's World Bird Database, habitat types are coded for analytical purposes. These are listed in the 'additional data' tables, along with codes for their importance and for describing the occurrence of the species in the habitat (see below). The habitat types used are listed below and are the standard terms used in the IUCN Red List Habitats (Version 3.1). The two levels of the hierarchy are self-explanatory, as they use familiar habitat terms that take into account biogeography and latitudinal zonation. The aquatic habitats, both marine and inland, are based primarily on the classification system of wetland types used by the Ramsar Convention (see http://www.ramsar.org/document/ramsar-information-sheet). It is acknowledged that the system is not perfect, and that the freshwater and marine habitats in particular need further development. Updates to this Authority File and a more detailed description of the habitat types can be downloaded from: http://www.iucnredlist.org/technical-documents/classification-schemes/habitats-classification-scheme-ver3

HABITATS - classification

1. Forest
1.1 Boreal forest; 1.2 Subarctic forest; 1.3 Subantarctic forest; 1.4 Temperate forest; 1.5 Subtropical/tropical dry forest; 1.6 Subtropical/tropical lowland moist forest; 1.7 Subtropical/tropical mangrove; 1.8 Subtropical/tropical swamp forest; 1.9 Subtropical/tropical montane moist forest

2. Savanna
2.1 Dry savanna; 2.2 Moist savanna

3. Shrubland
3.1 Subarctic shrubland; 3.2 Subantarctic shrubland; 3.3 Boreal shrubland; 3.4 Temperate shrubland; 3.5 Subtropical/tropical (lowland) dry shrubland; 3.6 Subtropical/tropical (lowland) moist shrubland; 3.7 Subtropical/tropical high altitude shrubland; 3.8 Mediterranean-type shrubland

4. Grassland
4.1 Tundra; 4.2 Subarctic grassland; 4.3 Subantarctic grassland; 4.4 Temperate grassland; 4.5 Subtropical/tropical (lowland) dry grassland; 4.6 Subtropical/tropical (lowland) seasonally wet/flooded grassland; 4.7 Subtropical/tropical high altitude grassland

5. Wetlands (inland)
5.01 Rivers, streams, creeks – permanent; 5.02 Rivers, streams, creeks -seasonal/intermittent/irregular; 5.03 Shrub dominated wetlands; 5.04 Bogs, marshes, swamps, fens, peatlands; 5.05 Freshwater lakes (>8 ha) – permanent; 5.06 Freshwater lakes (>8 ha) - seasonal/intermittent; 5.07 Freshwater marshes/pools (

6. Rocky areas

7. Caves and subterranean habitats (non-aquatic)
7.1 Caves; 7.2 Other subterranean habitats

8. Desert
8.1 Hot desert; 8.2 Temperate desert; 8.3 Cold desert; 8.4 Semi-desert

9. Sea
9.1 Open sea; 9.2 Shallow sea; 9.3 Subtidal aquatic beds; 9.4 Coral reefs

10. Coastline
10.1 Rocky shores; 10.2 Sand, shingle, pebble shores; 10.3 Estuarine waters; 10.4 Intertidal mud, sand/salt flats; 10.5 Intertidal marshes; 10.6 Coastal brackish/saline lagoons; 10.7 Coastal freshwater lagoons

11. Artificial landscapes (terrestrial)
11.1 Arable land; 11.2 Pastureland; 11.3 Plantations; 11.4 Rural gardens; 11.5 Urban areas; 11.6 Subtropical/tropical heavily degraded former forest

12. Artificial landscapes (aquatic)
12.1 Water storage areas (>8ha); 12.2 Ponds (<8ha); 12.3 Aquaculture ponds; 12.4 Salt exploitation sites; 12.5 Excavations (open); 12.6 Wastewater treatment areas; 12.7 Irrigated land; 12.8 Seasonally flooded agricultural lands; 12.9 Canals, drainage ditches, ditches

13. Introduced/exotic vegetation

14. Other

15. Unknown

Habitat Importance - BirdLife scores the importance of each habitat coded for each species as one of the following:

  • Suitable: The species occurs in the habitat regularly or frequently
  • Major: The habitat is suitable (q.v.), and furthermore it is important for the survival of the species, either because it has an absolute requirement for the habitat at some point in its life cycle (e.g. for breeding or as a critical food source), or it is the primary habitat (or one of two primary habitats) within which the species usually occurs or within which most individuals occur.
  • Marginal: The species occurs in the habitat only irregularly or infrequently, or only a small proportion of individuals are found in the habitat.
  • Unknown: The habitat is of unknown importance to the species.

Habitat seasonal occurrence - BirdLife scores the occurrence of the species in each habitat as one of the following:

  • Resident = known or thought to use the habitat throughout the year, including for breeding
  • Breeding = known or thought to use the habitat for breeding during the appropriate season
  • Non-breeding = known or thought to use the habitat, but not normally for breeding

ALTITUDE - Altitude is recorded as the altitude(s) at which the species usually occurs, excluding extreme records.


  • Nomadic -- Moves in response to resources that are sporadic and unpredictable in distribution and timing. Examples include Golden-plumed Parakeet. Nomadic species may congregate, but not predictably in terms of location and timing (e.g. Lesser Flamingo). Nomadic species usually cannot be conserved at the site scale alone. This excludes largely resident “environmental response migrants” (Dodman and Diagana 2007) i.e. species that are largely resident but move opportunistically in response to irregular environmental conditions such as rainfall, fire, locust eruptions etc. (e.g. Fulvous Whistling-duck).
  • Migratory -- A substantial proportion of the global or regional population makes regular or seasonal cyclical movements beyond the breeding range, with predictable timing and destinations. This includes species that may be migratory only in part of their range (e.g., German populations of the European Robin) or part of their population (e.g., White-starred Robin), short-distance migrants (eg Black Crowned-Crane) and migrants that occasionally may respond to unusual conditions in a semi-nomadic way (e.g. Sociable Lapwing). Migratory species may require conservation action (at specific sites, or beyond sites) along migration routes. Seabirds which disperse widely as immatures and non-breeders are not classified as migratory unless adults of the species make regular cyclical movements. In the definitions of Dodman and Diagana (2007), this excludes “rains migrant/arid migrant” species which move with unpredictable timing and destination in response to irregular rainfall patterns, “nutrition migrants/post-roost dispersers” i.e. species that disperse daily from roosts to forage, “post-breeding dispersers” which may not make cyclical movements i.e. dispersers that may not return to the same breeding area, and “environmental response migrants” i.e. species that are largely resident but move opportunistically in response to irregular environmental conditions such as rainfall, fire, locust eruptions etc. All such species should be coded as non-migrants.
  • Altitudinal migrant -- Regularly/seasonally makes cyclical movements to higher/ lower elevations with predictable timing and destinations. Examples include Three-wattled Bellbird. Partial altitudinal migrants might not be best conserved at the site scale alone, if individual sites do not encompass the full altitudinal range of the species.
  • Non-migratory -- Not nomadic (q.v.) or migratory (q.v).