West Coastal Plain & Ouachitas Forested Wetland Birds

This indicator is an index of habitat suitability for five forested wetland bird species (Acadian flycatcher, Kentucky warbler, yellow-throated warbler, prothonotary warbler, red-shouldered hawk) within bottomland hardwood forests and riparian areas in the West Gulf Coastal Plain and Ouachitas Bird Conservation Region. It uses metrics like patch size, dispersal distance, distance to water, and more to assess the potential for habitat to support sustainable populations of these birds. This indicator originates from the Lower Mississippi Valley Joint Venture’s forested wetland decision support model for the West Gulf Coastal Plain and Ouachitas region.

Reason for Selection

Some factors related to patch size and landscape composition that are important to forested wetland species are not well-represented by other indicators. Forested wetlands and associated bottomland hardwoods represent a unique and imperiled habitat in the region that supports birds and many other wildlife species. Maintaining the structure and integrity of these forested wetlands has conservation implications that extend well beyond the West Gulf Coastal Plain and Ouachitas subregion due to their importance for birds migrating to and from Mexico, the West Indies, and Central and South America. This indicator also promotes consistency with the forest management and protection priorities of the Lower Mississippi Valley Joint Venture.

Input Data

• WGCPO Forested Wetland Decision Support Model: Detailed description of methods are available under “Decision support model” in the West Gulf Coastal Plain and Ouachitas Forested Wetland Plan, Version 1.0.

  This decision support model first characterized the landscape that was available to each forested wetland bird umbrella species for breeding. It identified landscapes with enough potentially suitable habitat to support a minimum viable population based on the amount of woody wetland landcover, minimum viable population size and area requirements, and natal dispersal distance. Then, it prioritized that potential breeding landscape based on each species’ unique habitat needs: distance to water, percent forest cover, flood tolerance and flood preference, and presence of bald cypress-tupelo floodplain forest. Lastly, it combined each species-specific habitat suitability model into the final composite index used in this indicator.

• Base Blueprint 2022 extent
• Base Blueprint 2022 subregions

Mapping Steps

• Reproject the WGCPO Forested Wetland Decision Support Model source data to NAD 1983 Contiguous USA Albers (EPSG 5070).
• Reclassify the source data as seen in the legend below. The WGCPO Forested Wetland Decision Support Model layer from the LMVJV has values ranging from 0 to 0.933365. We classified the data into five groups based on percentile priority within the West Gulf Coastal Plain and Ouachitas regional boundary for the six umbrella species listed above (Acadian flycatcher, Kentucky warbler, yellow-throated warbler, prothonotary warbler, and red-shouldered hawk).
• Change 0 values to NoData.
• Clip to the ‘West Gulf Coastal Plain’ and ‘Ouachita’ subregions, where this indicator was used in Zonation. The source data also covers some areas in the ‘Gulf Coastal Prairies’ and ‘Mississippi Alluvial Valley’ subregions. We didn’t include data in those subregions due to an oversight in which indicators were used for the Blueprint priorities in those subregions.
• As a final step, clip to the spatial extent of Base Blueprint 2022.

Note: For more details on the mapping steps, code used to create this layer is available in the Southeast Blueprint 2022 Data Download under BlueprintInputs > BaseBlueprint2022 > 6_Code.

Final Indicator Values

Indicator values are assigned as follows:

• 5 = High habitat suitability for forested wetland bird umbrella species (Acadian flycatcher, Kentucky warbler, yellow-throated warbler, prothonotary warbler, red-shouldered hawk) (score >80)
• 4 = Medium-high habitat suitability (score >60-80)
• 3 = Medium habitat suitability (score >40-60)
• 2 = Medium-low habitat suitability (score >20-40)
• 1 = Low habitat suitability for forested wetland bird umbrella species (score 0-20)

Known Issues

• The indicator does not account for important components of stand structure that impact habitat quality for these species. Key factors include: a) large tree diameter (>23 cm dbh), b) density of large trees (>40 trees >50 dbh/ha), c) low tree density (250-300/ha), d) mid-story cover (open), e) understory cover (open), f) understory cover (dense), g) moderate to well-developed canopy (60–70%), and h) small cavities (< 10 inch diameter) or snag density of 5 snags/ha.
• The indicator does not account for variation in water quality.
• While the indicator source data extends into some areas within the Gulf Coastal Prairie and Mississippi Alluvial Valley subregions, those areas are not included in the indicator because they were not used in the Blueprint priorities for those subregions. We didn’t include those pixels due to an oversight in which indicators were used for the Blueprint priorities in those subregions.

Disclaimer: Comparing with Older Indicator Versions

There are numerous problems with using Southeast Blueprint indicators for change analysis. Please consult Blueprint staff if you would like to do this (email hilary_morris@fws.gov).

Literature Cited

West Gulf Coastal Plains and Ouchitas Forested Wetland Landbird Plan. 2017. [https://static1.squarespace.com/static/5bb3865d2727be6f94acf2fc/t/5bfc99b221c67c2cdd60ab54/1543281078237/WGCPO_BLH_Riparian_Plan_Oct2017.pdf].