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THE WILSON JOURNAL OF ORNITHOLOGY • Vol. 123. No. 4. December 2011 
The Wilson Journal of Ornithology 123(4):814—819. 2011 
Breeding Success and Nest Site Selection by a Caribbean Population of 
Wilson’s Plovers 
Adam C. Brown 1 - 2 and Kevin Brindock 1 
ABSTRACT.—We report breeding success of Wil¬ 
son’s Plovers (Charadrius wilsonia ) on St. Martin in the 
Lesser Antilles during 2004. We located 35 nests among 
six wetlands and apparent nest success was 31.\%. Nest 
initiation on St. Martin was earlier than in the United 
States and breeding success was higher earlier in the 
season than later in the season. There were two distinct 
peaks in nest initiation: the second peak coincided with 
peak fledging of chicks from the first nest initiation. 
Nests on St. Martin were associated with bare ground 
and were much closer together than in previous studies 
reported elsewhere. Ten nests were predated by feral 
dogs (Canis lupus familiaris) and three nests were 
crushed by vehicles. Received 12 December 20/0. 
Accepted 15 April 2011. 
Wilson's Plover (Charadrius wilsonia ) is 
distributed along coastal habitats extending from 
North America to South America including the 
West Indies (Corbat and Bergstrom 2000). 
Populations of the Caribbean race (C. w. cinna- 
mominus ) occur in the Bahamas. Greater Antilles, 
Virgin Islands, and throughout the Lesser Antilles 
(Hoogerwerf 1977. Collazo et al. 1995. Raffaele 
et al. 1998, Smith and Smith 1999). The most 
recent global population estimate of Wilson’s 
Plover is 6,000 individuals: however, this number 
is tenuous as the estimate was provided with a low 
level of confidence (Brown ct al. 2001). Wilson's 
Plovers are listed as a Species of High Concern in 
the U.S. Shorebird Conservation Plan due to a low 
population estimate (Brown et al. 2001). The 
primary threat to Wilson's Plovers in the United 
States is habitat loss resulting from development 
(Corbat and Bergstrom 2000). 
There has been little research on Wilson's 
Plovers in the West Indies; thus, there are 
currently no population estimates for the region 
and breeding ecology in this area is poorly 
understood. The absence of population estimates 
and data on breeding ecology of Wilson’s Plovers 
'Environmental Protection in the Caribbean. 200 Dr 
33404 Khlg Jf ' B ° UleVard * Kiviera Bcach ' FL 
-Corresponding author; e-mail: abrown@epicislands.org 
in the Caribbean, highlight the need for further 
study to understand the status of this species in the 
region and to guide conservation efforts to 
maintain this population. We studied a breeding 
population of Wilson’s Plovers on St. Martin. 
Lesser Antilles in 2004. Our objectives were to: 
(I) investigate attributes of the plover’s nesting 
ecology and, (2) factors affecting breeding 
success. 
METHODS 
Study Area.— St. Martin. Lesser Antilles 
(18 03' N. 63 03' W; 100 knr) includes several 
breeding sites used by Wilson’s Plovers, making it 
a suitable study area to examine their breeding 
ecology. The island includes 21 wetland sites 
providing suitable nesting habitat for this plover, 
Sites ranged in size from 0.136 to 2.2626 ha, 
Every wetland was surrounded by vegetation 
comprised mainly of red mangroves (Rhizophoru 
mangle), black mangroves (Avicetmia geminam). 
white mangroves (Laguncularia racemosa), but¬ 
tonwood (Conocarpus erectus), and sea-grape 
(Coccoloba uvifera). There was sparse mangrove 
vegetation scattered throughout the wetland. 1 ; as 
well. Each wetland was surveyed from multiple 
observation points, assuring the shoreline of each 
wetland was observed in its entirety. 
Nest Observations .—We surveyed all sites (n = 
21) on St. Martin from 1 January through 30 July 
2004. every 5 days using binoculars and spotting 
scopes to detect breeding shorebirds (Fig. D- 
Once a Wilson's Plover was detected, observers 
recorded the bird's behavior, including that 
suggestive of active nesting, such as birds flying 
back-and-forth towards a specific spot, males 
chasing other birds in the hunched-over territorial, 
mock-brooding, or broken-wing displays (Berg¬ 
strom 1988). We then approached the area when: 
the bird was observed and searched all adjacent 
suitable habitats in a grid-like pattern for a nest 
scrape. Plover tracks were often followed to help 
observers locate the nest scrape. Observers 
estimated and recorded the stage of nesting 
