Male care for offspring is unexpected in polygynandrous mammals. Evidence from nonhuman primates, however, indicates not only the existence of stable male–immature associations in multimale–multifemale groups, but also male care in the form of protection from infanticidal attacks and conspecific harassment. Here, we investigate the relationship characteristics, dynamics, and consequences of male–immature associations in wild Assamese macaques, Macaca assamensis, at Phu Khieo Wildlife Sanctuary, Thailand, to inform hypotheses of their evolutionary origins. Female Assamese macaques reproduce seasonally and do not signal ovulation, resulting in low mating and paternity skew. However, male–immature associations are predicted by paternity, and male behavior potentially reflects paternal effort. We present focal animal data on 12 immatures followed from birth beyond weaning into their juvenile life (1188 focal hours). The distribution of composite sociality indices suggests that male–immature relationships were highly differentiated. Association patterns and the degree of differentiation remained stable from 6 mo well into the juvenile phase, suggesting that male protection extends beyond the phase of high infanticide risk. Based on Hinde indices, immatures were responsible for maintaining the relationships. The likelihood that an infant was associated with its preferred male increased if the mother was absent and if other males were present in proximity, suggesting that immatures sought protection. The presence of the preferred male did not decrease the rate of mild aggression immatures received from group members, but the stronger the relationship between an immature and a male, the more often it received agonistic support from him. Future studies will have to assess whether this agonistic support translates into improved fitness and represents true paternal care.

The transcription factor FOXP2 has been linked to severe speech and language impairments in humans. An analysis of the evolution of the FOXP2 gene has identified two amino acid substitutions that became fixed after the split of the human and chimpanzee lineages. Studying the functional consequences of these two substitutions in the endogenous Foxp2 gene of mice showed alterations in dopamine levels, striatal synaptic plasticity, neuronal morphology and cortico-striatal-dependent learning. In addition, ultrasonic vocalizations (USVs) of pups had a significantly lower average pitch than control littermates. To which degree adult USVs would be affected in mice carrying the 'humanized' Foxp2 variant remained unclear. In this study, we analyzed USVs of 68 adult male mice uttered during repeated courtship encounters with different females. Mice carrying the Foxp2 hum/hum allele did not differ significantly in the number of call elements, their element structure or in their element composition from control littermates. We conclude that neither the structure nor the usage of USVs in adult mice is affected by the two amino acid substitutions that occurred in FOXP2 during human evolution. The reported effect for pup vocalization thus appears to be transient. These results are in line with accumulating evidence that mouse USVs are hardly influenced by vocal learning. Hence, the function and evolution of genes that are necessary, but not sufficient for vocal learning in humans, must be either studied at a different phenotypic level in mice or in other organisms.

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We used radiocollars and GPS collars to determine the movements and habitat selection of golden jackals (Canis aureus) in a seasonally dry deciduous forest with no human settlements in eastern Cambodia. We also collected and analyzed 147 scats from jackals to determine their seasonal diet and prey selection. The mean (± SE) annual size of home-range ranges (47.1 ± 2.5 km2; n = 4), which were mutually exclusive between mated pairs, was considerably larger than that previously reported for this species, resulting in an extremely low density (0.01 jackal/km2). The unusually large home ranges and low density probably were due to the harsh dry season when most understory vegetation is burned and nearly all waterholes dry up, thereby causing a large seasonal decline in the availability of small vertebrate prey. Resident groups consisted of an alpha pair, but no betas, and were situated only in areas not occupied by leopards (Panthera pardus) and dholes (Cuon alpinus). Jackals avoided dense forests and streams, and had a strong selection for dirt roads, possibly to avoid larger predators. Overall the jackal diet was diverse, with at least 16 prey items identified, and there was no significant difference in diet composition between the cool-dry and hot-dry seasons. Scat analysis showed that the main food items consumed by jackals were processional termites (Hospitalitermes spp.; 26% biomass consumed), followed by wild pig (Sus scrofa; 20%), muntjac (Muntiacus vaginalis; 20%), and civets (17%). Compared to available biomass, jackals were not random in their consumption of ungulates because muntjac were selectively consumed over larger ungulate species. Dietary overlap with dholes and leopards was relatively low, and consumption patterns indicated jackals were preying on ungulates rather than scavenging from kills of larger carnivores. Our results showed that the jackal is an extremely adaptable and opportunistic species that exhibits unique behaviors to survive in an extreme environment near the edge of its distribution.

Animals’ space requirements may vary according to life-history and social considerations. We observed 516 wild adult Asian elephants from both sexes, over 9 years, to investigate how life-history traits and social behavior influence protected-area (PA) use at Udawalawe National Park, Sri Lanka. Male PA-use, quantified in terms of average between-sightings-interval (BSI), was significantly influenced by the interaction of age class and motivational state (i.e. reproduction vs. foraging). Musth lengthened with age, with a median of 24.5 days for ages 21–30, 32.5 days for ages 31–40, and 45 days for those > 40. A minority (11%) used it exclusively during musth, while others used it exclusively for foraging (44%) or both (45%). Males using it in both states and older musth-only males were more likely to be seen across years. There were 16 social communities containing between 2–22 adult females. Females’ BSI was significantly influenced by social ties, but this relationship was weak, because members of social communities do not necessarily disperse together, resulting in high individual variation in space-use. Inter-annual variability in sightings among individuals of both sexes indicates that around ¾ of the population is likely non-residential across years, challenging the prevailing fortress-conservation paradigm of wildlife management.