Managing birds of conservation concern on sandy shores: How much room for future conservation actions is there?

Abstract

Resource limitations often prevent the active management required to maintain habitat quality in protected areas. Because restrictions in access or allowable public activities are the sole conservation measure in these locations, an important question to consider is whether species of conservation concern truly benefit from parcels that are shielded from human disturbance. Here, we assess the conservation benefit of protecting birds from human recreation on over 204 km of sandy beaches by (a) estimating the total area of beach‐nesting bird habitat that has been created by conservation protections; (b) quantifying the change in nesting habitat extent should further conservation protections be implemented; and (c) providing data to inform future protected area expansion. We use a maximum entropy species distribution modeling approach to estimate the extent and quality of suitable habitat for four beach‐nesting bird species of conservation concern under the existing management regime and compare it to scenarios in which the entire study area is either unprotected of fully protected from human disturbance. Managing humans has dramatic conservation returns for least terns and piping plovers, creating extensive nesting habitat that otherwise would not exist. There is considerable scope for conservation gains, potentially tripling the extent of nesting areas. Expanding conservation footprints for American oystercatchers and black skimmers is predicted to enhance the quality of existing nesting areas. The work demonstrates the utility of modeling changes in habitat suitability to inform protected area expansion on ocean beaches and coastal dunes.

Hurricane Sandy and engineered response created habitat for a threatened shorebird

“…Many unprotected areas had frequent ORV traffic, boaters landing on the shore, and pedestrian use. Maslo et al (2018) simulated a scenario where piping plover habitat along the New Jersey coast was entirely protected from recreational use and predicted a 2.6-fold increase in suitable habitat. 7).…”

“…Pedestrian and ORV use can alter invertebrate communities and disturb nesting and foraging birds directly (e.g., moving vehicles, pedestrians) and indirectly (tire ruts; Schlacher and Thompson 2008; Fig. Conversely, under an unprotected scenario (where no human disturbance protections existed), only a fraction of suitable habitat remained (Maslo et al 2018). In our study area, tire ruts predate piping plovers' arrival on the islands, and beaches are driven on daily during March-May when birds are establishing territories.…”

“…Fish and Wildlife Service [USFWS] 1985). Suitable piping plover nesting habitat is unlikely to be used in some areas without active management to prevent recreational beach use (Maslo et al 2018), which may directly or indirectly affect beachnesting birds Thompson 2008, Defeo et al 2009). Atlantic coast piping plovers nest in small depressions on sparsely vegetated dry sand on barrier islands (Wilcox 1959, Cairns 1982, Cohen et al 2008, and they reach their highest densities (pairs/hectare) where sand spans the distance from the ocean to the bay shoreline (Cohen et al 2009).…”

A pragmatic approach for comparing species distribution models to increasing confidence in managing piping plover habitat

“…Previous comparisons between these scenarios (Maslo et al, 2018) show that human disturbance significantly reduces the quality of otherwise geomorphically suitable nesting habitat, rendering it unsuitable for breeding. In each case, we modified the human disturbance predictor variable in Maxent to account for the amount of land within the study area protected for conservation purposes.…”

“…Particularly in the New York-New Jersey region, where this research was focused, piping plover population growth is inhibited by a lack of suitable habitat resulting from dense coastal development, significant human disturbance, pressure from non-native and human-adapted predators, and the consequences of habitat-insensitive beach stabilization practices (e.g., Greene, 2002;Maslo et al, 2018;Maslo & Lockwood, 2009;Robinson et al, 2019). Typically, habitat protections are not instituted in new areas unless a federally or state-listed species is observed there.…”