African Striped Mouse Rhabdomys Pumilio Research Articles

Survival is linked with reaction time and spatial memory in African striped mice.

Studying the association between fitness and cognition in free-living animals is a fundamental step in the elucidation of the evolution of cognition. We assessed whether survival until the onset of the breeding season was related to reaction time or spatial memory in the African striped mouse Rhabdomys pumilio, a rodent that has to survive summer drought before breeding. We tested a total of 90 individuals at the beginning of summer. Female survival was related to a faster response to predation stimuli. Male survival increased with greater spatial memory, possibly because it is important for males to remember the configuration of the environment during dispersal. This study revealed that individual variation in reaction time and spatial memory can be related to survival probability, which is important for understanding the selection pressures acting on basic cognitive traits.

Interactive effects of exogenous and endogenous factors on demographic rates of an African rodent

Exogenous and endogenous environmental factors can have simultaneous additive as well as interacting effects on life‐history traits. Ignoring such interactions can lead to a biased understanding of variability in demographic rates and consequently population dynamics. These interactions have been the focus of decades‐long debates on the mechanisms underlying small mammal population fluctuations. They have often been studied indirectly through seasonal effects, but studies considering them directly and more mechanistically are rare. We investigated the joint effects of exogenous (temperature, food availability) and endogenous (population density) factors on the demographic rates of a group‐living diurnal rodent, the African striped mouse Rhabdomys pumilio using nine‐year mark–recapture data from a population in the Succulent Karoo, South Africa. In general, higher temperatures and lower food availability were associated with higher survival, whereas high population densities were either beneficial or detrimental to survival depending on interacting food availability. High reproductive rates were related to lower temperatures, higher food availability and lower population density, and interactions among environmental factors mediated the strength of these relationships. Our study highlights the complex ways in which different environmental factors can interact to shape demographic rates and emphasizes the importance of explicitly including interactions among exogenous and endogenous factors into studies of population dynamics.

Does a mouse have a friend? Mixed evidence for individual recognition in the African striped mouse (Rhabdomys pumilio)

AbstractIndividual recognition, the ability to discriminate between members of a social group according to their distinctive characteristics, is a sophisticated form of social recognition. Several laboratory studies demonstrated individual recognition in rodents, but not under natural conditions. We combined behavioral observations and an experiment to assess individual recognition in free‐living African striped mice Rhabdomys pumilio. Striped mice live in groups that share a nest, but forage alone during the day. Interactions among group members are typically amicable and take place at the nest. In order to determine whether striped mice have individualized relationships, we analyzed whether focal mice interacted repeatedly more often with one specific group member. Data from 58 focal individuals from 15 groups revealed that the individual with which amicable interactions occurred the most was often alone in one mode of the data distribution, indicating that behavior toward this specific individual differed compared to the behavior to all other group members. Striped mice consistently preferred this specific individual during the following weeks. Preferred social partners of both breeders and younger non‐breeders were young non‐breeders. Sex‐specific effects were obtained only for young adult males and breeding females, which both associated more often with the opposite sex. For 11 young adults from 11 groups, the preferred social partner was trapped and removed, either overnight (experiment) or only during the day (control), when striped mice forage solitarily and usually do not interact with group members. Striped mice interacted on average more with their preferred social partner after it returned in the experimental group compared to the control (7 of 11 experiments), but the difference was not significant (P = 0.16). Our study indicates that striped mice might have individualized relationships, although they failed to significantly indicate individual recognition during experimental removals. Future studies will have to test the adaptive function of individualized relationships in African striped mice.

Female mate choice for paternal care behaviour in African striped mice Rhabdomys pumilio: the role of experience

AbstractPaternal care is a behavioural characteristic that can be selected for by females. By preferentially mating with 'good' fathers, females may directly increase their own reproductive success and may indirectly increase the prevalence of this trait in their sons. We investigated female mate choice in naturally paternal desert-dwelling African striped mice Rhabdomys pumilio. In two-way choice tests, we presented females with olfactory cues from males differing in levels of paternal care quality, paternal care experience, or mating experience. We predicted that females would prefer: (i) males showing higher levels of care; (ii) paternally experienced over paternally naïve males; and (iii) sexually experienced over sexually naïve males. Females did not distinguish between males of differing paternal care quality or paternal care experience, but maternally experienced females showed a preference for sexually experienced over sexually naïve males. Females may prefer sexually experienced males because these males are able to defend territories for breeding. We conclude that paternal care is selectively advantageous because of its apparent fitness benefits. Nonetheless, our study shows that paternal care has evolved independently of female choice in striped mice, since females did not choose between males of differing paternal care abilities.

Stereotypic behaviour is genetically transmitted in the African striped mouse Rhabdomys pumilio

The development of stereotypic behaviour was studied in captive striped mice, Rhabdomys pumilio. Based on the findings of previous studies, it was hypothesised that there is a genetic basis for stereotypy in striped mice. Breeding and cross-fostering experiments were used to test this hypothesis. Two treatments were performed per experiment, involving pairings of: (i) stereotypic females and non-stereotypic males; and (ii) non-stereotypic females and non-stereotypic males. In breeding experiments, the incidences of stereotypy were approximately four times more common in the offspring of stereotypic females than in those of non-stereotypic females. Cross-fostering of young between treatments (stereotypic and non-stereotypic females) or within treatments (control experiments) did not influence the patterns of transmission of stereotypy. The data indicate that the development of stereotypy in captive R. pumilio is strongly related to its occurrence in the biological mother. However, there was no congruence between the type of stereotypies displayed by mothers and offspring, with almost all stereotypic offspring displaying one type of stereotypy (cage-lid climbing and back-flipping). The results show that there is a strong genetic basis for the development of stereotypy in striped mice, while social influences appear to be minimal.

Fostering in the African striped mouse: implications for kin recognition and dominance

Fostering was studied in the African striped mouse Rhabdomys pumilio (Sparrman, 1784) in captivity to establish if females can distinguish their own from strange pups, and if fostering affected the biology of fostered pups.

The effects of sibling reproduction in the African striped mouse

Sibling reproduction was studied in a captive population of the African striped mouse Rhabdomys pumilio (Sparrman, 1784) to establish the occurrence of inbreeding and whether early association prevents later matings.