Historic Biogeography of Polynesian Birds: Effects of Physical Characters of Islands on Faunal Attributes

9714819对南太平洋岛屿现代陆鸟群落的斯蒂德曼分析为生物地理学理论做出了重要贡献。然而，在东波利尼西亚群岛(马尔科萨斯群岛、社会群岛、图阿莫图群岛、皮特凯恩群岛和库克群岛)，地鸟多样性和地方性的自然格局被人为灭绝所掩盖。史前东波利尼西亚鸟类区系在物种丰富度(无论是在岛群之间和岛群内)上比来自相同岛屿的现代鸟类区系要同质得多，无论岛屿面积、海拔或与世隔绝。大多数特有物种仅限于不会飞的物种。东波利尼西亚鸟类的数据并不早于公元前2000年人类的到来。这项新的研究将通过收集和分析汤加、萨摩亚和斐济等不太偏远的西波利尼西亚岛群中准确年代的史前遗址的骨骼组合，来研究南太平洋鸟类群落在更长的时间尺度(长达10万年前)的组成和稳定性。更古老的动物群记录可以在西波利尼西亚建立，因为在人类之前的时代，当地的捕食性鸟类在洞穴中集中了骨骼。新的数据将提供一个机会，以估计物种丰富度，分类多样性，和周转(灭绝/殖民)率在西波利尼西亚地鸟在人类存在之前和之后。据预测，与经典的生物地理学理论相反，在前人类时代，岛屿面积(10 km2-104 km2)、海拔(101-103m)和隔离(0-800 km)的变化对西波利尼西亚鸟类区系的物种丰富度或分类多样性影响很小，周转率很低。换句话说，这些鸟类群落丰富，但在自然条件下稳定，殖民率和灭绝率极低。从古生物学的角度来看，真正的海洋岛屿上物种的存在可能并不像研究现代鸟类的人通常认为的那样短暂。

9714819 Steadman Analyses of modern landbird communities on South Pacific islands have made important contributions to biogeographic theory. In East Polynesia (Marquesas, Society, Tuamotu, Pitcairn, and Cook island groups), however, natural patterns of diversity and endemism among landbirds have been obscured by human-caused extinction's. Prehistoric East Polynesian avifaunas were much more homogeneous than modern avifaunas from the same islands in species richness (both between and within island groups), regardless of island area, elevation, or isolation. Most endemism was restricted to flightless species. Data on East Polynesian birds do not precede the arrival of humans at 2000 yr BP. The new research will examine the composition and stability of South Pacific bird communities over much longer time scales (up to 100,000 yr BP) by collecting and analyzing bone assemblages from precisely dated prehistoric sites in the less remote West Polynesian island groups of Tonga, Samoa, and Fiji. Older faunal records can be developed in West Polynesia because indigenous predatory birds have concentrated bones in caves there during pre-human times. The new data will provide an opportunity to estimate species richness, taxonomic diversity, and turnover (extinction/colonization) rates in West Polynesian landbirds both before and after human presence. It is predicted that, counter to classic biogeographic theory, variation in island area (10( - 104 km2), elevation (101-103 m), and isolation (0-800 km) had little influence on species richness or taxonomic diversity in West Polynesian avifaunas in pre-human times, and that turnover rates were very low. In other words, these bird communities were rich but stable under natural conditions, with extremely low rates of colonization and extinction. From a paleontological perspective, the existence of species on true oceanic islands may not be as ephemeral as is generally believed by those who study modern birds.