Monitoring Shorebird Habitat using Photogrammetry: The case of Western Snowy Plover at Coal Oil Point Reserve, Santa Barbara, California

Abstract

The goal of this study was to determine how digital photogrammetry can be used to describe and monitor shorebird habitat. Methods previously used for monitoring beach erosion were applied to shorebird habitat, concentrating on the requirements of Western Snowy Plovers. How the physical habitat of Western Snowy Plovers has changed over time was investigated at Sand Beach, which is part of Coal Oil Point Reserve in Santa Barbara, California, from 1928 to 2004, using width, area, and elevation data gathered from a series of aerial photographs. Single georeferenced photographs were used to measure width at regular intervals and area for each year a photo was available. Georeferenced aerial photographs can be used to obtain accurate measurements of beach area and width. Orthorectification is not necessary if photos can be georeferenced with minimal error. Sands Beach was found to be increasing in area. This was due mainly to the retreat of the vegetation line as the mouth of Devereux Slough shifted in 1992 rather than an accumulation of sand on the beach.

Keywords:

• beach
• California
• Charadrius alexandrinus nivosus
• Santa Barbara
• shorebird
• shoreline change
• Western Snowy Plover