Macroecological database of mammalian body mass

The purpose of this data set was to compile body mass information for all mammals on Earth so that we could investigate the patterns of body mass seen across geographic and taxonomic space and evolutionary time. We were interested in the heritability of body size across taxonomic groups (How conserved is body mass within a genus, family, and order?), in the overall pattern of body mass across continents (Do the moments and other descriptive statistics remain the same across geographic space?), and over evolutionary time (How quickly did body mass patterns iterate on the patterns seen today? Were the Pleistocene extinctions size specific on each continent, and did these events coincide with the arrival of man?). These data are also part of a larger project that seeks to integrate body mass patterns across very diverse taxa (NCEAS Working Group on Body size in ecology and paleoecology: linking pattern and process across space, time and taxonomic scales). We began with the updated version of Wilson and Reeder's (1993) taxonomic list of all known Recent mammals of the world (N = 4629 species) to which we added status, distribution, and body mass estimates compiled from the primary and secondary literature. Whenever possible, we used an average of male and female body mass, which was in turn averaged over multiple localities to arrive at our species body mass values. The sources are line referenced in the main data set, with the actual references appearing in a table within the metadata. Mammals have individual records for each continent they occur on. Please note that our data set is more than an amalgamation of smaller compilations. Although we relied heavily a data set for Chiroptera by K. E. Jones (N = 905), the CRC handbook of Mammalian Body Mass (N = 688), and a data set compiled for South America by P. Marquet (N = 505), these total less than half the records in the current database. The remainder are derived from more than 150 other sources (see reference table). Furthermore, we include a comprehensive late Pleistocene species assemblage for Africa, North and South America, and Australia (an additional 230 species). "Late Pleistocene" is defined as approximately 11 ka for Africa, North and South America, and as 50 ka for Australia, because these times predate anthropogenic impacts on mammalian fauna. Overall, the temporal coverage is from the late Pleistocene to present (ca. 45,000 ybp to present). Estimates contained within this data set represent a generalized species value, averaged across gender and geographic space. Consequently, these data are not appropriate for asking population-level questions where the integration of body mass with specific environmental conditions is important. All extant orders of mammals are included, as well as several archaic groups (N = 4859 species). Because some species are found on more than one continent (particularly Chiroptera), there are 5731 entries. We have body masses for the following: Artiodactyla (280 records), Bibymalagasia (2 records), Carnivora (393 records), Cetacea (75 records), Chiroptera (1071 records), Dasyuromorphia (67 records), Dermoptera (3 records), Didelphimorphia (68 records), Diprotodontia (127 records), Hydracoidea (5 records), Insectivora (234 records), Lagomorpha (53 records), Litopterna (2 records), Macroscelidea (14 records), Microbiotheria (1 record), Monotremata (7 records), Notoryctemorphia (1 record), Notoungulata (5 records), Paucituberculata (5 records), Peramelemorphia (24 records), Perissodactyla (47 records), Pholidota (8 records), Primates (276 records), Proboscidea (14 records), Rodentia (1425 records), Scandentia (15 records), Sirenia (6 records), Tubulidentata (1 record), and Xenarthra (75 records). Data has undergone substantial data quality and assurance checking, though this is an on-going process. Histograms of the body masses of each order were produced, and values at the tails were double-checked for accuracy. When multiple sources of information were available for a species, or new sources encountered, we used those with higher sample sizes and gender-specific information. Headers are given here as header name followed by more information such as measurement units or other basic descriptor. More information on the variable definitions can be found in Section B, variable information (at http://www.esapubs.org/archive/ecol/E084/094/metadata.htm). Continent (SA, NA, EA, insular, oceanic, AUS, AF), Status (extinct, historical, introduction, or extant), Order, Family, Genus, Species, Log Mass (grams), Combined Mass (grams), Reference.

本数据集旨在收录全球所有哺乳动物的体重信息，以便我们研究地理、分类学空间以及演化时间跨度内的体重分布模式。我们关注不同分类类群间体型的遗传保守性（某一属、科、目内的体重保守性如何？）、各大洲间体重的整体分布模式（各大陆的体重矩及其他描述统计量是否保持一致？）以及随演化时间的变化规律（现今所见的体重模式演化速率如何？更新世灭绝事件在各大陆是否存在体型选择性？这些事件是否与人类抵达的时间相吻合？）。

本数据隶属于一项更大的研究计划，该计划旨在整合不同类群的体重分布模式——美国国家生态分析与合成中心（NCEAS）生态与古生态学生体型研究工作组：跨空间、时间与分类学尺度关联模式与过程。

我们以Wilson与Reeder（1993）更新版的全球现存哺乳动物分类名录（共4629个物种）为基础，补充了从一手及二手文献中整理得到的物种现状、分布范围与体重估算值。我们尽可能采用雌雄体重的平均值，并进一步对多个采样点的该平均值进行平均，以得到物种的体重数值。数据集的主要文献来源均已标注行号，完整参考文献见元数据中的附表。

哺乳动物的每条记录对应其栖息的一个大洲。需要说明的是，本数据集并非小型数据集的简单合并。尽管我们大量参考了K.E. Jones的翼手目（Chiroptera）数据集（共905条记录）、《CRC哺乳动物体重手册》（共688条记录）以及P. Marquet整理的南美哺乳动物数据集（共505条记录），但这三者的记录总数尚不足当前数据库总记录数的一半。剩余记录来自超过150个其他来源（详见参考文献附表）。此外，我们还补充了非洲、南北美及澳大利亚的完整晚更新世物种集合（新增230个物种）。“晚更新世”在非洲、南北美地区的定义为约11千年前，澳大利亚地区则为5万年前，因为该时间早于人类活动对哺乳动物区系造成影响的时期。整体时间覆盖范围从晚更新世至今（约45000年前至现代）。

本数据集收录的估算值为物种的通用体重值，已按性别与地理空间平均。因此，此类数据不适用于需要将体重与特定环境条件结合分析的种群层面研究。

本数据集涵盖所有现存哺乳动物目，以及数个已灭绝的古老类群，总计4859个物种。由于部分物种（尤其是翼手目）可栖息于多个大洲，因此总记录数为5731条。

本数据集包含以下类别的体重数据：偶蹄目（Artiodactyla，280条记录）、偏齿兽目（Bibymalagasia，2条记录）、食肉目（Carnivora，393条记录）、鲸目（Cetacea，75条记录）、翼手目（Chiroptera，1071条记录）、袋鼬目（Dasyuromorphia，67条记录）、皮翼目（Dermoptera，3条记录）、负鼠目（Didelphimorphia，68条记录）、双门齿目（Diprotodontia，127条记录）、蹄兔目（Hydracoidea，5条记录）、食虫目（Insectivora，234条记录）、兔形目（Lagomorpha，53条记录）、滑距骨目（Litopterna，2条记录）、象鼩目（Macroscelidea，14条记录）、微兽目（Microbiotheria，1条记录）、单孔目（Monotremata，7条记录）、袋鼹目（Notoryctemorphia，1条记录）、箭齿兽目（Notoungulata，5条记录）、粗毛负鼠目（Paucituberculata，5条记录）、袋狸目（Peramelemorphia，24条记录）、奇蹄目（Perissodactyla，47条记录）、鳞甲目（Pholidota，8条记录）、灵长目（Primates，276条记录）、长鼻目（Proboscidea，14条记录）、啮齿目（Rodentia，1425条记录）、树鼩目（Scandentia，15条记录）、海牛目（Sirenia，6条记录）、管齿目（Tubulidentata，1条记录）以及异关节总目（Xenarthra，75条记录）。

本数据集已开展大量数据质量与可靠性核查工作，该工作仍在持续进行中。我们绘制了各目哺乳动物体重的直方图，并对两端极值的准确性进行了复核。当某一物种存在多个信息来源或发现新来源时，我们优先选用样本量更大且包含性别细分信息的数据源。

数据集表头格式为“字段名+补充信息，如测量单位或其他基础描述符”。更多关于变量定义的细节可参见B节“变量信息”（网址：http://www.esapubs.org/archive/ecol/E084/094/metadata.htm）。字段包括：大洲（SA、NA、EA、海岛、远洋、AUS、AF，即南美洲、北美洲、欧亚大陆、海岛、远洋、澳大利亚、非洲）、物种现状（灭绝、历史记载种、引入种或现存种）、目、科、属、种、体重对数（克）、合并体重（克）、参考文献。