Data from: Crossing the (Wallace) line: local abundance and distribution of mammals across biogeographic barriers

Past and ongoing vertebrate introductions threaten to rearrange ecological communities in the Indo-Malay Archipelago, one of Earth’s most biodiverse regions. But the consequences of these translocations are difficult to predict. We compared local abundance and distributions in four tropical mammal lineages that have crossed from Asia to Wallacea or New Guinea. The local abundance of macaques (Macaca spp.), which naturally crossed Wallace’s Line, was higher in Sulawesi (east of the line; mean = 3.7 individuals per camera station, 95% CI = 2.2 : 5.1) than in Borneo (west of the line; mean = 1.1, CI = 0.8 : 1.4), but the local abundance of Malay civets (Viverra tangalunga), Rusa deer, and Sus pigs was similar in their native ranges and where they had been introduced by humans east of Wallace’s Line. Proximity to rivers increased Malay Civet local abundance and decreased the local abundance of pigs in parts of their introduced ranges (Maluku and New Guinea, respectively), while having no effect on local abundance in their native ranges (Borneo) or other areas where they have been introduced (Sulawesi). That local abundance was higher east of Wallace’s Line in just one out of four mammal lineages is consistent with findings from plant invasions, where most species have similar abundance in their native and introduced ranges. However, species’ ecology may change as they enter new communities, for example their patterns of abundance at local scales. This could make it difficult to predict community structure in the face of ongoing species introductions.过去与当前持续进行的脊椎动物引入（vertebrate introductions）活动，正威胁重塑地球生物多样性最丰富的区域之一——印度-马来群岛（Indo-Malay Archipelago）的生态群落。但此类物种移殖所带来的生态后果却难以预测。本研究针对四个已从亚洲扩散至华莱士区（Wallacea）或新几内亚的热带哺乳类类群，对比了其局域种群多度与分布格局。自然跨越华莱士线（Wallace’s Line）的猕猴属（Macaca spp.）类群，其在苏拉威西岛（Sulawesi，华莱士线以东；均值=每相机诱捕位点（camera station）3.7只个体，95%置信区间（CI）：2.2~5.1）的局域种群多度，显著高于婆罗洲（Borneo，华莱士线以西；均值=1.1，CI：0.8~1.4）；但马来灵猫（Viverra tangalunga）、水鹿及猪属（Sus）野猪的局域种群多度，在其自然分布区与被人类引入至华莱士线以东的区域中无显著差异。在马来灵猫与野猪的部分引入分布区（分别为马鲁古群岛（Maluku）与新几内亚）中，临河距离越近，马来灵猫的局域种群多度越高，而野猪的局域种群多度则越低；但在其自然分布区婆罗洲，或是其他引入区域苏拉威西岛中，临河距离并未对其局域种群多度产生显著影响。四类哺乳类类群中仅有一种在华莱士线以东的局域种群多度更高，这一结果与植物入侵领域的研究发现相符——多数入侵植物在其自然分布区与引入分布区的种群多度并无显著差异。然而，物种进入全新群落后，其生态特征可能发生改变，例如局域尺度下的种群多度格局。这意味着在当前持续不断的物种引入事件中，我们难以准确预测生态群落的结构变化。