An island of wildlife in a human-dominated landscape: The last fragment of primary forest on the Osa Peninsula’s Golfo Dulce coastline, Costa Rica

Habitat loss and fragmentation, together with related edge effects, are the primary cause of global biodiversity decline. Despite a large amount of research quantifying and demonstrating the degree of these effects, particularly in top predators and their prey, most fragmented patches are lost before their conservation value is recognized. This study evaluates terrestrial vertebrates in Playa Sandalo, in the Osa Peninsula of Costa Rica, which represents the last patch of “primary” forest in the most developed part of this region. Our study indicates that the diversity of ground species detected within Playa Sandalo rival other areas under active conservation like Lapa Rios Ecolodge. Historical fragmentation, together with the maintenance of forest cover in isolated conditions, are potentially responsible for the species composition observed within Playa Sandalo; facilitating the development of a prey-predator system including ocelots, medium-size mammals, and birds at the top of the trophic chain. The high diversity of both habitat and vertebrates, its prime location and cultural value, as well as its unique marine importance represent the ideal conditions for conservation. Conservation of Playa Sandalo, and other small tropical forest remnants, might represent the only management option for wildlife conservation within ever growing human-dominated landscapes.

生境丧失与片段化及其伴生的边缘效应，是全球生物多样性下降的首要诱因。尽管已有大量研究量化并阐明了此类效应的程度，尤其是针对顶级捕食者及其猎物类群，但绝大多数片段化生境斑块在其保护价值得到确认前便已消失殆尽。本研究对哥斯达黎加奥萨半岛普拉亚桑达洛（Playa Sandalo）的陆生脊椎动物展开评估，该区域乃是该半岛开发程度最高区域内仅存的“原生”林斑块。本研究显示，普拉亚桑达洛内监测到的地面物种多样性，可与拉帕里奥斯生态旅馆（Lapa Rios Ecolodge）等正开展积极保护工作的区域相媲美。历史片段化作用，加之孤立状态下森林覆盖的维持，或是普拉亚桑达洛内观测到的物种组成的潜在成因；这一过程助力形成了包含虎猫、中型哺乳动物以及食物链顶端鸟类在内的捕食-猎物种群系统。该区域兼具极高的生境与脊椎动物多样性，加之优越的地理位置、文化价值，以及独特的海洋重要性，共同构成了理想的保护条件。对普拉亚桑达洛及其他小型热带森林残余斑块实施保护，或许是在不断扩张的人类主导景观中开展野生动物保护的唯一可行管理方案。