OUTDATED Indicator V 2.0: Pine & Prairie: Pine and Prairie Birds
Dates
Release Date
2015-04-29
Summary
Pine and Prairie Birds This layer is an outdated version of one of the South Atlantic LCC indicators in the pine woodlands, savannas and prairies ecosystem. It is an index combining species distribution and census data for three pine and prairie bird species. This indicator was updated in Blueprint 2.1 to extend the Northern bobwhite and red-cockaded woodpecker data to new areas of the pine and prairie ecosystem map. Reason for Selection This species index represents the structure and function of pine ecosystems in the Southeast. Input Data The distribution of red-cockaded woodpecker ( Picoides borealis), Northern bobwhite ( Colinus virginianus), and Bachman's sparrow ( Aimophila aestivalis) are included in the index. Northern Bobwhite [...]
Summary
Pine and Prairie Birds
This layer is an outdated version of one of the South Atlantic LCC indicators in the pine woodlands, savannas and prairies ecosystem. It is an index combining species distribution and census data for three pine and prairie bird species. This indicator was updated in Blueprint 2.1 to extend the Northern bobwhite and red-cockaded woodpecker data to new areas of the pine and prairie ecosystem map.
Reason for Selection
This species index represents the structure and function of pine ecosystems in the Southeast.
Input Data
The distribution of red-cockaded woodpecker ( Picoides borealis), Northern bobwhite ( Colinus virginianus), and Bachman's sparrow ( Aimophila aestivalis) are included in the index.
Northern Bobwhite
To model the distribution of bobwhite, the National Bobwhite Technical Committee used an extensive series of initial and revision workshops, where a multitude of experts conducted a spatially explicit habitat ranking based on GIS data and local expert knowledge (The National Bobwhite Technical Committee 2011). Bobwhite habitat suitability was ranked from low to high; for our purposes, we used the highest ranking, "high," as a conservation target (i.e., 0/1).
Red-Cockaded Woodpecker (RCW)
RCW data were primarily obtained from NatureServe (2014) with cooperation from state Natural Heritage programs of Virginia, North Carolina, South Carolina, Georgia, Alabama, and Florida. Important supplemental data were supplied by Francis Marion National Forest in South Carolina and Tall Timbers Research Station in Florida. We removed records classified as "extirpated" and records with > 2 km of potential location error. Of the remaining locations, we used RCW data when the last recorded observation was 1990 or later. This long timeframe was necessary because private land surveys are often not repeated, Federal and state agreements with landowners may restrict data access, and there is often a substantial lag time for reporting monitoring data on public lands. Locations where RCWs were last observed from 1970-1989 were often noted as inactive nest cavities or had been surveyed later without finding evidence of RCWs. In contrast, post-1990 data were typically active clusters, although many had not been surveyed regularly. Since the extent of habitat was not always recorded, we also used the point locations, or plotted a point at the center of RCW polygons, and placed a 2 km radius buffer around each point. An 800 m buffer has been suggested and used for RCW locations (James et al. 2001, U.S. Fish and Wildlife Service 2003), but here, we wanted to extend this to account for location errors. We did not include RCW locations within the forested wetland ecosystem east of the Suffolk Scarp of North Carolina (i.e., pocosin habitat), as indicators were restricted to the historic range of the longleaf pine savanna.
Bachman's Sparrow
Bachman's sparrow locations were recorded in three distinct survey projects conducted by the North Carolina Wildlife Resources Commission (NCWRC) (n = 544; 2006-2013), Paul Tallie et al. (2015) (n = 99; 2012), and a Virginia Tech study in cooperation with the U.S. Marine Corp at Camp Lejeune (n = 84; 2010). Paul Taillie (NCWRC), Jeffrey Marcus (The Nature Conservancy), Scott Anderson (NCWRC), and John Carpenter (NCWRC) collected data and summarized existing data sources. Data were collected as part of species-specific point count surveys with call-backs, general point counts, and as incidental observations. Points within 250 m of another presence location were removed from the dataset. Fires were quantified from the LANDFIRE program (also known as the Landscape Fire and Resource Management Planning Tools). The National Land Cover Database (NLCD) classifications of evergreen forest and a combined layer of shrub/scrub and grassland/herbaceous depicted coarse land cover classes. Tree canopy cover was quantified with NLCD. All of these variables were calculated with 3x3 and 9x9 neighborhood statistics. Connectivity was quantified using local connectedness from The Nature Conservancy's Southeastern Terrestrial Resilience dataset (Anderson et al. 2014). This connectivity measure emphasized fragmentation caused by agriculture and urban development. After initial model development, we calculated the amount of habitat within a 5 km radius and included this result in the model.
A resource selection function (RSF) modeling approach was used (Boyce et al. 2002) with pseudo-absences dispersed throughout the survey extent; row crop agriculture and urban classifications (NLCD land cover classes 21-24) were excluded. A logistic regression compared Bachman's sparrow presence with pseudo-absence points. This compared Bachman's sparrow habitat use vs. availability. As results of logistic regression are not directly relevant to assessing a resource selection function, data were divided into training data (60%) and validation data (40%). RSFs are relative measures of habitat use, but we wanted to determine a threshold for estimating presence/absence. Similar to other studies (Wilson et al. 2013, Fedy et al. 2014) we determined the optimal classification threshold with the training data, and applied it to the validation data. We were primarily interested in how well the model performed in predicting presence and the proportion of area predicted.
The results showed canopy cover, evergreen land cover, canopy cover SD, fires, and connectedness were related to Bachman's sparrow. After projection of these variables, we also discovered an association with habitat within a 5 km radius of a cell. The confusion matrix of the validation results showed 90% classification accuracy. The RSF model predicted 9% of North Carolina as Bachman's sparrow "present" and captured 87% of known Bachman's sparrow presence locations in North Carolina.
Questions about Bachman's sparrow modeling may be directed to Bradley Pickens, bapicken@ncsu.edu.
Mapping Steps
Indicators used in Blueprint 2.0 were initially computed, or in the case of existing data, were resampled to 1 ha spatial resolution using the nearest neighbor method. For computational reasons, we then used the Spatial Analyst aggregate function to rescale the resolution to 200 m. The aggregate function avoided loss of detail by taking the maximum value of each cell in the conversion (e.g., species presence).
Cumulative Pine Bird Index
The final Pine Bird Index was derived by summing the number of species in each 200 m cell.
The indicator is classified as follows:
0 = Pine index birds absent (low)
1 = 1 pine index bird present
2 = 2 pine index birds present
3 = 3 pine index birds present (Bachman's sparrow, bobwhite quail, and red-cockaded woodpecker) (high)
Known Issues and Data Limitations
Data are not to be interpreted for legal or regulatory actions. The indicators are intended for conservation planning purposes and to depict the ecological condition of the landscape. The Pine Bird Index will be improved in the future by addressing the distribution of each species as noted below.
For Bachman's sparrow, the model is trained and validated with North Carolina data and is extrapolated to the whole South Atlantic LCC. More data is needed to validate this extrapolation. However, habitat variables were chosen with specific reference to Bachman's sparrow ecology. Fires, canopy cover, evergreen trees, and fragmentation are all known to be factors affecting Bachman's sparrow throughout the Southeast. Definitive absence data would be helpful for verifying the presence/absence threshold chosen here. The 90% accuracy of the model in North Carolina shows that the model is of high quality, but 10% error is still expected. The data should not be treated as a complete census.
For RCWs, data is near census level, but data from private lands may be limited in a few localities. Some locations post-1990 could use a more recent verification. The Northern bobwhite model does not provide quantitative abundance estimates. The bobwhite model is based on expert opinion and needs to be validated, or possibly improved, with quantitative survey data.
Defining the Spatial Extent of Ecosystems
This indicator has been clipped to the pine and prairie ecosystem. Visit the Blueprint 2.0 ecosystem maps page for an explanation of how each ecosystem’s spatial extent is defined.
Known Issues
-- The model only incorporated Bachman's sparrow presence data from North Carolina and used it to predict the indicator for the whole South Atlantic geography. More data is needed to validate this extrapolation. However, habitat variables were chosen with specific reference to Bachman's sparrow ecology. Fires, canopy cover, evergreen trees, and fragmentation are all known to be factors affecting Bachman's sparrow throughout the Southeast. Definitive absence data would be helpful for verifying the presence/absence threshold chosen here. The 90% accuracy of the model in North Carolina shows that the model is of high quality, but 10% error is still expected. The data should not be treated as a complete census.
-- For RCWs, data is near census level, but data from private lands may be limited in a few localities. Some locations post-1990 could use a more recent verification. Additionally, some data on RCW locations post-1990 are likely still missing from this indicator.
-- The Northern bobwhite model does not provide quantitative abundance estimates. The bobwhite model is based on expert opinion and likely has issues in places where consulted experts had less experience.
Indicator Overview
The South Atlantic ecosystem indicators serve as the South Atlantic LCC's metrics of success and drive the identification of priority areas for shared action in the Conservation Blueprint. To learn more about the indicators and how they are being used, please visit the indicator page. Check out the Blueprint page for more information on the development of the Blueprint, a living spatial plan to conserve our natural and cultural resources.
Literature Cited
Anderson, M.G., A. Barnett, M. Clark, C. Ferree, A. Olivero Sheldon, and J., Prince. 2014. Resilient Sites for Terrestrial Conservation in the Southeast Region. The Nature Conservancy, Eastern Conservation Science. 127 pp.
Boyce, M. S., P. R. Vernier, S. E. Nielsen, and F. K. A. Schmiegelow. 2002. Evaluating resource selection functions. Ecological Modelling 157:281-300.
Fedy, B. C., K. E. Doherty, C. L. Aldridge, M. O'Donnell, J. L. Beck, B. Bedrosian, D. Gummer, M. J. Holloran, G. D. Johnson, N. W. Kaczor, C. P. Kirol, C. A. Mandich, D. Marshall, G. McKee, C. Olson, A. C. Pratt, C. C. Swanson, and B. L. Walker. 2014. Habitat Prioritization Across Large Landscapes, Multiple Seasons, and Novel Areas: An Example Using Greater Sage-Grouse in Wyoming. Wildlife Monographs:1-39.
James, F. C., C. A. Hess, B. C. Kicklighter, and R. A. Thum. 2001. Ecosystem management and the niche gestalt of the red-cockaded woodpecker in longleaf pine forests. Ecological Applications 11:854-870.
NatureServe. 2014. NatureServe Central Databases. Arlington, Virginia. U.S.A.
Taillie, P. J., M. N. Peterson, and C. E. Moorman. 2015. The relative importance of multiscale factors in the distribution of Bachman's Sparrow and the implications for ecosystem conservation. The Condor 117:137-146.
The National Bobwhite Technical Committee. 2011. The National Bobwhite Conservation Initiative: a range-wide plan for recovering bobwhites. National Bobwhite Technical Committee Technical Publication, ver. 2.0 In W. E. Palmer, T.M. Terhune, and D.F. McKenzie [ed.], Knoxville, TN.
U.S. Fish and Wildlife Service. 2003. Recovery plan for the red-cockaded woodpecker ( Picoides borealis): second revision, U.S. Fish and Wildlife Service, Atlanta, GA.
Wilson, J. W., J. O. Sexton, R. T. Jobe, and N. M. Haddad. 2013. The relative contribution of terrain, land cover, and vegetation structure indices to species distribution models. Biological Conservation 164:170-176.
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Rights
<a rel="license" href="http://creativecommons.org/licenses/by/4.0/"><img alt="Creative Commons License" style="border-width:0" src="https://i.creativecommons.org/l/by/4.0/88x31.png" /></a><br />This work is licensed under a <a rel="license" href="http://creativecommons.org/licenses/by/4.0/">Creative Commons Attribution 4.0 International License.</a> The indicator data and maps provided are only intended for use as a reference tool for landscape-level conservation planning efforts.