Haematopus Palliatus Research Articles

First Case of Double Brooding in American Oystercatchers (Haematopus palliatus) in North America

First Case of Double Brooding in American Oystercatchers (Haematopus palliatus) in North America

Foraging Repertoire of American Oystercatcher (Haematopus palliatus) in Two Different Habitats in an Important South American Wetland

Foraging Repertoire of American Oystercatcher (Haematopus palliatus) in Two Different Habitats in an Important South American Wetland

Alert and flight initiation distances of Chilean Flamingo and American Oystercatcher to anthropogenic stimuli in a stopover site

ABSTRACT Tourism provides benefits, such as economic incentives, increasing support for conservation. However, it can also evoke responses in wildlife and be analogous to predation risk. As tourism increases, adequate planning and management is necessary. Chilean Flamingos (Phoenicopterus chilensis) and American Oystercatchers (Haematopus palliatus) were exposed to four stimuli (single walker, group of walkers, car, and kayak) in a stopover site to determine their response and estimate minimal approach distances, controlling the effect of potentially influential factors. Flight initiation distance and the distance at which birds change its posture or orientation to monitor an approaching threat (alert distance) were identified as response distances. Kayaks and cars allowed closer approaches than single walkers and groups of walkers for both species. The Chilean Flamingo exhibited responses to approaching stimuli at longer distances compared with oystercatchers. Potential factors (starting distance, month, season, initial behavior, and wind speed) including large variations among individuals, and influenced bird responses. To reduce the effects of tourists on bird behavior in an important stopover site, the minimal approach distance can be set at 80 m for the American Oystercatcher on the beach and 240 m for the Chilean Flamingo when walking and 207 m when kayaking in the estuary.

Isolation and Identification of Non-O1/Non-O139 Vibrio cholerae in Wild Birds Inhabiting Wetlands in Metropolitan Lima, Peru.

During a survey in wetlands from southern Lima, Peru, two non-O1/non-O139 Vibrio cholerae isolates were obtained from samples collected from an American Oystercatcher (Haematopus palliatus) and a Wren-like Rushbird (Phleocryptes melanops). Vibrio cholerae was identified by amplification and sequencing of 16S rRNA, differentially grown on CHROMagar Vibrio media, and confirmed by ompW amplification. Isolates were confirmed to be non-O1/non-O139 serotypes and to lack the ctxA gene as inferred using PCR. Susceptibility to eight antimicrobial agents was assessed, with one isolate being resistant to azithromycin, doxycycline, tetracycline, and furazolidone. Our results indicate the utility of surveillance for V. cholerae in wetlands in the metropolitan Lima area.

Specialist shorebird respond to prey and habitat availability through trophic plasticity

Spatiotemporal variations in food availability represent a challenge to the persistence of specialist species. The American oystercatcher (Haematopus palliatus) is a shorebird regarded as a bivalve specialist, although foraging habitats and prey species may vary along its distribution. Here, we studied American oystercatcher breeding in sites with variable landscapes to test the effect of temporal and spatial variations in food availability and dietary aspects. Between 2017 and 2021, we sampled oystercatchers (n = 100) and macroinvertebrates at the mesolitoral zone in five foraging areas in southern Brazil, three composed by sand and rock substrates (mixed), and two by sandy beach only. We obtained biological samples from oystercatchers and macroinvertebrates for carbon (δ13C) and nitrogen (δ15N) stable isotope analysis. In addition, we carried out systematic sampling of macroinvertebrates in sandy beaches at foraging areas to assess prey availability. Main findings showed the oystercatcher diet to be influenced both by the heterogeneity of foraging habitats and temporal fluctuations in availability of food resources. Bivalves contributed ∼60% to the diet of oystercatchers, but differences in the preferred bivalve species were detected among areas. In sites with mixed substrates, oystercatchers had a wider isotopic niche, suggesting habitat heterogeneity induced a more varied diet. Finally, we also observed interannual variation in the diet that may be associated with variation in macroinvertebrate availability on sandy beaches, especially for non-bivalve prey. Therefore, both temporal variations in food availability and foraging habitat heterogeneity seem to shape the foraging ecology of oystercatchers in the coastal zone, evidencing trophic plasticity in this specialist shorebird.

Shorebird Monitoring Using Spatially Explicit Occupancy and Abundance

Loss of habitat and human disturbance are major factors in the worldwide decline of shorebird populations, including that of the threatened migratory piping plover (Charadrius melodus). From 2013 to 2018, we conducted land-based surveys of the shorebird community every other week during the peak piping plover season (September to March). We assessed the ability of a thin plate spline occupancy model to identify hotspot locations on Whiskey Island, Louisiana, for the piping plover and four additional shorebird species (Wilson’s plover (Charadrius wilsonia), snowy plover (Charadrius nivosus), American oystercatcher (Haematopus palliatus), and red knot (Calidris canutus)). By fitting single-species occupancy models with geographic thin plate spline parameters, hotspot priority regions for conserving piping plovers and the multispecies shorebird assemblage were identified on the island. The occupancy environmental covariate, distance to the coastline, was weakly fitting, where the spatially explicit models were heavily dependent on the spatial spline parameter for distribution estimation. Additionally, the detectability parameters for Julian date and tide stage affected model estimations, resulting in seemingly inflated estimates compared to assuming perfect detection. The models predicted species distributions, biodiversity, high-use habitats for conservation, and multispecies conservation areas using a thin-plate spline for spatially explicit estimation without significant landscape variables, demonstrating the applicability of this modeling approach for defining areas on a landscape that are more heavily used by a species or multiple species.

Decline in annual survival of American oystercatchers wintering in Florida linked to extreme high tides

AbstractThe projected effects of climate change include an increase in the frequency and intensity of storm events and sea‐level rise, which can erode and degrade coastal habitats and affect coastal‐dependent species. The American oystercatcher (Haematopus palliatus) is a shorebird that is dependent on low‐lying coastal habitats for breeding and wintering and is particularly vulnerable to the effects of climate change and sea‐level rise. We investigated the degree to which changes in duration of flooding of roosts affected annual survival of individuals in a large wintering population of oystercatchers on the Nature Coast of Florida, USA. We used 12 years (2007–2018) of mark‐resight data from a large‐scale monitoring effort that included winter resights on Florida's Nature Coast to model the annual survival and site fidelity of sub‐adult and adult birds. High‐tide roosts are limited in number and are a potential population‐limiting factor for wintering oystercatchers. We assessed the effect of roost inundation on survival and site fidelity by incorporating the number of hours roosts were at risk of inundation during extreme higher high tide events each winter. We documented a 7.3% decline in annual survival, from 0.96 to 0.89, over the study period, and survival rates did not differ between age stages. The decline was associated with an increase in the duration of extreme higher high tides, which had a negative effect (β = −0.003; 95% CI = −0.006 to −0.001) on survival. Site fidelity varied across the study period and among age stages, with lower rates in sub‐adults (0.85; 95% CI = 0.80–0.89) than in adults (0.94; 95% CI = 0.89–0.97). The duration of nest and roost inundation are among the greatest threats to oystercatcher populations, and high‐tide roosts are an important habitat component for wintering populations on the Nature Coast. Sea‐level rise is predicted to increase, which will contribute to the increasing inundation duration of coastal habitats. Our results underscore the importance of conservation and restoration of important wintering habitats to mitigate threats to the population viability of oystercatchers in Florida and throughout their range.

Factors Limiting Reproductive Success of American Oystercatchers (Haematopus palliatus) in Florida's Southern Big Bend Region

Florida's Big Bend region hosts the second largest concentration of breeding American Oystercatchers in the state, but reproductive success is low. Nest site characteristics and predation were examined to determine their influence on survival of nests and broods at two areas in the southern Big Bend (Cedar Key and Barge Canal). The probability of a nest surviving in Cedar Key was low (x̄ = 0.25, CI = 0.13–0.41) and limited by nest overwash (46% of known nest attempts); survival of nests at Barge Canal was much higher (x̄ = 0.45, CI = 0.31–0.58). However, 40% of chicks that survived to fledge (35 days) at Barge Canal died before reaching independence (60 days). Raccoon presence and hatch date were negatively correlated with brood survival at Barge Canal. Finally, chicks at Barge Canal weighed less and were smaller compared to chicks at an Atlantic Coast site, which may be related to low abundance of live oysters within 100 m of their nest sites. Efforts to enhance oystercatcher reproductive success may require different approaches for each site: habitat restoration to increase elevation of nest sites in Cedar Key and reduction of predators at Barge Canal.

Contrasting long-term population trends of beach-nesting shorebirds under shared environmental pressures

Identifying the drivers of long-term population change is a key goal of ecological studies. It is complicated by extrinsic and intrinsic factors that may covary with time and/or operate on a time lag. For migratory shorebirds that breed on the barrier islands of eastern North America, populations may be limited by the anthropogenic, climatic, biological environments they encounter throughout the annual cycle. Using three-decades (1989–2017) of breeding monitoring data collected by the National Park Service at two national seashores in North Carolina (Hatteras and Lookout), we examined the potential drivers of nesting piping plover (Charadrius melodus) and American oystercatcher (Haematopus palliates) populations. Hatteras had five times more annual visitors than Lookout, and our modelling revealed a strong negative relationship between the population size of breeding plovers and human activity and a positive relationship with protection efforts aimed at reducing disturbance. Breeding and wintering climatic conditions, population productivity, and nesting habitat availability showed only weak effects. Thus, a decade-long decline in plover numbers at both seashores starting in the mid-90s reversed as the parks' visitor counts decreased and stricter protections from potential disturbance were implemented. However, the two sympatric populations of oystercatchers showed the opposite population trends from each other at the neighboring seashores, increasing only on Lookout after a hurricane improved habitat and subsequently the reproductive output. Our study suggests a strong relationship between the anthropogenic environment and the population trend of a threatened species and, simultaneously, the important role of stochastic events in shaping populations of long-lived shorebird species.

American Oystercatcher benefits from a heterogeneous landscape to breed in an urbanized area in southern Brazil

American Oystercatcher benefits from a heterogeneous landscape to breed in an urbanized area in southern Brazil

Breeding biology of the American Oystercatcher Haematopus palliatus on a key site for conservation in southern Brazil

Breeding biology of the American Oystercatcher Haematopus palliatus on a key site for conservation in southern Brazil

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

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

Organochlorine Pesticides and Polychlorinated Biphenyls in American Oystercatchers Nesting along the Texas Gulf Coast

The American Oystercatcher (Haematopus palliatus palliatus) is an important breeding species along the Texas Gulf Coast, particularly between Galveston Bay and Corpus Christi, Texas, USA. American Oystercatchers are considered a species of greatest conservation need and are on the priority list for conservation by the National Fish and Wildlife Foundation. American Oystercatchers feed mainly on oysters (Ostreidae) and other bivalves, which are known to accumulate significant amounts of pollutants. We determined accumulation and potential effects of environmental contaminants, particularly organochlorine (OC) pesticides and polychlorinated biphenyls (PCBs) in blood of American Oystercatchers nesting along the Texas Gulf Coast, USA during 2012 and 2013. Plasma concentrations of OCs and PCBs were low. The most commonly detected OC pesticides were HCB, HCH, α chlordane, endosulfan, methoxychlor, p,p'-DDD, and p,p'-DDE. Total p,p'-DDE concentrations ranged from 2-10 ng/mL ww and total PCB concentrations ranged from 2-54 ng/mL ww. Mean p,p'-DDE concentrations were similar among regions; however, total PCBs were significantly greater (P = 0.0056) in blood from adult birds from West Galveston Bay, Texas, USA in 2013 than in blood from young collected in 2012, mostly also from West Galveston Bay. Overall, concentrations of OC pesticides in plasma were low; however, some PCB concentrations were above the NOAEC levels that have been associated with normal reproduction in other bird species.

Loss of Coastal Islands Along Florida’s Big Bend Region: Implications for Breeding American Oystercatchers

Many coastal-dependent species have undergone large-scale population declines due to impacts from habitat loss, including American oystercatchers (Haematopus palliatus). Islands along the Big Bend region of Florida’s Gulf Coast provide important nesting habitat for oystercatchers, but reproductive success here is low and habitat degradation and loss are a major concern. To determine rates and characteristics of habitat loss, we quantified changes in island sizes within two major breeding areas of the Big Bend: the Barge Canal spoil islands and natural islands at Cedar Key. We digitized aerial photographs from the past ~ 40 years, measured area and shoreline retreat of nesting islands, and identified trends over time by fitting linear mixed effects models. The total area of the ten Barge Canal spoil islands decreased by 55% between 1979 and 2016. At Cedar Key, the total area of the six islands measured decreased by 39% between 1974 and 2016, 85% of which occurred after 1995, indicating an increase in erosion rates correlated with oyster reef declines. Changes in available nesting habitat varied between the Barge Canal and Cedar Key islands due to differences in physical attributes; however, all islands significantly decreased in size over time. Given the long life and high site fidelity of American oystercatchers, these islands may currently be acting as an ecological trap for this species. Climate change, sea-level rise, and loss of oyster reefs are likely to continue to drive oystercatcher habitat loss throughout their range; thus, creation and restoration of oyster reefs and nesting islands will become increasingly important.

Poblaciones reproductivas de aves playeras en humedales del noroeste mexicano

Una época crítica para los organismos es la reproductiva, pues de ella dependen, en parte, la salud y el tamaño de las poblaciones. Generar información sobre este aspecto permite tomar adecuadas decisiones de manejo o conservación. Para evaluar la importancia del noroeste de México en la reproducción de nueve especies de aves playeras, estudiamos, en mayo de 2017, a sus poblaciones en 12 sitios, localizados en Baja California Sur (3), Sonora (3), Sinaloa (4), límites entre Baja California y Sonora (1) y Sinaloa y Nayarit (1). Realizamos conteos y búsqueda de evidencia reproductiva, en la costa. Registramos nueve especies hipotéticamente reproductivas y un híbrido (Haematopus palliatus x H. bachmani). Obtuvimos 6,960 registros de aves playeras, donde sobresalieron Himantopus mexicanus (42%), Recurvirostra americana (32%) y H. palliatus (18.4%). Los sitios con mayores abundancias fueron Marismas Nacionales (35%), Huizache-Caimanero (13%), Yavaros-Moroncárit (12.5%) y Bahía de Tóbari (12%), todos ubicados en el continente. Para tres especies (H. palliatus, Charadrius nivosus y Ch. wilsonia) los individuos reproductores representaron un porcentaje importante de su total poblacional. Esta investigación reafirma la importancia del noroeste de México para la reproducción de aves playeras residentes, algunas protegidas por el gobierno mexicano.

Reproduction of the American Oystercatcher (“piru-piru”), Haematopus palliatus Temminck 1820 (Aves: Haematopodidae), in northeastern Brazil

ABSTRACT Haematopus palliatus (American Oystercatcher, locally called ‘piru-piru’) is strictly a coastal bird, which occurs from Canada to the southern end of South America. The species is distributed along the entire Brazilian coast, however, approximately 50% of the population is estimated to be concentrated in the Rio Grande do Sul State, where it reproduces during the austral spring and summer. This study presents the first documented reproduction records of H. palliatus from 2004 to 2019 in northeastern Brazil in: Piauí State, Maramar Beach (02°54’S, 41°28ʹW); Ceará State, Banco dos Cajuais Beach (04°41’S, 37°21ʹW); Rio Grande do Norte State, west of the Amaro (05°05’S, 36°25ʹW) and Salina Soledade (05°06’S, 36°32ʹW) beaches; and Bahia State, Mangue Seco Beach (11°27’S, 37°21ʹW). The reproductive period of these birds initiated at the end of May and extended through mid-October. Their nests are simple and bare, consisting of a shallow cavity in the sand on open areas with or without low vegetation. The inspected nests had from one to three eggs, whose colours and shapes were similar to those observed in other regions. Most eggs were lost, apparently due to predation. Various anthropic threats were observed in the four study areas, especially the circulation of motorised vehicles and the presence of domestic dogs and cattle. Loss of habitat quality and real estate speculation, however, are among the main threats to the future of the species in northeastern Brazil, indicating the importance of proactive measures for the conservation of H. palliatus.

Reproductive success of Haematopus palliatus, the Common oystercatcher, and anthropic activities in the Marvilla Circuit, Pantanos de Villa, Lima- Peru

Reproductive success of Haematopus palliatus, the Common oystercatcher, and anthropic activities in the Marvilla Circuit, Pantanos de Villa, Lima- Peru

Breeding population size and trends of American Oystercatchers on small islands of Bahía Santa María‐La Reforma, Sinaloa, Mexico

Breeding population size and trends of American Oystercatchers on small islands of Bahía Santa María‐La Reforma, Sinaloa, Mexico

Substrate-Level Nest Site Selection of Sympatric Piping Plovers (Charadrius melodus) and American Oystercatchers (Haematopus palliatus) in New Jersey, USA

Piping Plovers (Charadrius melodus) and American Oystercatchers (Haematopus palliatus) are shorebird species of conservation concern that breed sympatrically along the U.S. Atlantic coast, facing substantial anthropogenic habitat loss and disturbance. Interspecific aggression has been increasingly observed in overlapping habitat, potentially resulting in diverting time and energy that would be available for breeding activities. Because nests are camouflaged against the substrate, nest site habitat is important to fitness. Understanding habitat selection disparities could inform management of both species while ameliorating agonistic interactions. Nest sites in New Jersey were compared with paired random sites based on median proportions of substrate covered by rock, shell, wrack, plant, and other items (including peat and plastic litter). Both American Oystercatchers (n = 37 nests) and Piping Plovers (n = 42 nests) selected certain substrate features in amounts disproportionate to their availability, and interspecific differences were present. For American Oystercatchers, wrack constituted 17.7% of the substrate at nest sites versus 2.0% at paired sites. Piping Plover nest sites had greater proportions of shells, and medium fragments (2-64 mm) alone represented 18.9% of nest substrate versus 6.3% at paired sites. Results indicate that substrate management may be effective in creating ecological separation between these species.

Asymmetric Antagonism between Piping Plovers (Charadrius melodus) and American Oystercatchers (Haematopus palliatus), New York, USA

Anecdotal observations of American Oystercatchers (Haematopus palliatus) destroying Piping Plover (Charadrius melodus) eggs and killing Piping Plover chicks may be limiting Piping Plover productivity. Therefore, 212 focal observations of Piping Plovers and American Oystercatchers were recorded during the 2011 and 2012 breeding seasons at Breezy Point, New York, USA. Thirty agonistic interspecific interactions were observed, almost half (n = 13) of which occurred between Piping Plovers and American Oystercatchers. Piping Plovers initiated significantly more agonistic interactions (76%, n = 13) toward American Oystercatchers than those initiated by American Oystercatchers (8%, n = 13) toward Piping Plovers. All agonistic interactions between Piping Plovers and American Oystercatchers began after one of the species entered the territory of the other. These interactions appear to have a higher potential for fitness reduction in Piping Plovers than American Oystercatchers, and occurred approximately once every 12 hr of observation. Due to the similarity between nesting habitats of Piping Plovers and American Oystercatchers, a plan that focuses on habitat enhancement for beach-nesting birds rather than individual species is recommended.