Field Notes
U.S. Fish & Wildlife Service
Field Notes Entry   
Chesapeake Bay Field Office Uses LiDAR to Identify Delmarva Fox Squirrel Habitat
Northeast Region, June 2, 2010
Print Friendly Version
Forest Habitat Classes Using LiDAR
Forest Habitat Classes Using LiDAR - Photo Credit: n/a
Sample Map of Forest Habitat Classes Identified
Sample Map of Forest Habitat Classes Identified - Photo Credit: n/a
Map of Potential Delmarva Fox Squirrel Habitat
Map of Potential Delmarva Fox Squirrel Habitat - Photo Credit: n/a

The Delmarva fox squirrel prefers mature stands of mixed pine/hardwood forest. Existing remote sensing data delineated dominant tree species but did not distinguish between young and mature forests. Thus, until recently, a widespread inventory of Delmarva fox squirrel habitat was not possible.


The Chesapeake Bay Field Office worked with a contractor and partners at Goddard Space Center and the Maryland Department of Natural Resources to develop a forest canopy height map using Light Detection and Ranging (LiDAR) data that could be used to identify suitable forest habitat for Delmarva fox squirrels.


LiDAR determines the height or elevation of objects on the ground using aerial-borne equipment. While it uses a laser light, it is similar to SONAR, and measures the time a beam  bounces off an object and returns to determine distance. The "first-return" of the laser data is produced as it bounces off the forest canopy; and the "last-return" is the ground elevation. The difference between these two measurements is a measure of canopy height. Since canopy height is clearly different between the general classes of mature forest, pole-timber and young regenerating stands, it can also be uses to distinguish mature forest.  


The final forest map shows six height classes. These height classes were compared to forest stands of known age. The three tallest height classes are roughly classified as saw timber, the fourth height class is approximately pole-sized timber, and the lowest two height classes are young stands of seedlings and saplings. 


Based on previous work, a model for Delmarva fox squirrel habitat was developed using the LiDAR data. Delmarva fox squirrel habitat was defined as the tallest two height classes (Habitat Class 1 and 3) and Habitat Class 5 if present with at least 20% of Habitat class 1 or 3.


The Chesapeake Bay Field Office tested this model at Blackwater National Wildlife Refuge.  Sites where Delmarva fox squirrels were present had significantly more LiDAR-defined tall, mature trees than sites where squirrels were absent. The LiDAR habitat model can now be used to map mature forest that is potentially suitable for Delmarva fox squirrels across the landscape.  Forest mapping has been completed for the eight Maryland counties where Delmarva fox squirrels occur.


For more information contact:

Cherry Keller



Contact Info: Kathryn Reshetiloff, 410-573-4582, kathryn_reshetiloff@fws.gov
Find a Field Notes Entry

Search by keyword

Search by State

Search by Region

US Fish and Wildlife Service footer