An early-life challenge: becoming an older sibling in wild mandrills

In monotocous mammals, most individuals experience the birth of a younger sibling. This period may induce losses in maternal care and can be physiologically, energetically and emotionally challenging for the older sibling, yet has rarely been studied in wild primates. We used behavioural data collected from a natural population of mandrills to investigate changes in maternal care and mother-juvenile relationship throughout the transition to siblinghood (TTS), by comparing juveniles who recently experienced the birth of a younger sibling, to juveniles who did not. We found that the TTS was associated with an abrupt cessation of the weaning process for the juvenile, and to a decrease in maternal affiliation. Juveniles’ reactions were sex-specific, as males associated less with their mother, while females tended to groom their mother more often after the birth of their sibling. Despite the substantial loss of maternal care juveniles did not show an increase in conflict or anxiety-related b..., , , # An early-life challenge: becoming an older sibling in wild mandrills

[https://doi.org/10.5061/dryad.7wm37pw25](https://doi.org/10.5061/dryad.7wm37pw25)

## Description of the data and file structure

Data used to run all models presented in the article can be found in \"Data_TTSMandrills_vGitHub.xlsx\".The file contains several sheets, each labeled with the model number for which the dataset in the given sheet should be used. The last sheet contains a legend of the variables in each dataset. Note that in the R code, the different datasets are loaded as individual .csv files, so each excel sheet will need to be converted into a .csv file before running the code. 

The code used to run the models can be found in \"Script_TTSmandrills_Analyses_vGitHub.R\" (Zenodo)

## Sharing/Access information

All data and code can also be found here:

* [https://gitlab.com/AxelleDelaunay/transition-to-siblinghood-in-mandrills](http://...)

# 一项早期生命挑战：野生山魈（mandrill）的兄姐身份转变

在单胎哺乳动物类群中，多数个体都会迎来幼弟或幼妹的降生。这一时期会导致母育照料资源的缩减，对年长幼崽造成生理、能量与情绪层面的多重挑战，但目前针对野生灵长类的相关研究仍极为匮乏。本研究以自然种群中山魈的行为数据为基础，通过对比近期刚迎来同胞幼崽的年长幼崽与未经历该事件的同龄个体，探究幼崽向兄姐身份转变（transition to siblinghood, TTS）过程中母育照料与母幼关系的动态变化。

本研究发现，TTS与幼崽断奶过程的突然终止以及母幼联结强度的下降显著相关。幼崽的反应存在显著性别差异：雄性幼崽与母兽的互动频次显著降低，而雌性幼崽在同胞降生后会更频繁地为母兽梳理毛发。尽管母育照料出现了显著缩减，但幼崽并未表现出冲突或焦虑相关行为的增加……

[https://doi.org/10.5061/dryad.7wm37pw25](https://doi.org/10.5061/dryad.7wm37pw25)

## 数据与文件结构说明

本文所有模型运行所需的数据均收录于"Data_TTSMandrills_vGitHub.xlsx"文件中。该文件包含多个工作表，每个工作表均标注有对应的模型编号，即该工作表内的数据集仅适用于对应编号的模型。最后一个工作表为各数据集的变量说明表。需注意，在R代码中，不同数据集需以独立的.csv文件形式加载，因此在运行代码前，需将每个Excel工作表转换为.csv格式文件。

模型运行代码收录于"Script_TTSmandrills_Analyses_vGitHub.R"（Zenodo平台）

## 共享与获取信息

所有数据与代码亦可通过以下链接获取：
* [https://gitlab.com/AxelleDelaunay/transition-to-siblinghood-in-mandrills](http://...)