Abstract

Disturbance from human activity can cause reduced productivity of coastal birds that nest on sandy beaches. A common method to protect coastal birds from human disturbance is the use of signs and fencing to close off a section of beach used for breeding. This management action requires public compliance and might require enforcement, such as in the use of volunteer stewards stationed at protected colonies that provide education and enforcement. I assessed the effectiveness of active stewardship as a conservation measure to protect nesting Least Terns (Sternula antillarum) in coastal Mississippi by determining if colony-level productivity (fledglings produced per nest) was correlated with stewardship effort (hours that stewards protected each colony), the rate of disturbance from human and natural sources, and additional factors. Observers surveyed 24 Least Tern colonies in Harrison County, Mississippi, twice weekly during the 2017–2019 breeding seasons to record the number of nests present, the fate of marked nests, predator tracks within the colony, and the number of fledglings produced per colony. Concurrently, during their work shifts, stewards recorded all sources and durations of disturbance events that caused the terns to flush or respond with defense. Least Tern daily nest survival increased with colony size and stewardship effort, and was lower during intervals that included weekends and evidence of owl presence. Total productivity was negatively associated with avian predator disturbance rate and the total time adults spent flushed, but was not associated with stewardship effort. The results of this study demonstrate that active stewardship can have a positive effect on Least Tern productivity by increasing nest success, whereas current stewardship practices were not sufficient to increase chick survival, even in a system with a paucity of ground predators.

中文翻译：

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密西西比州沿海地区管理对最小燕鸥繁殖成功影响的混合证据

摘要

来自人类活动的干扰会导致在沙滩上筑巢的沿海鸟类生产力下降。保护沿海鸟类免受人类干扰的一种常用方法是使用标志和围栏来封闭用于繁殖的海滩区域。这种管理行动需要公众遵守，并可能需要执行，例如，使用设在受保护的殖民地的志愿服务员来提供教育和执行。我评估了主动管理作为一种保护措施，以保护嵌套的最小燕鸥（Sternula antillarum）的有效性。），方法是确定密西西比州沿海地区的菌落水平生产力（每个巢中产生的雏鸟）是否与管理工作量（管家保护每个菌落的小时数），人为和自然资源的干扰率以及其他因素相关。观察员在2017-2019繁殖季节每周两次对密西西比州哈里森县的24个最小燕鸥殖民地进行调查，以记录现存的鸟巢数量，标记巢的命运，殖民地内的捕食者踪迹以及每个殖民地产生的雏鸟数量。同时，管家在轮班期间记录了导致燕鸥潮红或做出防御反应的骚扰事件的所有来源和持续时间。燕鸥的日常巢生存率随着群体规模和管理工作的增加而增加，并且在包括周末和猫头鹰在场的证据的时间间隔内较低。总生产力与鸟类捕食者干扰率和成年人花时间总时间呈负相关，但与管理工作无关。这项研究的结果表明，积极的管理可以通过增加筑巢的成功率来对最小燕鸥的生产力产生积极的影响，而即使在缺乏地面掠食性动物的系统中，目前的管理方法也不足以增加雏鸡的存活率。