Evaluating a focal-species approach for tidal marsh bird conservation in the northeastern United States | Évaluation de l'approche par espèce focale pour la conservation des oiseaux de marais côtiers dans le nord-est des États-Unis

Insufficient time and funding remain obstacles to collecting data across broad spatial scales on the fine-scale distribution of multiple species, their life histories, and interactions with other species and the environment. This often necessitates the use of focal species to inform conservation and management decisions. We used the systematic conservation-planning software Marxan to assess quantitatively whether a focal species can aid in conservation and management of tidal marsh birds. Using a metric of relative cost in the region and current protected areas, we identified priority areas for conservation of 5 specialist taxa—Clapper Rail (Rallus crepitans), Eastern Willet (Tringa semipalmata semipalmata), Acadian Nelson's Sparrow (Ammospiza nelsoni subvirgatus), Saltmarsh Sparrow (A. caudacuta), and Seaside Sparrow (A. maritima)—that nest primarily in tidal marshes in the northeastern United States. We compared the spatial prioritization of sites and cost-effectiveness of alternative protection scenarios that considered individual species, groups of species, and all species simultaneously to evaluate the appropriateness of a focal-species approach. Scenarios that prioritized areas for conservation based on single-species targets were poorly correlated across species. Scenarios based on Saltmarsh Sparrow conservation were most strongly related (rₛ = 0.759) to site prioritizations that considered all 5 tidal marsh specialists simultaneously. When comparing multispecies combinations to prioritizations based on the Saltmarsh Sparrow alone, the estimated costs, area of land protection, and number of individuals of each species protected were similar. These results suggest that no species is a good surrogate for another but that the Saltmarsh Sparrow may be a viable focal species for conservation planning to protect tidal marsh birds as a group. By evaluating protection scenarios for all species, we were able to identify areas where conservation is likely to have little or no effect, which could be as important for decision making as identifying the best sites.