• Body size and sexual selection in the koala

      Ellis, William A.; Bercovitch, Fred B. (2011)
      ...Koalas are sexually dimorphic in multiple domains, yet are absent from the literature on sexual selection and the structure of their mating system is unclear. We provide the first documentation of the strength of sexual selection in koalas by using microsatellite markers to identify sires....
    • Conspecific attraction

      Swaisgood, Ronald R.; Mills, D.S.; Marchant-Forde, J.N.; McGreevy, P.D.; Morton, D.B.; Nicol, C.J.; Phillips, C.J.C.; Sandoe, P.; Swaisgood, Ronald R. (CABICambridge, MA, 2010)
    • Cross-cultural consensus for waist–hip ratio and women's attractiveness

      Singh, Devendra; Dixson, B. J.; Jessop, T. S.; Morgan, Bethan J.; Dixson, Alan F.; (2010)
      In women of reproductive age, a gynoid body fat distribution as measured by the size of waist–hip ratio (WHR) is a reliable indicator of their sex hormone profile, greater success in pregnancy and less risk for major diseases. According to evolutionary mate selection theory, such indicators of health and fertility should be judged as attractive….
    • Demographic, environmental and genetic determinants of mating success in captive koalas (Phascolarctos cinereus)

      Abts, Kendra C.; Ivy, Jamie A.; DeWoody, J. Andrew (2018)
      Many factors have been shown to affect mating behavior. For instance, genes of the major histocompatibility complex (MHC) are known to influence mate choice in a wide variety of vertebrate species....
    • Effects of season and social interaction on fecal testosterone metabolites in wild male giant pandas: implications for energetics and mating strategies

      Nie, Yong-Gang; Zhang, Ze-Jun; Swaisgood, Ronald R.; Wei, Fu-Wei (2012)
      In the first-ever study of reproductive endocrinology in wild male giant pandas (Ailuropoda melanoleuca), we provide new insights into the reproductive ecology of the species. We tracked and observed pandas in Foping Nature Reserve of the Qinling Mountains for 3 years, collecting fecal samples for testosterone metabolite analysis and data on reproductive activity....
    • Impacts of natural history and exhibit factors on carnivore welfare

      Miller, Lance J.; Ivy, Jamie A.; Vicino, Greg A.; Schork, Ivana G. (2019)
      To improve the welfare of nonhuman animals under professional care, zoological institutions are continuously utilizing new methods to identify factors that lead to optimal welfare. Comparative methods have historically been used in the field of evolutionary biology but are increasingly being applied in the field of animal welfare....
    • Koala bellows and their association with the spatial dynamics of free-ranging koalas

      Ellis, William A.; Bercovitch, Fred B.; FitzGibbon, S.; Roe, P.; Wimmer, J.; Melzer, A.; Wilson, R. (2011)
      Acoustic communication mediates sociality in a variety of animals. One of the more ubiquitous vocal signals to have evolved is the sexual advertisement call of males. Koala (Phascolarctos cinereus) males emit a sonorous bellow call during the breeding season, but no detailed studies of the calling context appear to have been published. We used a novel remote sound detection network to monitor koala bellowing while simultaneously collecting koala behavioral data using collar-mounted GPS units. Our approach enabled us to examine fine scale temporal variation in vocalization and spatial movements of free-ranging koalas without direct behavioral observations. Bellow occurrence was susceptible to weather conditions, with fewer calls occurring when wind speed and temperatures were high. The number of bellow vocalizations recorded during an annual period mirrored breeding activity, with nearly all male bellows recorded during peak mating season. The distance traveled by koalas and the occurrence of koala bellows both peaked around midnight, but only female travel distance during the breeding season was temporally correlated with bellow occurrence. We conclude that environmental factors might trigger male bellowing to launch the breeding season and that these male vocal signals function more to attract females than to repel males. Female mate selection is probably an important component of male reproductive success in koalas, which is partly mediated by male bellow characteristics.
    • Mating strategies

      Steyaert, Sam M.J.G.; Zedrosser, Andreas; Swaisgood, Ronald R.; Filipczykova, Eva; Crudge, Brian; Dutta, Trishna; Sharma, Sandeep; Ratnayeke, Shyamala; Koike, Shinsuke; Leclerc, Martin; et al. (Cambridge University PressCambridge, 2020)
      The mating system and mating strategies of a species refer to the behavioral strategies used to obtain reproductive partners and ensure reproductive success. Common determining factors of mating systems and strategies are: the manner of mate acquisition, the number of mates obtained by an individual, as well as the absence or presence and duration of parental care….
    • Reproductive competition and fecal testosterone in wild male giant pandas (Ailuropoda melanoleuca)

      Nie, Yonggang; Swaisgood, Ronald R.; Zhang, Zejun; Liu, Xiaobin; Wei, Fuwen (2012)
      ...Using global positioning system/very high frequency radiocollars to locate mating aggregations, we used behavioral observations and fecal testosterone assays to gain insight into male panda reproductive effort and strategies, and test theories relating to reproductive competition. Male pandas initially competed fiercely for access to females that were about to be fertile, but once male competitive status was determined, aggression rates declined....
    • Sociality and signaling activity modulate information flow in river otter communication networks

      Barocas, Adi; Golden, Howard N; Dudenhoeffer, Megan; Ben-David, Merav (2020)
      …In concert, our results suggest that in river otters, scent-marking decisions minimize signal dilution by being performed in small groups and maximize the receivers through preferential signaling at latrines with higher, more recent activity. Because signaling decisions in social animals are linked to key life-history events such as mating and group membership shifts, understanding their individual and population-level drivers can be crucial.