| Food is an important factor influencing the distribution and abundance of shorebirds. The Western snowy plover (Charadrius nivosus nivosus) is a federally threatened shorebird that breeds and winters along the Pacific Coast of the United States and Mexico. In Northern California, talitrid amphipods are the main prey of snowy plovers. To better understand this relationship between amphipods and snowy plovers, we quantified amphipod abundance and distribution in suitable plover habitat in Humboldt County, CA. In July and August, we conducted systematic-random ground plots within the wrack, left by the previous night's high tide, to quantify amphipod abundance across beach sites. We also categorized invertebrate densities by collecting core samples over the course of a year at three beach sites where plovers breed and winter. Collated ground plots showed significantly different mean amphipod abundances across beach sites. Core samples also suggest variation in amphipod abundance across sites as well as a seasonal variation within each site. Understanding the distribution and abundance of amphipods will help managers determine how prey availability may influence snowy plover distribution. |