Personality underground: evidence of behavioral types in the solitary subterranean rodentCtenomys talarum

Abstract

Background: Animal personalities have been studied in a wide variety of taxa, but among rodents, available studies are relatively scarce and have focused mainly on social species. In this study, we evaluated the existence of personality in the solitary subterranean rodent Ctenomys talarum. Specifically, we aimed to test individual differences in behavior that are stable over time and context in males of C. talarum captured in the wild. Methods: Our experimental design included two series of three behavioral tests each, carried out with a 35 day time interval. Each series included an Open Field test, a Social Encounter test, and an Open Field test with a predator stimulus. Results: Of the total recorded behaviors, 55.55% showed temporal consistency. Principal component analysis of consistent behaviors grouped them into four dimensions that explain inter individual behavioral variability, in order of importance: activity, socioaversion, boldness and exploration. Therefore, our results suggest that the concept of animal personality is applicable to C. talarum and the dimensions found are in accordance with the ecological and behavioral characteristics of this species.

Self-Domestication Underground? Testing for Social and Morphological Correlates of Animal Personality in Cooperatively-Breeding Ansell’s Mole-Rats (Fukomys anselli)

“…Only the control trials (crossing the tunnel without obstacle) and the times an animal spent in close contact to the familiar conspecific in the affiliative behavior assay were not correlated for trial 1 and trial 2. In comparison, in Talas tuco-tucos, only about half of the recorded behaviors (55.5%) where temporally stable (Fanjul and Zenuto, 2020), and emotional behavior (e.g., OF test and dark-light test) in domestic guinea pigs was not consistent over time at all (Zipser et al, 2013). We expect that the time span of 4 weeks between experimental trials was sufficiently long for our subjects to forget about their former test experience.…”

“…Finally, it is noteworthy (compare e.g., Fanjul and Zenuto, 2020) that recorded behaviors relating to social encounters contributed to a higher degree to individual differentiation in Ansell's mole-rat personality than those concerned with activity (Figure 1A). Our results might be explained by the fact that while these animals are highly sociable, their activity levels are generally low (in captivity, up to 90% of the time is spent resting, Dammann and Burda, 2006;Schielke et al, 2012).…”

“…The current literature on animal personality considers five major temperament trait categories or personality dimensions: aggressiveness, boldness, exploration, activity, and sociability (Sih et al, 2004;Réale et al, 2007;Beckmann and Biro, 2013). Personality studies on rodents so far included species such as domestic guinea-pigs (Cavia porcellus - Zipser et al, 2013), bank voles (Myodes glareolus - Šěchová et al, 2014), ground squirrels (Urocitellus beldingi - Dosmann et al, 2015), and as a representative of the group of subterranean rodents, the Talas tuco-tuco (Ctenomys talarum - Fanjul and Zenuto, 2020). Individuals that show consistent behavior over time and across contexts for two or more behavioral traits are considered to have a personality.…”

“…Individuals that show consistent behavior over time and across contexts for two or more behavioral traits are considered to have a personality. However, in some studies only one of these criteria was met (and also just for some behaviors that have been studied) but the concept of animal personality was considered to apply to the species anyway (Zipser et al, 2013;Fanjul and Zenuto, 2020).…”