Staying Alive: Individual Behavioral Variation Influences Survival, but Not Reproductive Success, in Female Group‐Living Ground Squirrels

TL;DR

The study found that individual behaviors like docility and boldness in female Cape ground squirrels affect their survival but not their reproductive success.

Contribution

This study is novel in showing that behavioral traits influence survival but not reproductive success in wild female ground squirrels.

Findings

Docile females had higher annual survival rates.

Bolder females also had higher annual survival rates.

Behavioral traits did not correlate with reproductive success in females.

Abstract

Animals living in harsh or unpredictable environments adopt adaptive strategies to improve their fitness, with behavioral variation playing a key role in shaping individual outcomes. We examined whether between‐individual variation in behavioral traits (personality) was associated with reproductive success and survival in female Cape ground squirrels (
Xerus inauris
). Using a 10‐year dataset (2011–2021), we quantified behavioral expressions of the animal's response to trapping and handling (trap response, as a proxy for docility), trapping rate (trappability, for boldness) and the number of different trapping locations an animal was trapped at (trap diversity, for exploration) and examined their associations with (1) annual reproductive success, (2) lifetime reproductive success, (3) annual survival, and (4) on‐site persistence (a proxy for lifespan). Response measures taken during transfer from the cage, handling by a human observer, and whether individuals ran or walked after release were moderately repeatable. Trappability was also repeatable, while trap diversity was not. Trap response and trappability were positively correlated with survival, but not reproductive success. Females that easily transferred from the trap to the handling bag (more docile) had higher annual survival, while those that ran after release had longer lifespans. Individuals trapped at a higher rate (bolder) had higher annual survival. The absence of a relationship between behavioral traits and reproductive success in females suggests that other factors, such as group dynamics, social interactions, and maternal effects, may be more influential in explaining the high reproductive skew in female reproductive success. Overall, our findings highlight the role of individual behavioral variation in shaping survival outcomes while emphasizing the need for further research into the mechanisms driving reproductive success in this species.

We investigated how individual behavioural traits—docility and boldness—affect survival and reproductive success in female Cape ground squirrels over a ten‐year period. While both traits influenced survival, with more docile and bolder individuals showing higher annual survival, neither trait predicted reproductive success. These findings suggest behavioral variation supports survival but that other factors likely drive reproductive outcomes in this species.

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