Social rank, female competition for food, and behavioural time-budgets in a temperate primate multi-level society
Data files
Feb 19, 2025 version files 155.19 KB
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Foodstack_all.xlsx
69.42 KB
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README.md
9.16 KB
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Timebudget_all.xlsx
76.61 KB
Abstract
Competition within primate groups often translates to a social hierarchy, with high-rank individuals gaining privileged access to resources, especially food. Golden snub-nosed monkeys Rhinopithecus roxellana live in a multi-level society, with multiple one-male units (OMUs), each containing a single adult male and several females, forming a breeding-band. High-rank males have increased access to high-value foods and spend less time feeding and more time being groomed by females, potentially enhancing social cohesion within their OMUs. The adults of each OMU mainly feed and socialize together, with food competition predominantly acting at the OMU level. We thus predicted that adult females by association attain the rank and feeding privileges of their OMU leader males, and make similar time-budget trade-offs. By food-provisioning a wild breeding-band during winter and spring, when natural foods are abundant or limited, respectively, we found that females of high-rank OMUs ate more provisioned foods at higher rates, especially during winter when provisioned foods had increased value. In winter, females of low-rank OMUs fed for longer on natural foods and females of high-rank OMUs longer on provisioned foods. Females of high-rank OMUs spent longer being groomed by other OMU members, especially during winter. Our results are consistent with females attaining the feeding privileges of their OMU leader male, enhanced during winter due to increased value of provisioned foods, high thermal demands, and reduced natural food availability. Importantly, the feeding privileges attained by females of high rank OMUs were less pronounced than those previously found for leader males, possibly due to higher tolerance between females of different OMUs. We suggest that behavioral time-budget effects of food competition in female R. roxellana enhance cohesion in high-rank OMUs, contributing to OMU integrity and, hence, the social structure of this multi-level society.
Spreadsheet column headings
Foodstack data sheet
This spreadsheet is made up of values taken in spring and winter by recording the same group of monkeys. The values have also been split between two food types, provisioned and natural. This is to enable the comparison of food type and season. However, this results in data from the same individual females being included because measurements were taken from the same monkeys in spring and winter, and because they eat both provisioned and natural food on the same day. These data for the same monkeys have thus been ‘stacked’ on top of each other. This has been accounted for in our statistical analysis by using ‘individual’ as a random factor
‘Day’ of data recording reflects the same ‘date’ in each dataset. ‘Rank’ is the OMU leader male rank at the time the data were recorded.
Column headings and what they mean.
Number – row number. To enhance data sorting and management.
Season – winter or spring. This column is used to differentiate between seasons.
Date – the date on which the data for the row were recorded.
Day – from the first through to the last, this is day in words. The total equals the number of days data were recorded. This enables ‘day’ to be used as a random factor in mixed models.
Am temp – air temperature before morning data recording.
Pm temp – air temperature before afternoon data recording.
Observer – the student who recorded the data for the particular row.
Individual – the individual adult female whose behaviour is being recorded for this row of data.
OMU – the OMU (individual OMU leader male) to which the individual female belongs
OMU size – the number of adult females within the foacl female’s OMU at the time of sampling
Rank – the rank on the OMU leader male to which the individual female belongs (as determined by David’s score data).
Food - the food the data for the particular row the female was consuming during the time of recording, either provisioned or natural. The same individual eats both provisioned and natural foods each day so the data have to be partitioned between the two food types. We therefore have two data rows for each individual for each recording day, one for provisioned food and the other for natural food.
Feeding – the time in hours the particular individual spent feeding on both provisioned and natural foods.
Tottime – the total time the individual had its behaviour recorded on the day of recording.
Foodtime – the time the individual spent feeding on the food type in ‘food’. Food time for ‘provisioned’ + foodtime for ‘natural’ therefore = ‘feeding.’
Food_g – the mass in g of food consumed by the individual during the day of recording for the particular food type indicated by ‘food.’ So we have two measures for each recording of an individual monkey, one for provisioned and another for natural.
**Food_jk **– energy intake for the food type ingested as designated in ‘food.’ There are thus two measures each on different rows per monkey, one for provisioned and another for natural.
Propfeedtime – the proportion of time spent feeding on food of the particular food type designated in ‘food’ of the total time spent feeding for that day’s recording: Foodtime/feeding. Propfeedtime for provisioned + propfeedtime for natural therefore = feeding.
Feedrate – the amount of foodg (of the type designated in ‘food’) consumed per unit time, out of the total time the monkey was feeding that day: food_g/feeding.
Propfeedtimearc – arcsine square root transformation of ‘propfeedtime.’
Logfood g – log(10) values of Food_g
Logfeedrate – log10 transformation of ‘feedrate.’
Feedmin – total time spent feeding ‘feeding’ in minutes. This creates a vector of integers.
Foodmin – total time spent feeding on a food type, either provisioned or natural, ‘foodtime’ in minutes.
Totmin – total daily recording time ‘tottime’ in minutes.
Time budget data sheet
The data concern different behaviours exhibited by focal female individuals during each day’s data recording.
Number – row number. To enhance data sorting and management.
Season – season data were recorded either spring or winter
Date – date when data sere recorded
Morning temperature - air temperature in the morning before recording began
Sunset temperature – temperature in afternoon
Temperature difference – difference between morning and sunset temperature
Observer – code for the person who recorder the values for this row of data
Individual – the individual female whose behaviour has been recorded
Sex –The sex of the focal individual, here (AF) all are female
Unit – the code for the OMU leader male of the OMU to which the focal female ‘individual’ is a member.
OMU size – the number of adult females within the same OMU as the focal female
Rank – OMU leader male rank as determined by David’s score: rank at the time data were recorded
Feeding – the time in hours the focal monkey spent feeding during that day’s recording.
Not_feed – the time spend during the day’s data recording by the focal monkey on activities other than feeding. Feeding + not_feed therefore = total observation time.
Prop_feed – the proportion of all time the focal monkey spent feeding; prop_feed = Feeding/(feeding + not_feed)
Asin_feed – prop_feed transformed to acrsine square root
Moving – time spent moving in hours
Not_move – time spent on all activities other than moving
Prop_more – proportion of all time spent moving
Asin_move – arcsine square root transformation of prop_move
Resting – time spent resting in hours
Not_rest – time spent on all activities other than resting
Prop_rest – proportion of all time recorded that day spent resting
Asin_rest – arcsine square root transformation of prop_rest
Groomer – time spent grooming other individuals (usually within the same OMU)
Not_groomer – time spent on other activities other than grooming other individuals
Prop_groomer – proportion of all time spent grooming other individuals
Asin_groomer – arcsine square root transformation of prop_groomer
Groomed – time individual spent being groomed by another individual
Not-groomed – time spent on activities other than being groomed by another individual
Prop_groomed – proportion of all time being groomed by another individual
Asin_groomed – arcsine square root transformation of prop_groomed
Attack – proportion time spent involved in attacking other OMUs
Not_attack – time spent not attacking other OMUs
Prop_attack – proportion of all time spent attacking other OMUs
Asin_attack – arcsine square root transformation of prop_attack
mating – proportion time spent mating
Not_mating – time spent not mating
Prop_mating – proportion of all time spent mating
Asin_mating – arcsine square root transformation of prop_mating
embracing – proportion time spent embracing or being embraced by other individuals
Not_embracing – time spent not embracing or being embraced by other individuals
Prop_embracing – proportion of all time spent embracing or being embraced by other individuals
Asin_embracing – arcsine square root transformation of prop_embracing
Social+ - time spent engaged in social behaviours (grooming, being groomed, and embracing). NB mating not included as time is minimal.
Not_social – time spent on behaviours spent on non-social activities: i.e. tottime – social+
Prop_non_social – proportion of all time spent on non-social behaviours
Asin_non_social – arcsine square root transformation of prop_non_social
Prop_social – proportion of all time spent on social behaviours
Asin_social – arcsine square root transformation of prop_social
Tottime – time in hours spend recoding the focal monkey that day
Feed_prov – time in hours spent feeding on provisioned food
Feed_nat – time spent feeding on natural food
Prop_prov_feed – proportion of tottime spent feeding on provisioned food
Pr_feedarc – arsine square root transformation of prop_prov_feed
Prop_nat_feed – proportion of tottime spent feeding on natural food
Nat_feedarc – arsine square root transformation of prop_nat_feed
Prov_feed – duplicate of feed_prov
Nat_feed – duplicate of feed_nat
Field study of female-female competition in wild golden monkeys. The effects of seasonality and social rank were tested. Data are arranged in order to be analysed in R using mixed-models.