jwturn / hyenaearlyrelationshipsfitness

:notebook: Scripts and data for Early life relationships matter: Social position during early life predicts fitness among female spotted hyenas

Early life relationships matter: Social position during early life predicts fitness among female spotted hyenas

• Authors:
  • Julie W. Turner
  • Alec L. Robitaille
  • Patrick S. Bills
  • Kay E. Holekamp

This repository contains the data and code accompanying the paper “Early life relationships matter: Social position during early life predicts fitness among female spotted hyenas”.

Abstract

1. How social development in early life affects fitness remains poorly understood.

2. Though there is growing evidence that early-life relationships can affect fitness, little research has investigated how social positions develop or whether there are particularly important periods for social position development in an animal’s life history. In long-lived species in particular, understanding the lasting consequences of early-life social environments requires detailed, long-term datasets.

3. Here we used a 25-year dataset to test whether social positions held during early development predicted adult fitness. Specifically, we quantified social position using three social network metrics: degree, strength, and betweenness. We determined the social position of each individual in three types of networks during each of three stages of ontogeny to test whether they predict annual reproductive success (ARS) or longevity among adult female spotted hyenas (Crocuta crocuta).

4. The social positions occupied by juvenile hyenas did predict their fitness, but the effects of social position on fitness measures differed between stages of early development. Network metrics when individuals were young adults better predicted ARS, but network metrics for younger animals, particularly when youngsters were confined to the communal den, better predicted longevity than did metrics assessed during other stages of development.

5. Our study shows how multiple types of social bonds formed during multiple stages of social development predict lifetime fitness outcomes. We suggest that social bonds formed during specific phases of development may be more important than others when considering fitness outcomes.

Data

Data included are the calculated social network metrics, randomizations, and other variables used in the models in scripts 7-8. Descriptions of the variables in the data for analysis are below.

variable	description
ego	focal female for analyses
period	cd (communal den)
ego_period_rank	ego’s rank during that period
mom	ego’s mother
clan_size	number of individuals in the clan during stated period for that ego
nSession	number of sessions the ego was observed in during that period
alone	alone rate
sri_degree	degree centrality of the ego during that period based on the association network (simple ratio index)
sri_strength	stength of the ego during that period based on the association network (simple ratio index )
sri_betweenness	betweenness of the ego during that period based on the association network (simple ratio index)
aggr_outdegree	out-degree centrality of the ego during that period based on the aggression network
aggr_indegree	in-degree centrality of the ego during that period based on the aggression network
aggr_outstrength	out-stength of the ego during that period based on the aggression network
aggr_instrength	in-stength of the ego during that period based on the aggression network
aggr_betweenness	betweenness of the ego during that period based on the aggression network
affil_outdegree	out-degree centrality of the ego during that period based on the affiliation network
affil_indegree	in-degree centrality of the ego during that period based on the affiliation network
affil_outstrength	out-stength of the ego during that period based on the affiliation network
affil_instrength	in-stength of the ego during that period based on the affiliation network
affil_betweenness	betweenness of the ego during that period based on the affiliation network
longevity_years	age in years when the ego died
annual_rs	annual reproductive success (ARS) for the ego
iteration	iteration of the randomizations
observed	TRUE - the data comes from observations; FALSE - the data comes from randomizations