Effects of stewardship on protected area effectiveness for coastal birds

Evaluation of protected area effectiveness is critical for conservation of biodiversity. Protected areas that prioritize biodiversity conservation are, optimally, located and managed in ways that support relatively large and stable or increasing wildlife populations. Yet evaluating conservation efficacy remains a challenging endeavor. Here, we utilize an extensive community science dataset, eBird, to evaluate the efficacy of protected areas for birds across the Gulf of Mexico and Atlantic coasts of the United States (US). We model trends (2007 - 2018) for 12 vulnerable waterbirds that use coastal areas during breeding or wintering. We compare two types of protected areas - sites where conservation organizations implemented active stewardship and/or management to reduce human disturbance (hereafter 'stewardship sites'); and local, state, federal, and private protected areas managed to maintain natural landcover (hereafter 'protected areas') - as well as unprotected areas. We evaluated differences in trends between stewardship, protected, and unprotected areas across the Gulf and Atlantic coasts as a whole. Similar to a presence/background analysis, stewardship was known to occur at stewardship sites, but unknown at protected and unprotected areas. Four of 12 target species - Black Skimmer (Rhynchops niger), Brown Pelican (Pelecanus occidentalis), Least Tern (Sternula antillarum), and Piping Plover (Charadrius melodus) - had more positive trends (2 - 34x greater) at stewardship sites than protected areas. Furthermore, five target species showed more positive trends at sites with stewardship programs relative to unprotected sites during at least one season, while seven species showed more positive trends at protected than unprotected areas. Notably, no species had more negative trends at stewardship sites than unprotected areas, while two species had more negative trends at protected than unprotected areas. Anthropogenic disturbance is a serious threat to coastal birds, and our findings demonstrate that stewardship to reduce its negative impacts helps ensure conservation of vulnerable waterbirds. Article Impact Statement: Stewardship programs that reduce human disturbance increase protected area effectiveness for vulnerable coastal waterbirds. This article is protected by copyright. All rights reserved.