Smartphone-Based Distributed Data Collection Enables Rapid Assessment of Shorebird Habitat Suitability (Extract)

Introduction

The coastal zone is a highly dynamic environment that changes in response to a variety of short-and long-term processes, such as storms, natural vegetation succession, anthropogenic modifications, climate change, and sea-level rise. However, the range of physical and biological responses of beach environments to climate change and sea level rise is poorly understood at the temporal and spatial scales required for decision making[1]. Similarly, the cumulative impacts of physical and biological change on the quantity and quality of coastal habitats are not well understood, which poses a challenge for natural resource management[2].

Observations of species, their local context, and population dynamics are necessary to understand and predict changes in habitat availability and utilization[3]. Many shorebird species, including the piping plover (Charadrius melodus), utilize habitats found on coastal beaches. The piping plover was listed as threatened along the U.S. Atlantic coast in 1986[4]; recent estimates place the population at fewer than 2000 pairs[5]. As a federally listed species, the conservation and recovery of this species is administered under provisions of the Endangered Species Act of 1973 and includes both population-and habitat-level management recommendations. Because of the dynamic nature of piping plover habitat, the efficacy of future conservation resource allocation and management can be improved by understanding which actions are most likely to increase the persistence and resilience of sensitive coastal habitats. Thus, ongoing species recovery efforts can benefit from information about the future distribution and attributes of plover breeding habitat, particularly under potential threats like sea-level rise and coastal engineering.

Atlantic coast piping plover nest sites are typically found on low-lying beach and dune systems (Fig 1; [6, 7]). These birds and their habitats respond rapidly to coastal processes like sediment overwash, inlet formation, and island migration[8]that are sensitive to climate-related changes in storminess and the rate of sea-level rise. The piping plover may also serve as a surrogate species for other beach-nesting shorebirds (e.g., American oystercatcher, Haematopus palliates; least tern, Sternula antillarum; black skimmer, Rynchops niger) as well as several federally listed birds (e.g., rufa red knot, Calidris canutus rufa), plants (e.g., seabeach amaranth, Amaranthus pumilus), and insects (e.g., northeastern beach tiger beetle, Cicindela dorsalis dorsalis). Therefore, the ability to predict piping plover habitat availability in the face of climate change can have broad applicability to a variety of coastal species.

As part of the species' recovery plan[9], piping plovers are observed by a large number of trained monitors throughout their geographic distribution[10]. Monitors represent federal and state agencies, nongovernmental organizations, and land-owning trusts and possess varying levels of expertise in environmental assessment and use of specialized equipment (e.g., global navigation satellite system receiver, GNSS).

Acquiring data needed to quantify and understand piping plover biogeomorphic preferences for nesting habitat required a tool designed to handle diverse users and challenging conditions. Data needed to be standardized and collected synoptically in a harsh environment that includes bright sun, windblown sand, and salt spray. Such data collection often requires multiple prohibitively expensive devices. Thus, a satisfactory solution for data collection along ~1500 km of coastline required a low-cost but adequate device with multiple sensors that could operate in a demanding environment. In addition, an analysis method was necessary that could accommodate a dataset with varying levels of accuracy and subjective observations of habitat characteristics.

Here we describe the development, initial field deployment, and subsequent modification of a smartphone application called iPlover that supports investigations of the effects of coastal change on piping plover habitat availability and utilization. This work is one component of a larger research and management program that seeks to understand and sustain ecological value, ecosystem services, and habitat suitability of beaches in the face of storm impacts, climate change, and sea-level rise.