Search for: All records

Atlantic ghost crabs (Ocypode quadrata) are predators of beach-nesting shorebird nests and chicks on the United States’ Atlantic and Gulf coasts. Ghost crabs may also disturb birds, altering foraging, habitat use, or nest and brood attendance patterns. Shorebird conservation strategies often involve predator and disturbance management to improve reproductive success, but efforts rarely target ghost crabs. Despite the threat to shorebird reproductive success, ghost crabs are a poorly understood part of the beach ecosystem and additional knowledge about ghost crab habitat selection is needed to inform shorebird conservation. We monitored ghost crab activity, defined as burrow abundance, throughout the shorebird breeding season on Metompkin Island, Virginia, an important breeding site for piping plovers (Charadrius melodus) and American oystercatchers (Haematopus palliatus). We counted burrows at shorebird nests and random locations throughout the breeding season and investigated whether ghost crab activity was greater at nest sites relative to random locations without shorebird nests. While we observed burrows at all nest sites (n= 63 nests), we found that burrow counts were lower at piping plover nests with shell cover, relative to random locations with no shell cover. Ghost crabs may avoid piping plover nest sites due to anti-predator behaviors from incubating adults or differences in microhabitat characteristics selected by piping plovers. We also investigated the effects of habitat type, date, and air temperature on the abundance of ghost crab burrows. We found that while crab burrows were present across the barrier island landscape, there were more burrows in sandy, undisturbed habitats behind the dunes, relative to wave-disturbed beach. Additionally, ghost crab activity increased later in the shorebird breeding season. Understanding when and where ghost crabs are most likely to be active in the landscape can aid decision-making to benefit imperiled shorebird populations. 

Shorebird reproductive success monitoring often relies on surveys of nest and brood survival. However, conclusions may be inaccurate due to the challenges of gathering and interpreting evidence of nest and brood fate. We tested the efficacy of in-person versus camera- based monitoring to quantify productivity and evaluate threats to reproductive success of American Oystercatchers (Haematopus palliatus) and Piping Plovers (Charadrius melodus) at Metompkin Island, Virginia. We deployed 73 cameras using three set-ups: at nests, at brood sites, and along a transect. The same areas were also surveyed in-person approximately once per week. Camera monitoring confirmed nest fate where in-person monitors could not determine fate from field evidence and provided insight to the effectiveness of mammalian predator removal. However, cameras failed to capture causes of mortality for mobile chicks and did not consistently document chicks where in-person monitoring confirmed successful broods. Cameras produced large quantities of data requiring 63.5–315 hours to review, depending on camera set- up. We found cameras were useful for validating conclusions from in-person monitoring, highlighting threats that surveys missed, and characterizing the predator community. Managers should consider the tradeoff between potential benefits and required effort of camera monitoring when deciding which method would be effective for meeting management goals. 

Abstract Tidal marshes store large amounts of organic carbon in their soils. Field data quantifying soil organic carbon (SOC) stocks provide an important resource for researchers, natural resource managers, and policy-makers working towards the protection, restoration, and valuation of these ecosystems. We collated a global dataset of tidal marsh soil organic carbon (MarSOC) from 99 studies that includes location, soil depth, site name, dry bulk density, SOC, and/or soil organic matter (SOM). The MarSOC dataset includes 17,454 data points from 2,329 unique locations, and 29 countries. We generated a general transfer function for the conversion of SOM to SOC. Using this data we estimated a median (± median absolute deviation) value of 79.2 ± 38.1 Mg SOC ha⁻¹in the top 30 cm and 231 ± 134 Mg SOC ha⁻¹in the top 1 m of tidal marsh soils globally. This data can serve as a basis for future work, and may contribute to incorporation of tidal marsh ecosystems into climate change mitigation and adaptation strategies and policies.