Bird density and marine mammal counts based on 3000 meter bins in southern California, 1999-2002

Tracklines and associated observations were mapped and analyzed using ArcMap (ESRI, Redlands, CA). GPS data were recorded in NAD27 map datum and projected to an USGS...轨迹线（Tracklines）及相关观测数据已通过ArcMap（ESRI，加利福尼亚州雷德兰兹市）完成制图与分析。所记录的GPS数据采用NAD27大地基准面（NAD27 map datum），并投影至美国地质调查局（United States Geological Survey, USGS）……