Reproductive Success of the American Oystercatcher (Haematopus palliatus) in Texas

Abstract

The American Oystercatcher (Haematopus palliatus) is listed as a Species of High Concern in the United States Shorebird Conservation Plan due to a small population size and threats during its annual cycle. Previous studies of the American Oystercatcher have focused on Atlantic Coast populations; however, little is known about the reproductive success of the western Gulf Coast population. The objective of this study was to determine nest and brood survival of American Oystercatchers in Texas. A total of 337 nests and 121 broods were monitored on the Texas Gulf Coast during 2011-2013. The top model for nest survival in Program MARK included a linear decline in survival across the nesting season and as nests aged. Survival also declined as island size and foraging habitat near the nest site increased. The probability of a nest surviving from mean initiation date to hatching was 0.384 (95% CI = 0.317, 0.451). The top model for brood survival included a linear decline in survival across the season and an increase in survival as broods aged. Brood survival also varied among years and coastal region. The probability of a brood surviving from mean hatch date to 35 days after hatch ranged from 0.397 (95% CI = 0.204, 0.578) in 2013 to 0.887 (95% CI = 0.673, 0.964) in 2011 across all regions. Known causes of nest and brood loss included beach overwash, depredation, and starvation. This study provides the first estimates of nest and brood survival of the American Oystercatcher along the western Gulf Coast. The additional insight into patterns of nest and brood survival in this species will be useful for future conservation planning efforts that target breeding American Oystercatchers. Known causes of nest and brood loss included beach overwash, depredation, and starvation. This study provides the first estimates of nest and brood survival of the American Oystercatcher along the western Gulf Coast. The additional insight into patterns of nest and brood survival in this species will be useful for future conservation planning efforts that target breeding American Oystercatchers. Keywords

Implications of spring water levels on the production of American white pelicans nesting at marsh lake, Minnesota

“…Our observations from nest cameras and nest survival rates support a similar hypothesis for American white pelican nesting at Marsh Lake. In other colony‐nesting birds, the benefits of island nesting (Koczur et al , Anteau et al ) or nesting farther from mainland areas (Skorka et al ) are consistent with our findings for American white pelicans at Marsh Lake.…”

Drivers of the breeding success of American Oystercatchers ( Haematopus palliatus frazari ) at a critical site in Sinaloa, Mexico

“…Nests in this habitat were located at intermediate distances from the high tide line (< 30 m), suggesting a reduced risk of flooding as well as access to nearby foraging areas. Several studies of American Oystercatchers have revealed that those nesting on barrier islands with adjacent nesting and foraging territories have greater reproductive success (Koczur et al 2014). The greater breeding success of American Oystercatchers in the mixed marsh and dune habitat in our study may have been due to adults having more time to care for nests and broods than those in other habitats.…”

“…On the Atlantic coast, clutch sizes and breeding productivity varied from 2.3 to 2.7 eggs and 0.20 to 0.75 fledglings per pair, respectively (Wilke et al 2005, Traut et al 2006, Schulte and Simons 2015). Habitat suitability may also influence parental care by American Oystercatchers because of differences in food availability and the subsequent effects on breeding success (Koczur et al 2014, Schulte and Simons 2015). Moreover, adults that make shorter foraging trips defend and care for nests and chicks more than adults that travel longer distances to feed (Nol 1989, Koczur et al 2014).…”

“…Habitat suitability may also influence parental care by American Oystercatchers because of differences in food availability and the subsequent effects on breeding success (Koczur et al 2014, Schulte and Simons 2015). Moreover, adults that make shorter foraging trips defend and care for nests and chicks more than adults that travel longer distances to feed (Nol 1989, Koczur et al 2014). Additionally, individuals in territories with adjacent nesting and foraging areas (< 50 m) have been found to have greater hatching success (Nol 1989, Koczur et al 2014).…”

Nest survival in year‐round breeding tropical red‐capped larks Calandrella cinerea increases with higher nest abundance but decreases with higher invertebrate availability and rainfall

“…Among 2 the factors affecting nest survival, nest predation has been shown to be the major cause of nest failure in most bird species (Ricklefs 1969, França et al 2016. For many species, nest survival varies over time (Grant et al 2005, Koczur et al 2014, Berkunsky et al 2016, França et al 2016, Polak 2016). Yet, studies evaluating the proximate factors involved in explaining nest survival, such as food, weather, and breeding activities of conspecifics, have mostly been carried out in temperate areas and rarely in the tropics (Thomson 1950, Martin 1987, Stutchbury and Morton 2008.…”