Western Governors’

Crucial Habitat Assessment Tool

Mapping Fish and Wildlife Across the West

Data

Crucial Habitat Regional Roll-Up

The Western Governors’ Wildlife Council has agreed to common definitions of crucial wildlife habitat and corridors and issued guidelines to help each state prioritize habitat within its boundaries to meet its specific conservation objectives. The West-wide definitions support compatibility and consistency across state boundaries and address certain discrepancies that may exist in identifying habitat and natural features along state borders. This broad-based, collaborative effort across 16 states has resulted in a west-wide crucial habitat data layer derived from important habitat and connectivity input layers. Click here for more detailed metadata on the west-wide crucial habitat data as well as state-specific metadata.

Crucial habitat datasets from all WGA member states were reviewed and approved as of November 4, 2013.

ESOC:Ecological System(s) of Concern
GAP:Gap Analysis Program coordinated by the US Geological Survey
NHD:National Hydrography Dataset
NHP:Natural Heritage Program
NFHAP:National Fish Habitat Action Plan. NFHAP assessment of watershed condition at HUC-12 level was used by some states in crucial habitat
NWI:National Wetland Inventory
LIB:Large Intact Block (as defined by WGA Landscape Integrity workgroup or other state data source)
SERI:Species of Economic and/or Recreational Importance, as defined in WGWC "White paper"
SGCN:Species of Greatest Conservation Need as defined in State Wildlife Action Plans (SWAPs)
SOC:Species of Concern, as defined in WGWC "White paper"
USFW:United States Fish and Wildlife Service
USGS:United States Geological Survey
WGA:Western Governors’ Association
WGWC:Western Governors’ Wildlife Council
  • E = Endangered, federal or state
  • T = Threatened, federal or state
  • C = Candidate, federal or state
  • S Rank = State conservation status (Natureserve)
    • S1: Critically Imperiled
    • S2: Imperiled
    • S3: Vulnerable
    • S4: Apparently Secure
    • S5: Secure
  • G Rank = Global conservation status (Natureserve)
    • G1: Critically Imperiled
    • G2: Imperiled
    • G3: Vulnerable
    • G4: Apparently Secure
    • G5: Secure

For more information, please see the Western Governors’ Wildlife Council’s White Paper, which serves as the primary guidance document for the CHAT.

Additive (weighted sum) Crucial Habitat Roll-up Method
Uses a mathematical equation to combine input data layers into a final aggregated crucial habitat rank for each hexagon. Each layer is weighted by importance relative to another.
Aggregated Data Layer
A spatial dataset comprised of more than one input dataset combined using an additive or categorical method.
Categorical Crucial Habitat Roll-up Method
Uses a non-mathematical set of rules to combine individual input data layers into a final aggregated crucial habitat layer for each hexagon.
Connectivity
Refers to the ease of movement for fish and wildlife species across the landscape. Landscape connectivity describes ease of movement based on landscape condition, where development or other human-caused alteration is expected to impede movement. Wildlife connectivity describes ease of movement based on species-specific habitat preferences and behavior. Well-connected habitats provide for higher quality ecological and biological processes.
Crucial Habitat
Places that are likely to provide the natural resources important to aquatic and terrestrial wildlife, including species of concern, as well as hunting and fishing species.
Ecological Integrity
The structure, composition and function of an ecosystem which determines its ability to provide for a variety of ecological and biological processes.
Empirical Data
Data collected in the field. Indicates a feature that has been verified to exist at a given location based on a documented, confirmed observation.
Important Connectivity Zones (ICZs)
Data layer representing buffered landscape pathways connected to core habitats of Large Intact Blocks. WGA Landscape Integrity Workgroup created a west-wide data layer by ranking ICZs based on strength of centrality (or “flow lines”), landscape condition within the ICZ, and Euclidean distance/length of each ICZ.
Landscape Condition
A measure of land cover impacted by human activities associated with ecological stressors. WGA Landscape Integrity Workgroup used a NatureServe landscape condition model to identify Large Intact Blocks and Important Connectivity Zones.
Landscape Condition Summary
Aggregated measure of landscape integrity data layers (for example, Large Intact Blocks; Ecological Systems of Concern; Important Connectivity Zones; etc), using the minimum criteria for an individual data layer.
Large Natural Areas
Large Intact Blocks or other dataset that identifies large areas of native habitat that are relatively intact or have low levels of anthropogenic impact.
Landscape Connectivity
Landscape - scale permeability or connectivity. States may have used their own dataset mapping connectivity, or may have used the WGA Landscape Integrity Workgroup’s map of Important Connectivity Zones.
Modeled Data
Data generated by computer modeling. Indicates a feature that is expected to occur at a given location based on our best understanding of species habitat requirements and/or natural resource features on the landscape.
Roll-Up
Method of combining, or aggregating, several different data inputs into a final score or ranking.
Species Occurrence
A mapped location in which a species or natural community has been documented by a verified field observation.
Species of Concern
Species of state and/or national conservation importance, including those vulnerable to extinction or those undergoing regional decline or other species requiring special management attention. Most states defined their Species of Concern list using State Wildlife Action Plan "Species of Greatest Conservation Need" and NatureServe conservation status rankings, and other criteria in some cases. Individual species are not depicted but the resources section of this site contains information specific to the Greater Sage Grouse and the Lesser Prairie Chicken.
Terrestrial Species of Concern
Species of state and/or national conservation importance that occur on land. May include birds, mammals, amphibians, reptiles, insects, plants and invertebrates.
Aquatic Species of Concern
Species of state and/or national conservation importance that occur in water. May include native freshwater and anadromous fishes; freshwater mussels and snails; crayfish; fairy, clam or tadpole shrimps; and aquatic insects.
Landscape Condition
A measure of land cover impacted by human activities. WGA Landscape Integrity Workgroup used a NatureServe landscape condition model to identify Large Intact Blocks and Important Connectivity Zones.
Large Natural Areas
Large Intact Blocks or other dataset that identifies large areas of native habitat that are relatively intact or have low levels of anthropogenic impact.
Natural Vegetation Communities
Dataset mapping natural vegetation communities of conservation concern, which may include clusters or patches of a natural community. States may have their own datasets mapping natural communities, or may have used the WGA Landscape Integrity Workgroups’ Ecological Systems of Concern map.
Landscape Connectivity
Landscape - scale permeability or connectivity. States may have used their own dataset mapping connectivity, or may have used the WGA Landscape Integrity Workgroup’s map of Important Connectivity Zones.
Landscape Condition Summary
Aggregated measure of landscape integrity data layers (for example, Large Intact Blocks; Ecological Systems of Concern; Important Connectivity Zones; etc), using the minimum criteria for an individual data layer.
Freshwater Integrity
Measure of freshwater habitat condition, typically including landscape variables and land use variables that are known to impact aquatic ecological systems.
Important Connectivity Zones
Data layer representing linear landscape paths for core habitats. WGA Landscape Integrity Workgroup created a west-wide data layer by identifying segments of centrality (or "flowlines") based on a human footprint/landscape condition dataset as a cost surface.
Riparian and Wetland Habitat Distribution
Areas that represent unique and/or sensitive environments and function to support animal and plant diversity with respect to wildlife objectives and connectivity.
Wildlife Corridors
Species - specific analysis of connectivity, typically including important movement areas.
Species of Economic and/or Recreational Importance
These may include game or sportfish species especially if habitat needs are not already covered by mapping "Species of Concern".
Terrestrial Species of Economic and/or Recreational Importance
Terrestrial game species especially if habitat needs are not already covered by mapping "Species of concern".
Aquatic Species of Economic and/or Recreational Importance
Sportfish, especially if habitat needs are not already covered by mapping "Species of Concern".
Protected Areas
Protected Areas data comes from the Protected Areas Database of the United States (PAD-US). The map displays this data in a variety of ways to expose different components of the database including the Gap Analysis Program (GAP) status, the owner, and the designation (e.g. wilderness, Area of Critical Environmental Concern, etc). Click here for more information on Protected Areas data.
Watershed and Sub-Watershed Boundaries
Watershed boundaries define the aerial extent of surface water drainage to a point and are important contextual information for the Crucial Habitat map. Hydrologic Unit levels 5 and 6 were obtained from the National Resources Conservation Services (NRCS) and are displayed on the Western Governors' CHAT. Click here for more information on the Watershed Boundary Dataset.
Lesser Prairie-Chicken Focal Areas and Connectivity Zones
These boundaries represent the current general range of the Lesser Prairie-Chicken (LEPC) and important habitat areas utilized in the LEPC Range-Wide management plan.

Users may cite the Crucial Habitat Assessment Tool and data set as follows:

State Wildlife Agencies of the Western United States. West-wide Crucial Habitat Data Set. Western Governors’ Crucial Habitat Assessment Tool: Mapping Fish and Wildlife Across the West. Western Governors’ Association. Published [Insert date data downloaded]. Accessed [Insert Date]. http://www.westgovchat.org