Final report to the Gulf Coast Joint Venture: Black Skimmer and Gull-billed Tern

Abstract

Many bird species are of conservation concern across the Northern Gulf of Mexico from stressors such as human disturbance, predation, and habitat loss due to directional environmental change (e.g., increased sea-level rise and storm frequency and intensity, human infrastructure, changes in land use). Consequently, managers need decision-support tools that can help to answer important conservation questions for different species (e.g., which areas and how much area should be targeted by management actions to meet a particular species’ needs). The Black Skimmer ( Rynchops niger ; hereafter Skimmer) and Gull-billed Tern ( Gelochelidon nilotica ; hereafter Tern) are designated as U.S. Fish and Wildlife Service (USFWS) Species of Conservation Concern and Gulf Coast Joint Venture (GCJV) Priority Species with nesting habitats in the USFWS Gulf Coast Biological Planning Units (BPU; Tirpak et al. 2017). They are also representative of a variety of other beach and barrier-island nesting birds whose Gulf Coast nesting habitats are threatened by directional environmental change. The Skimmer has breeding pair targets in six GCJV Initiative Areas (IA), and the Tern has breeding pair targets in five GCJV IAs. Our goal was to inform GCJV management scenarios that efficiently and simultaneously achieve both species’ targets by prioritizing sites where management actions (e.g., maintain existing habitat or change habitat, geomorphology [landmass area, landmass elevation], predator management, human and dog restrictions) could be implemented.