DOI: 10.5061/dryad.x0k6djht3
title: Plains zebra time budgets, social behavior, and communication during the 2021-2022 Laikipia-Samburu ecosystem drought

description: Anthropogenically induced climate change has significantly increased the
 frequency of acute weather events, such as drought. As human activities
 amplify environmental stresses, animals may be forced to prioritize
 survival over behaviors less crucial to immediate fitness, such as
 socializing. Yet, social bonds may also buffer organisms from the
 deleterious effects of environmental conditions. We investigated how the
 highly social plains zebra (Equus quagga) modify their activity budgets,
 social networks, and multimodal communication during a drought. This
 dataset contains a) activity budget, b) steps per minute as a proxy for
 foraging effort, c) nearest neighbor association data, d) interaction
 rate, e) juvenile social interaction partner data, and f) multimodal
 communication data.
description: <em>Ethical statement</em>
   This study was conducted on a
 population of wild plains zebras living in Ol Pejeta Nature Conservancy
 (0°00 N, 36°56 E), in Laikipia, Kenya. All research was conducted with the
 permission of Ol Pejeta Nature Conservancy and the Kenyan Ministry of
 Wildlife (NACOSTI/P/21/11647) and was in compliance with the guidelines of
 the Princeton University Institutional Animal Care and Use Committee
 (1835F).   <em>Study
 animals</em>   Our
 sample comprised 21 focal harems with an average harem size of 5 members
 (2-13 individuals) (Table S1). This population has been monitored
 continuously since 2008, and we have pedigrees of all focal individuals.
 We were able to individually identify zebras based on their unique
 stripes. Individuals were classified into one of four age/sex classes:
 stallion, non-lactating female, lactating female, and juvenile (Table S2).
 Juveniles were defined as pre-dispersal individuals, including
 pre-dispersed, sexually mature males as old as 4 years (N = 4 in 2021, N =
 2 in 2022), who are nonreproductive and still operate in the juvenile
 social niche (Klingel, 1965; personal observation).
   <em>Data
 collection</em>   Data
 collection occurred daily between July 13th and September 30th, 2021
 (hereafter “early drought”), and June 13th and August 12th, 2022
 (hereafter “late drought”). Two focal follows were conducted each day by
 vehicle, the first occurring between 08:00-12:00 and the second between
 12:30-16:30. A single harem was the subject of each observation period,
 and two harems were followed per day. At the beginning of each observation
 period, we recorded the presence or absence of members, including newly
 born foals, and scored the body condition of each individual using the
 plains zebra body condition scale, a qualitative measure of overall body
 condition (Ginsberg, 1988). Within each observation period, a single
 individual from the harem was selected as the focal animal, to be followed
 for two consecutive 30 minute blocks before a new focal individual was
 selected. The focal individual’s behavior was continuously captured using
 a Canon Vixia HR R700, and a Sennheiser ME66 directional microphone in a
 Rode Blimp windshield and a Tascam Dr-100MKII Linear PCM recorder sampling
 at 48kHz. As it is challenging to extract meaningful behavior from video
 recordings taken while the vehicle is in motion, if individuals engaged in
 continuous travel for an extended duration (&gt;15 continuous
 minutes), we terminated the video recording and manually recorded the
 start and end time of travel for later integration into time budget
 calculations. Between each 30-minute block, we conducted a scan sample of
 the entire harem and recorded the behavior and nearest neighbor of each
 member of the harem, operationalized as being within one body
 length.   All video was
 coded for behaviors of interest using ELAN video annotation software
 (version 4.8.1). To investigate changes in activity budget across years,
 we coded 1 to 3 equally spaced five-minute sub-samples from each video
 (i.e. 5-10 minutes, 15-20 minutes, 25-30 minutes), depending on the video
 length. We scored nearest neighbor of the focal animal every five minutes.
 Within the sub-samples, we counted steps-per-minute. We also scored all
 activities performed by the focal animal during the sub-samples to
 construct time budgets (Table 2). Social behaviors were grouped into two
 broad categories, “passive socializing”, which were defined as
 proximity-based social behaviors produced concurrently with a
 self-maintenance behavior (i.e. resting in physical contact, grazing
 side-by-side), and “active socializing”, which included dedicated social
 behaviors with no additional self-maintenance function (e.g. aggression,
 affiliation, etc.).   To
 analyze multimodal communication, we coded all interactions captured by
 our focal follow videos. Our coding scheme is published in detail
 elsewhere (Hex & Rubenstein, 2024). In brief, we coded all
 concurrent visual, acoustic, tactile, and/or chemical signals produced. An
 interaction was defined as beginning when two individuals entered one body
 length of one another and the sender was 1) oriented towards the receiver,
 2) the signal was produced in the direction of the receiver, 3) the sender
 approached the receiver, and/or 4) the sender made physical contact with
 the receiver. An interaction was defined as terminated when either 1) one
 individual moved beyond one body length of the other without being
 followed, or 2) the parties ceased interacting for at least 10 seconds
 (e.g., began to graze or sleep in proximity).
   We only coded interactions in which
 the video was zoomed in enough for reliable coding of all areas of
 interest, and in which the focal individual was in focus and entirely in
 frame, unobscured by foliage or non-focal animals. We eliminated 263
 interactions from early drought and 118 interactions from late drought
 which did not meet this criterion. To improve the interpretability of our
 results, we cleaned our data prior to analysis by removing multimodal
 postures containing a component observed in fewer than two interactions.
 After cleaning, we were left with 336 high quality interactions comprising
 1,461 multimodal postures for early drought, and 115 interactions
 comprising 439 multimodal postures for late drought.
  
 <em>References</em>
   Ginsberg, J.R. (1988). Social
 organization and mating strategies of an arid-adapted ungulate: the
 Grevy’s zebra. [Doctoral dissertation, Princeton University].
   Hex, S. B., Rubenstein, D. I. (2024).
 Using networks to visualize, analyse and interpret multimodal
 communication. Anim. Behav. 207, 295-317.
description: # Plains zebra time budgets, social behavior, and communication during the
 2021-2022 Laikipia-Samburu ecosystem drought This dataset comprises the
 activity budgets, social association data, social interactions, and
 multimodal communication of wild plains zebras(Equus quagga) collected in
 the summers of 2021 and 2022, during which time a severe drought was
 experienced in the Laikipia-Samburu ecosystem. Data were collected from
 videos collected during focal follows of 21 known focal harems, from which
 we extracted social and self-maintenance behaviors, steps-per-minute, rate
 of social interaction, nearest-neighbor association data, and social
 interactions. Multimodal communication was coded from videos to define the
 full suite of visual, acoustic, tactile, and chemical signals being
 produced. Data were subsequently used to construct co-occurrence networks
 of multimodal communication. **Description of data and file structure**
 All datasets have a "Key" tab with definitions of the columns
 and their units. Dataset S1. Complete dataset used to construct plains
 zebra time budgets for 2021 and 2022. For a subset of data, Begin time and
 End time have an "na" value. These were manually recorded travel
 bouts. As it is challenging to extract meaningful behavior from video
 recordings taken while the vehicle is in motion, if individuals engaged in
 continuous travel for an extended duration (&gt;15 continuous minutes), we
 terminated the video recording and manually recorded the duration of
 travel for later integration into time budget calculations.  Dataset S2.
 Complete dataset used to calculate steps/minute for 2021 and 2022. Dataset
 S3. Complete dataset of focal follow nearest neighbor scan samples for
 2021 and 2022. Empty cells in Nearest2 column are equivalent to an N/A,
 meaning there was no second individual within one body length of the focal
 individual. Dataset S4. Complete dataset of full harem nearest neighbor
 scan samples for 2021 and 2022. Empty cells in the Nearest column
 are equivalent to an N/A, meaning there was no individual within one body
 length of the focal individual. Dataset S5. Complete dataset of
 interactions/30 minutes for 2021 and 2022. Dataset S6. Complete dataset of
 juvenile social interaction partners 2021 and 2022. Dataset S7. Complete
 dataset used to construct plains zebra multimodal communication networks
 for 2021 and 2022. Dataset S8. Body condition scores of individuals in
 2021 and 2022. Each row represents an observed configuration of visual,
 tactile, acoustic, and/or chemical signals seen in a given moment in time.
 "Begin_Time" and "End_Time designate the time in the video
 that the given configuration was observed, while "Duration"
 designates how long the given posture was observed. All three are in
 "hh:mm:ss" format. The entire body, "Ears",
 "Eyes", "Upper_Lip", "Corner_of_Lip",
 "Jaw", "Head_Neck_Position", and "Tail" are
 represented for each posture except for instances where there were
 mutually exclusive or redundant states (e.g. "jaw open" and
 "bite"). All other potential components were coded only as
 observed, and therefore may not be present in every observation. R Code
 S1. R code used to conduct all analyses and construct all visualizations.