Ambient temperature as a determinant of landscape use in the savanna elephant, Loxodonta africana

Elephants occur in landscapes where temperatures can reach 50 °C. Due to their large size they may face physiological problems of dissipating heat during such high temperatures. In spite of this, no one seems to have considered ambient temperature as limiting landscape choices in elephants. We recorded hourly landscape use in free-ranging elephants using GPS collars. We also placed temperature data loggers in each of the landscapes, to obtain corresponding ambient temperatures for each hour. Our results suggest that elephants may select landscapes based on the rate at which temperatures changed and also for shade. We suggest that these selected variables provide a thermal benefit to individuals. As such, we propose that landscape use in elephants may be constrained by their thermal physiological requirements as well as other resources such as food and water.We would like to thank the International Fund for Animal Welfare for financing this project and the Zambian Wildlife Authority for allowing this study to occur. We would particularly like to thank the Ngoma and Lower Zambezi Area Management Units, Conservation Lower Zambezi, J. Hanks, J. Fourie, T. Simpamba, B. Kabungo, N. Fairall, S. Ferreira and R. Guldemond for their assistance and support. AK received a post-doctoral fellowship from the University of Pretoria. This study complied with the current laws in Zambia and was sanctioned by the ethics committee of the University of Pretoria (clearance code: AUCC 040611-013). The comments from two anonymous referees contributed to improving the manuscript

Sexual selection and genital allometry in the Hottentot golden mole (Amblysomus hottentotus)

Under sexual selection, genitalia typically undergo rapid and divergent evolution across species and competition between the sexes over control of fertilisation may drive the co-evolution of male and female sexual traits. Sexual selection can, therefore, influence genitalia in three fundamental but non-mutually exclusive ways: (1) cryptic female choice, (2) sperm competition and (3) sexual conflict. Golden moles (Chrysochloridae) are a highly specialised family endemic to sub-Saharan Africa. We examined intraspecific genital allometry of both male and female subterranean Hottentot golden moles (Amblysomus hottentotus). Consistent with previous studies in mammals, we found positive allometry and a high coeffi- cient of variation (CV) for male genitalia. The results for female reproductive tract length of A. hottentotus contrast with the findings of previous studies as isometry was recorded. Based on the allometric relationships of both males and females presented here, we suggest that the males do not sequester females and that in the absence of visual cues the female may use penis size as an indicator of phenotypic quality.An honours bursary was awarded to T.A.R from the South African Research Chair Initiative of Mammal Behavioural Ecology and Physiology by the NRF/DST to N.C.B. The research was supported by a National Research Foundation Grant to N.C.B.http://www.elsevier.com/locate /mambiohb2016Mammal Research InstituteZoology and Entomolog

Effects of anthropogenic disturbance on bird diversity in Ethiopian montane forests

The Afromontane forests of Ethiopia are global biodiversity hotspots, known for their high biological diversity and endemism. However, conservation of these areas is challenging due to increasing human threats, including encroachment of agriculture and settlements, overgrazing of livestock, and selective logging. We examined the effects of forest disturbances on birds, and highlights the potential conservation value of unprotected tropical montane forests for birds in the dry evergreen Afromontane forests of the Bale Mountains, Ethiopia. We sampled birds across 2 yr in both protected forests (characterized by low levels of cultivation, overgrazing, and logging) and unprotected forests (higher levels of disturbance). Using functional traits of birds related to habitat type, diet, and foraging stratum, we characterized the differences between protected and unprotected forests in terms of avian species richness, abundance, and assemblage composition. Overall, species richness was 27% higher and bird abundance was 19% higher in unprotected forests. In contrast, species richness and abundance of forest specialists and canopy foragers were significantly higher in protected forests. These findings suggest that unprotected, disturbed tropical montane forests in Ethiopia help to achieve conservation aims in an area recognized for its global biodiversity importance. At the same time, intact forest ecosystems need continued protection to maximize functional heterogeneity associated with specialist tropical forest taxa

Do mating strategies determine genital allometry in African mole rats (Bathyergidae)?

Allometry describes the relationship of components of an organism with change in overall body size and has become the focus of numerous studies on the evolution of genitalia. Typically, negative allometry is observed in insects and is explained by stabilizing selection whereas the very few studies on mammals have shown a positive allometric relationship of genitalia in the body size, thought to have arisen as a result of sexual selection. However, all mammal species studied to date are thought to use mainly post-copulatory mating strategies. Across mammals, however, both pre-and post-copulatory strategies occur (although the two are not mutually exclusive). We propose that where pre-copulatory strategies are mainly used, no reproductive benefits would result from evolving positively allometric genitalia. As such, mammal genitalia are not typically positively allometric but rather allometry will, to a certain degree, be determined by mating strategy. We tested this prediction using four species of African mole rats (Bathyergidae) exhibiting variation in their life histories and mating strategies. Although generally supported, in that positive allometry did not occur in species that we assumed use mainly pre-mating strategies, positive allometry did not occur in either of the promiscuous species thought to use post-copulatory strategies. We suggest, therefore, that while mating strategies may tentatively determine genital allometry, whether positively allometric genitalia occur also depends on a number of complex interacting factors. In addition, this study provides further evidence and empirical support for the co-evolution of male and female genitalia in mammals

Structure and allometry of genitalia in males and females of a social African ground squirrel with high polygynandry

The few studies that have looked at genital allometry in mammals have typically shown a positively allometric relationship with body size and high coefficients of variation. Cryptic female choice, sexual conflict or sperm competition are mechanisms underlying genital evolution and as these are not mutually exclusive, they are often difficult to disentangle. In addition, these mechanisms are affected by both male and female social structure and/or mating strategies and, as such, pre- and post-copulatory behaviours have been shown to alter selection on genitalia. We examined genital traits and allometry in a polygynandrous and social ground squirrel Xerus inauris. We found that male testes are positively allometric and account for 1.5% of their body weight, one of the highest percentages known for sciurids. The penis, at 42.4% of head/body length, was isometric while the female reproductive tract, 22.4% head/body length, demonstrated no such relationship. Based on the allometric relationships of both males and females presented here, in conjunction with high levels of competition for females and lack of male aggression and territoriality, we suggest that sperm competition is the most likely mechanism for the evolution of the extremely large genitalia in this species

Body temperature daily rhythm adaptations in African savanna elephants (Loxodonta africana)

Please refer to abstract of articl