Environmental change poses challenges to many organisms. The resilience of a species to such change depends on its ability to respond adaptively. Social flexibility is such an adaptive response, whereby individuals of both sexes change their reproductive tactics facultatively in response to fluctuating environmental conditions, leading to changes in the social system. Social flexibility focuses on individual flexibility, and provides a unique opportunity to study both the ultimate and proximate causes of sociality by comparing between solitary and group‐living individuals of the same population: why do animals form groups and how is group‐living regulated by the environment and the neuro‐endocrine system? These key questions have been studied for the past ten years in the striped mouseRhabdomys pumilio. High population density favours philopatry and group‐living, while reproductive competition favours dispersal and solitary‐living. Studies of genetic parentage reveal that relative fitness of alternative reproductive tactics depends on the prevailing environment. Tactics have different fitness under constrained ecological conditions, when competitive ability is important. Under conditions with relaxed ecological constraints, alternative tactics can yield equal fitness. Both male and female striped mice display alternative reproductive tactics based on a single strategy, i.e. all individuals follow the same decision rules. These changes are regulated by endocrine mechanisms. Social flexibility is regarded as an adaptation to unpredictably changing environments, selecting for high phenotypic flexibility based on a broad reaction norm, not on genetic polymorphism for specific tactics.

Human–wildlife conflict (HWC), due to competition for shared natural resources between people and wildlife, influences food security of people and the well-being of people and animals. HWC is a major concern in developing countries, affecting people of different socio-economic classes. We conducted a meta-analysis of the occurrence of published scientific reports on HWC globally and South Africa particularly, to identify vulnerable human communities and their farming practices in developing and developed countries, and vulnerable wildlife guilds. We accessed Institute for Scientific Information publications from 1994 to 2015. Local communities (people living contiguous with protected natural areas) and commercial farmers jointly experienced the highest HWC incidences compared to subsistence farmers, possibly due to reporting bias for commercial farmers. Rural people in Africa and Asia experienced conflict with a diversity of mammals, confirming our expectation that developing countries could potentially experience regular encounters with wildlife. South Africa had more HWC cases than developed countries (e.g., in Australia and North America), yet the dichotomy between first world and third world economies in South Africa provides a regional exemplar of global patterns in HWC. Globally, HWC involved mainly mammals and birds, with carnivores and primates as the most high-scale conflict species and thus were a severely persecuted group. Our foundational research provides the first global assessment of HWC and showed that people in developing countries are vulnerable to HWC, perhaps related to reduced protection of livestock and crops against a larger guild of problem mammals. We suggest that a wider range of literature, including governmental and non-governmental publications, be surveyed to contribute to further research in this area of study.

Animals may respond to seasonally changing environments with physiological and behavioral strategies. Whereas migration is a behavioral strategy used by many taxa, it may not be an option for small mammals. However, small mammals can seasonally vary the area of habitat in which they are active. The striped mouse Rhabdomys pumilio in the semiarid Succulent Karoo of South Africa lives in a seasonal environment, characterized by hot, dry summers with low food abundance and cold, wet winters, followed by high food abundance in spring. We radio tracked a total of 28 females during the 2004 dry season, the following breeding season in spring, and the following dry season in 2005 and tested the prediction that females shift their home ranges in relation to food availability. Females shifted their home ranges from an area characterized by evergreen succulent shrubs in the vicinity of a dry riverbed in the dry season to sandy areas that were characterized by new plant growth of annuals in spring. Home ranges during the breeding season in spring had a higher percentage of annuals than dry season home ranges measured in spring. Female home range size increased during the breeding season. We suggest that female striped mice shift their home ranges seasonally to gain access to protein-rich young plant material, which is important for breeding.

The relative plasticity hypothesis predicts that alternative tactics are associated with changes in steroid hormone levels. In species with alternative male reproductive tactics, the highest androgen levels have usually been reported in dominant males. However, in sociable species, dominant males show amicable behaviors to gain access to females, which might conflict with high testosterone levels. We compared testosterone, corticosterone, and resting metabolic rate in male striped mice (Rhabdomys pumilio) following a conditional strategy with three different reproductive tactics: (i) philopatric group-living males, (ii) solitary-living roamers, (iii) dominant but sociable group-living territorial breeders. Philopatrics had the lowest testosterone but highest corticosterone levels, suggesting that they make the best of a bad job. Dominant territorial breeders had lower testosterone levels than roamers, which have a lower competitive status. Roamers had the highest testosterone levels, which might promote risky behavior, such as invading territories defended by territorial males. Roamers also had lower resting metabolic rates than either type of group-living males. Our results suggest that dominant males' testosterone levels reflect a trade-off between low testosterone amicable behavior and high testosterone dominance behavior.