Guanaco distribution modeling in the last 2500 years in Northwest Patagonia

Context: The guanaco is one of the four species of South American camels, and is the largest native mammal inhabiting arid and semi-arid environments in South America. Although guanaco was abundant and widely distributed in the past, currently its density and distribution range are substantially reduced, inhabiting mainly in Argentine Patagonia in small isolated groups. The decline in guanaco populations is most likely related to the Anthropocene defaunation process that is affecting large mammals in developing countries worldwide, but the extent and causes of these changes are not well understood.
Aims: Explore both the changes in the distribution of guanaco populations in Northwest Patagonia and the environmental and anthropic factors that shaped the distribution patterns, employing a long-term perspective spanning from the end of the Late Holocene to present times (i.e., last 2500 years).
Methods: We combine archaeological information, ethnohistorical records and current observations..., We collected guanaco occurrences from archaeological, ethnohistorical and current sighting data, and separate this data in periods (Lata Holocene, Historic and Current). Likewise, different bioclimatic and anthropic variables that could contribute to explain guanaco distribution in Northwest Patagonia were collected. Finally, the R script to model guanaco distribution in each period and estimate the explicatory power of each variable is also upload., , # Guanaco Distribution Modeling in the last 2500 years in Northwest Patagonia

Here are guanaco (*Lama guanicoe*) occurrences that we collected from archaeological, ethnohistorical and current sighting data from Northwest Patagonia (Argentina), separated in periods (Lata Holocene, Historic and Current). Likewise, we also provide different bioclimatic and anthropic variables that could contribute to explain guanaco distribution in Northwest Patagonia, as well as the R script to model guanaco distribution in each period and estimate the explicatory power of each variable. We found significant changes in guanaco distribution throughout time. Specifically, in the Current period (last 30 years of sightings) guanaco distribution shifted to the East, and the main explanatory variables are Human footprint and herders summer camps.

## Description of the data and file structure

The files upload are:

* 3 csv files which contain the guanaco occurrences for the three periods considered, Late ...

背景：原驼（guanaco）是南美骆驼科的四个物种之一，也是栖息于南美干旱与半干旱环境中的最大本土哺乳动物。尽管历史上原驼种群数量充沛、分布广泛，但当前其种群密度与分布范围已大幅缩减，目前主要以小型孤立种群的形式栖息于阿根廷巴塔哥尼亚地区。原驼种群的衰退大概率与影响全球发展中国家大型哺乳动物的人类世（Anthropocene）动物区系衰减过程相关，但这类变化的程度与成因目前尚未得到充分阐释。

研究目标：以从晚全新世末期至今（即过去2500年）的长期视角，探究巴塔哥尼亚西北部原驼种群分布的变化，以及塑造其分布格局的环境与人为因素。

研究方法：本研究整合考古资料、民族史记录与现代观测数据，从考古、民族史与现代目击数据中收集原驼出现记录，并将其划分为晚全新世、历史时期与现代时期三个阶段。同时，本研究还收集了可用于解释巴塔哥尼亚西北部原驼分布的各类生物气候与人为变量。此外，用于模拟各时期原驼分布、并估算各变量解释能力的R脚本也已同步上传。

# 巴塔哥尼亚西北部过去2500年原驼分布建模

本数据集包含从阿根廷巴塔哥尼亚西北部的考古、民族史与现代目击数据中收集的原驼（*Lama guanicoe*）出现记录，并按晚全新世、历史时期与现代时期三个时期进行划分。同时，本数据集还提供了可用于解释巴塔哥尼亚西北部原驼分布的各类生物气候与人为变量，以及用于模拟各时期原驼分布、估算各变量解释能力的R脚本。

研究发现，原驼的分布格局随时间发生了显著变化。具体而言，在现代时期（即过去30年的目击记录阶段），原驼的分布范围向东迁移，其主要解释变量为人类足迹与牧民夏季营地。

数据与文件结构说明：
本次上传的文件包括：
* 3个CSV格式文件，分别存储所研究三个时期的原驼出现记录，晚[...]