DOI: 10.5061/dryad.z612jm6p2
title: Data from: Baboon travel progressions as a ‘social spandrel’ in collective animal behaviour

description: How individuals in a group move relative to one another can influence both
 their survival and fitness. Spatial positioning has been well studied in
 baboons (Papio spp.), which travel collectively in line formations called
 "progressions". Early studies of baboon progressions presented
 contradictory findings – some reporting random positioning of individuals,
 and others reporting non-random positioning, thought to protect more
 vulnerable group members. Here, we revisit this topic and use
 high-resolution GPS tracking data to study a chacma baboon (Papio ursinus)
 group’s travel progressions on the Cape Peninsula, South Africa. We
 identify 78 progressions over 36 days and find that progression orders are
 not random. We test four non-exclusive hypotheses to explain progression
 orders: vulnerable individuals position themselves in the middle of the
 progression (risk hypothesis), subordinate individuals position themselves
 at the front to gain better access to resources (competition hypothesis),
 dominant individuals assume leading positions (group decision-making
 hypothesis), or progression order is an emergent outcome of underlying
 social bonds (social spandrel hypothesis). We find no evidence that
 progression orders are adaptive responses to minimise an individual’s
 risk, maximise their resource acquisition, or are the result of
 decision-makers leading the group. Instead, we find that individuals’
 positions are predicted by pairwise affiliations and social dominance,
 with more dominant individuals occupying central positions in
 progressions. This non-random structuring of individuals during
 progressions can be considered a side-effect or outcome of underlying
 social forces acting among the individuals, providing an example of a
 ‘social spandrel’ in collective animal behaviour.
description: # Baboon travel progressions as a ‘social spandrel’ in collective animal
 behaviour Data for the group progression is contained in
 progresion_data.csv. ## Description of the data and file structure |
 **Column Name** | **Description** | |
 --------------------------------------------- |
 -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `id` | Unique identifier of the baboon individual (e.g., "Azul", "Cindy") for each row. | | `lon` | Longitude coordinate (in projected units, likely UTM or local coordinate system). | | `lat` | Latitude coordinate (in projected units, matching the system used for `lon`). | | `dateTime` | Date and time when the data point was recorded, in `DD-MM-YYYY HH:MM` format. | | `event` | Event identifier; may indicate a unique interaction or sampling event (e.g., event 44). | | `duration` | Duration of the event or observation in seconds (e.g., 288 seconds = 4.8 minutes). | | `[Names]` (e.g., `Azul`, `Cindy`, `Don`, ...) | Pairwise proximity or interaction values between the focal individual (`id`) and others in the group. The values likely represent **distances in meters** or **interaction strength**. "NA" indicates no data or no interaction. | | `component` | Network component ID; individuals sharing the same component are part of a connected group during the event. | | `component_size` | Number of individuals in the component the focal individual belongs to. | | `numInd` | Total number of individuals detected or recorded during the event. | | `date` | Date of the event in `DD-MM-YYYY` format. Duplicates part of `dateTime`. | | `time` | Time of the event in `HH:MM:SS` format. Duplicates part of `dateTime`. | ## Code/Software The code to analyze the data can be found at [GitHub](https://github.com/MarcoFele98)