bioRxiv Science⌕ Search

bioRxiv · 10.1101/485144

Effects of male age and female presence on male associations in a large, polygynous mammal in southern India

Abstract

We present a detailed study of male associations in a roving species, the Asian elephant, using six years of data on identified, nonmusth males. Adult males spent greater proportions of their time solitarily than in mixed-sex or in all-male groups. Old (over 30 years) males were sighted more frequently with their age-peers and less frequently with young (15-30 years) males than expected at random in all-male groups. Young males were not sighted more frequently with old males than with young males, and did not disproportionately initiate associations with old males. These results suggest that male associations, in the absence of females, primarily allow for old nonmusth males to test strengths against age-peers. Social learning from older individuals did not seem to be important in male associations, unlike that observed in African savannah elephants. We also found a constraint on the sizes of all-male groups, similar to that seen in female groups in our study population, and with male group sizes being smaller than that of African savannah elephants. However, most males had a significant top associate in female absence. In mixed-sex groups, male associations occurred at random, suggesting that males were tracking female groups independently. Thus, we find some differences in male social organisation compared to the phylogenetically related African savannah elephant that occupies a similar niche, and suggest that ecological factors might have shaped the differences in these male societies.Competing Interest StatementThe authors have declared no competing interest.View Full Text

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Keerthipriya, P., Nandini, S., Vidya, T. N. C.. 2018-12-04. Effects of male age and female presence on male associations in a large, polygynous mammal in southern India. https://doi.org/10.1101/485144

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

A hawkmoth's point of view - Innate symmetry preferences are informed by floral display and foraging function in an insect pollinator

Floral visual cues are key for flower recognition and feeding in many pollinators. In insects, innate preferences for characteristic floral colour and pattern cues can guide naive foragers during their initial foraging. Symmetry is suggested to be one such foraging cue, since it is a remarkably conserved floral feature, with flowers mainly displaying radial or bilateral morphologies. Insect pollinators like honeybees, bumblebees, and hoverflies have been found to distinguish symmetry from asymmetry spontaneously or through learning. However, whether innate preferences for floral symmetry types, i.e. radial or bilateral, influence naive flower choice, and whether such preferences are linked to functional benefits during foraging remains uncertain.We investigated innate symmetry choice and its associated foraging function in the hummingbird hawkmoth (Macroglossum stellatarum). Besides relying on pattern cues for flower choice, these hawkmoths feed while hovering, making symmetry a valuable visual cue for flight and proboscis control. In choice assays, the hawkmoths' innate preferences for symmetry types depended on the floral display planes, with considerable differences between the horizontal and vertical displays. Tracking the hawkmoths during foraging revealed that in both display planes, the innately preferred patterns increased foraging success by guiding approach and nectary search. While an analysis of flowers visited by hawkmoths in nature did not reveal the same link between symmetry and display plane, a majority of plant species with vertically displayed flowers showed features matching those innately preferred by the hawkmoths. In this study, we provide the first instance of display-dependent innate foraging preferences and highlight how visuomotor strategies in nectivorous insects may have coevolved with flower features.

animal behavior and cognition↗

Calves function as social magnets in a species with high fission-fusion dynamics, the Asian elephant

Individuals living in fission-fusion societies may face unique challenges in maintaining social relationships, as the repeated fission of social units can limit opportunities for social interaction. However, the presence of young offspring may often necessitate cooperation among individuals. To understand whether offspring promote sociality in fission-fusion species, we studied wild Asian elephants (Elephas maximus) in southern India. Using nearly 5900 female group sightings collected over 9 years, we tested whether calf presence predicted female group size and associations. The numbers of adult, young adult, and subadult females in groups were 2-2.5-fold higher in calf presence than absence, which may facilitate collective defence of calves. Furthermore, the number of females without their own dependent offspring, who often provide allomaternal care, was also higher in calf presence than absence. Social network analysis revealed that adult females formed more numerous and stronger associations in calf presence than absence, which may facilitate consistent allomaternal care. Our results thus suggest that the need to protect calves and to provide allomaternal care likely promote sociality among female elephants. We propose that dependent offspring may function as social ties in fission-fusion species, contingent upon the prevailing conditions and the socioecological pressures that have shaped their social systems.

animal behavior and cognition↗

Mating behaviour, mate choice, and reproduction in Tyrophagus curvipenis (Acari: Acaridae)

Mating behaviour and mate choice can influence reproductive output, but these aspects remain insufficiently studied in many mite species. This study investigated mating behaviour, mate choice, and the reproductive consequences of repeated mating in Tyrophagus curvipenis (Acari: Acaridae). First, we described the mating sequence and quantified the duration of pre-copulation latency and copulation duration. Mating involved initial contact, dorsal mounting, repositioning into a tail-to-tail copulatory position, and sperm transfer. Copulation lasted substantially longer than the pre-copulation latency. Second, we examined mate choice in relation to kinship. Neither males nor females showed a significant preference for siblings or unrelated partners. Third, we examined mate choice in relation to mating status. Males preferred virgin partners, whereas females showed no significant preference between virgin and previously mated partners. Copulation duration was shorter with previously mated partners, although the underlying cause remains unclear. Finally, we examined female reproductive performance under three mating-frequency treatments: one mate, two mates, and unlimited access to mates. Mating frequency did not affect the pre-oviposition period but significantly affected the oviposition period, daily oviposition rate, and total fecundity. Females with unlimited mating opportunities had the longest oviposition period and produced the most eggs. Among females that mated once, longer copulation was positively associated with both oviposition period and total fecundity. These findings characterise mating behaviour in T. curvipenis and show that mate choice and mating frequency are associated with different aspects of reproduction. Further work is needed to determine whether these patterns reflect differences in sperm transfer, fertilisation, or other effects of mating.

animal behavior and cognition↗