Age-related movements and distribution of western snowy plover (Charadrius alexandrinus nivosus) broods

I examined age-related movements and patterns of space use of individual adult Western Snowy Plovers (Charadrius alexandrinus nivosus) tending broods on Clam Beach, Humboldt County, CA from 2001-2006. In general, chicks made abrupt, 500-1000 m movements away from their nests in the first three days of life, and thereafter showed a gradual decrease in distance moved between consecutive days. Both daily distance from nest and home range size continued to significantly increase until chicks reached the age of 14 d. The distribution of broods along Clam Beach was consistent among the six years of the study. Particular sections of the beach were regularly used more highly than others each year by adult plovers rearing broods. I investigated the relationships between brood distribution and habitat characteristics in 2005 and 2006, using an information-theoretic approach. The distribution of males and their broods was most strongly positively associated with the distribution of nests in both years. Fledging success doubled in an area of the beach during four years when a refuge from human disturbance for breeding plovers was delineated with a symbolic fence, compared to the previous three years when the fence was not present. Human activity is one of three main limiting factors that has led to a significant decline in this federally listed threatened species. Creating areas of refuge from human activity may be an effective management action, helping to increase fledging success in areas with high human use, such as Clam Beach.