Reproductive state affects hiding behaviour under risk of predation but not exploratory activity of female Spanish terrapins

Abstract

Female investment during reproduction may reduce survivorship due to increased predation risk. During pregnancy, the locomotor performance of gravid females might be diminished due to the additional weight acquired. In addition, egg production may also increase thermoregulatory, metabolic and physiological costs. Also, pregnant females have greater potential fitness and should take fewer risks. Thus, females should ponder their reproductive state when considering their behavioural responses under risky situations. Here, we examine how reproductive state influence risk-taking behaviour in different contexts in female Spanish terrapins (Mauremys leprosa). We simulated predator attacks of different risk levels and measured the time that the turtles spent hiding entirely inside their own shells (i.e. appearance times). We also assessed the subsequent time after emergence from the shell that the turtles spent immobile monitoring for predators before starting to escape actively (i.e. waiting times). Likewise, we performed a novel-environment test and measured the exploratory activity of turtles. We found no correlations between appearance time, waiting time or exploratory activity, but appearance times were correlated across different risk levels. Only appearance time was affected by the reproductive state, where gravid females reappeared relatively later from their shells after a predator attack than non-gravid ones. Moreover, among gravid females, those carrying greater clutches tended to have longer appearance times. This suggests that only larger clutches could affect hiding behaviour in risky contexts. In contrast, waiting time spent scanning for predators and exploratory activity were not affected by the reproductive state. These differences between gravid and non-gravid females might be explained by the metabolic-physiological costs associated with egg production and embryo maintenance, as well as by the relatively higher potential fitness of gravid females.

Ontogenetic shift of antipredator behaviour in Hermann’s tortoises

“…The decision on when to shift from one strategy to another entails a set of costs and benefits. While withdrawn in its protective armour, an individual may benefit from safety but simultaneously may suffer certain costs: giving the predator more time to overpower their cover, succumb Communicated by T. Madsen to suboptimal environmental conditions or miss opportunities for foraging or mating (Mima et al 2003;Polo-Cavia et al 2008;Ibáñez et al 2014Ibáñez et al , 2015.…”

Melanin‐Based Coloration Covaries with Hiding and Exploratory Behavior in Male Spanish Terrapins

“…; Ibáñez et al. , ). An increase of exploratory behavior in a novel environment should enhance faster assessment of potential risks in the environment where the individual is found (Rodríguez‐Prieto et al.…”

“…; Ibáñez et al. , ). In this context, the relation between melanin and behavioral traits should depend on the risk level assessed by the turtles.…”

Effects of human disturbance on risk‐taking behavior in painted turtles

“…Indeed, the propensity to take risks has been explored in turtles using various behavioral measurements. Diverse measures of latencies (e.g., latency for the head to emerge from the shell, latency to move) following a confinement or a simulated predator attack have been used as proxies for risk‐taking propensity in several turtle species (Eastern box turtles Terrapene carolina , Carlson & Tetzlaff, 2020; Kashon & Carlson, 2018; Pich et al, 2019; Painted turtles Chrysemys picta , Roth et al, 2020; Red‐eared slider turtles Trachemys scripta , Carter et al, 2016; Spanish terrapins Mauremys leprosa , Ibáñez et al, 2018; Ibáñez et al, 2013; Ibáñez et al, 2015). In particular, Pich et al (2019) assessed risk‐taking propensity in Eastern box turtles by adding the number of active defensive behaviors used during a simulated predator attack.…”