On using digital maps to assess wildlife habitat

Abstract

Currently, there are no accepted standards in the wildlife literature for reporting details of digital map products used to assess habitat. Digital maps developed from remotely sensed images vary widely in how they represent landscapes. Consequently, certain characteristics of remotely sensed data need to be addressed when reporting results obtained from digital maps to allow the reader to understand the strengths and limitations of the map product(s) used. We reviewed 44 articles published in The Journal of Wildlife Management between 2000–2002 that used digital maps developed from aerial photography or satellite imagery to assess wildlife habitat and summarized which map parameters were reported and which were overlooked. We found that most papers failed to report important details about digital map products used to assess wildlife habitat. To provide an example of variability in digital map products, we compared digital maps developed from aerial photographs and satellite imagery that we used to measure vegetation characteristics within northern spotted owl (Strix occidentalis caurina) territories as part of a region-wide demographic study. We found that the 2 map types produced quite different measurements of vegetation for the same area. Many differences that we observed are inherent to aerial photo and satellite maps in general. We provide a suggested list of map details to be reported when using digital vegetation maps to quantify wildlife habitat.