title: Mapping migratory bird prevalence using remote sensing data fusion.
abstract: BACKGROUND
  Improved maps of species distributions are important for effective management of wildlife under increasing anthropogenic pressures. Recent advances in lidar and radar remote sensing have shown considerable potential for mapping forest structure and habitat characteristics across landscapes. However, their relative efficacies and integrated use in habitat mapping remain largely unexplored. We evaluated the use of lidar, radar and multispectral remote sensing data in predicting multi-year bird detections or prevalence for 8 migratory songbird species in the unfragmented temperate deciduous forests of New Hampshire, USA.
  
  
  RESULTS
  A set of 104 predictor variables describing vegetation vertical structure and variability from lidar, phenology from multispectral data and backscatter properties from radar data were derived. We tested the accuracies of these variables in predicting prevalence using Random Forests regression models. All data sets showed more than 30% predictive power with radar models having the lowest and multi-sensor synergy ("fusion") models having highest accuracies. Fusion explained between 54% and 75% variance in prevalence for all the birds considered. Stem density from discrete return lidar and phenology from multispectral data were among the best predictors. Further analysis revealed different relationships between the remote sensing metrics and bird prevalence. Spatial maps of prevalence were consistent with known habitat preferences for the bird species.
  
  
  CONCLUSIONS
  Our results highlight the potential of integrating multiple remote sensing data sets using machine-learning methods to improve habitat mapping. Multi-dimensional habitat structure maps such as those generated from this study can significantly advance forest management and ecological research by facilitating fine-scale studies at both stand and landscape level.
authors.affiliation: College Park, University of Maryland, Maryland, United States of America. aswatan@umd.edu
authors.forename: Anu
authors.initials: A
authors.lastname: Swatantran
authors.forename: Ralph
authors.initials: R
authors.lastname: Dubayah
authors.forename: Scott
authors.initials: S
authors.lastname: Goetz
authors.forename: Michelle
authors.initials: M
authors.lastname: Hofton
authors.forename: Matthew G
authors.initials: MG
authors.lastname: Betts
authors.forename: Mindy
authors.initials: M
authors.lastname: Sun
authors.forename: Marc
authors.initials: M
authors.lastname: Simard
authors.forename: Richard
authors.initials: R
authors.lastname: Holmes
mesh_terms: D025041:Animal Migration; D000818:Animals; D001185:Artificial Intelligence; D017753:Ecosystem; D011825:Radar; D020308:Songbirds; D013223:Statistics as Topic / Q000379:methods*; D013997:Time Factors; D014197:Trees