Abstract
Nest and hatchling fates of Snowy Plovers (Charadrius alexandrinus) was determined through frequent observations during the 2002-2006 nesting seasons. At the completion of nesting in 2005 and 2006, several characteristics of habitat were measured around the nest site. The same characteristics were measured at randomly chosen points along the beach to test for preferential selection of habitat characteristics in nest-site selection using a Mann-Whitney Utest. Productivity was estimated during both egg and hatchling stages using a combination of the Mayfield method and apparent success (# successful attempts divided by # observed attempts). Differences in beach traffic density were also documented between two nesting areas on the island. From 2002 through 2006 the number of breeding Snowy Plovers on Sanibel Island declined from a high of 15 pairs in 2004 to a low of 6 in 2006. An average replacement rate of .644 was not sufficient to support population stability or growth from 2003 through 2006. Both hatching success and fledging success varied among years and between nesting areas. The probability that a chick would survive to fledge was 2.7 times greater at the more heavily trafficked beach nesting area. Significant differences between some nest-site habitat characteristics and habitat measured at random points suggest preferential habitat selection. An increased percent cover of dead organic matter and proximity to the dune were shown to be important factors in nest-site selection. Other factors such as increased percent cover of large shell particles and increased beach slope while not significant in all tests, showed some signs of selection.
