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Incorporating mate choice into conservation breeding programs can improve reproduction and the retention of natural behaviors. However, different types of genetic‐based mate choice can have varied consequences for genetic diversity management. As a result, it is important to examine mechanisms of mate choice in captivity to assess its costs and benefits. Most research in this area has focused on experimental pairing trials; however, this resource‐intensive approach is not always feasible in captive settings and can interfere with other management constraints. We used generalized linear mixed models and permutation approaches to investigate overall breeding success in group‐housed Tasmanian devils at three nonmutually exclusive mate choice hypotheses: (a) advantage of heterozygous individuals, (b) advantage of dissimilar mates, and (c) optimum genetic distance, using both 1,948 genome‐wide SNPs and 12 MHC‐linked microsatellites. The managed devil insurance population is the largest such breeding program in Australia and is known to have high variance in reproductive success. We found that nongenetic factors such as age were the best predictors of breeding success in a competitive breeding scenario, with younger females and older males being more successful. We found no evidence of mate choice under the hypotheses tested. Mate choice varies among species and across environments, so we advocate for more studies in realistic captive management contexts as experimental or wild studies may not apply. Conservation managers must weigh up the need to wait for adequate sample sizes to detect mate choice with the risk that genetic changes may occur during this time in captivity. Our study shows that examining and integrating mate choice into the captive management of species housed in realistic, semi‐natural group‐based contexts may be more difficult than previously considered. [ABSTRACT FROM AUTHOR]

My research on anurans has been diverse: biogeography, speciation, acoustics, polyandry, sperm competition, and conservation. My interests in biology started in natural history but, in the late 1960s as an undergraduate student, I was receptive to emerging new ideas in biogeography and evolutionary biology: continental drift and neutral theory. My focus in this "Perspective" is an explanation of how diversity has evolved in the frog fauna of southwestern Australia, where I have worked since 1978. I discuss the roles of range fragmentation, genetic drift, directional sexual selection, polyploidy, and simultaneous polyandry as processes driving the evolution of diversity in the sometimes-bizarre frog fauna of southwestern Australia. I identify features that can characterize polyandrous anurans: e.g., large testes, sperm morphology, and, possibly, complex calls with an example of the latter in Geocrinia leai. I discuss how current anuran life histories vary across rainfall and temperature gradients and how derivation of more-arid adapted forms is a well-defined historic biogeographic pattern in southwestern Australia. My observations over time leave me cautiously optimistic about the prospects for frogs affected by global warming. [ABSTRACT FROM AUTHOR]

Echidnas are egg‐laying mammals found across Australia, and in Tasmania they hibernate, resulting in a most unusual mating system: males enter hibernation in late summer–early autumn and arouse in late autumn–early winter to mate, although females are still hibernating. Groups of males compete for matings and both males and females mate with multiple partners. Females that mate early return to hibernation even when pregnant, and males continue to mate with pregnant females. We asked to what extent can the bizarre combination of behavioural and physiological features that characterize reproduction of Tasmanian echidnas be attributed to their phylogeny, and how much is a consequence of their ecology?To understand the interaction between energetics and the echidna mating system in determining the timing of echidna hibernation, we analysed data from an 18‐year study of a wild population of Tasmanian echidnas (Tachyglossus aculeatus setosus)Males in best condition arouse earliest and seek out suitable females, and females that mate early in the mating season re‐enter hibernation while pregnant.Competition between males drives early mating and while mating with males in the best condition could be advantageous for females and their young, egg‐laying in winter is potentially disadvantageous, and post‐mating hibernation by females is a means of delaying hatching of young until environmental conditions are more favourable. This post‐mating hibernation by females is usually disrupted by males which mate with them although they are already pregnant.Comparisons with other echidna populations suggest that a decreased activity period due to hibernation has not increased male–male competition.Similar competition between groups of males for access to females is seen in chlamyphorid armadillos, which occupy a similar ecological niche to echidnas. A free Plain Language Summary can be found within the Supporting Information of this article. [ABSTRACT FROM AUTHOR]

Multiple mating is a common reproductive strategy among mammals, and rodents living in communal, mixed sex social groups are predisposed to a polygamous existence. The sandy inland mouse is a naturally polyandrous species that occurs across most of Australia's arid region. Females typically have greater reproductive restrictions compared with males and are therefore expected to acquire substantial fitness benefits from copulating with more than one male. Here, I show that the reproductive output of female sandy inland mice did not differ between females mated monandrously (single male) or polyandrously (two males). Paternity data obtained from the polyandrous litters revealed that in most cases, there was a first male-to-mate advantage. I discuss this result in relation to the chastity enforcement hypothesis for the evolution of the copulatory plug. Finally, I compared ejaculate traits of competing males and found that the paternity loss of males that mated first was attributable to their own sperm density and sperm quality, and not to that of their rivals. The sperm data also revealed that second males gained greater paternity representation when sperm velocities and motilities were higher in first-mated males. This investigation indicates that mating position is a critical determinant of male fitness in mammalian sperm competition. [ABSTRACT FROM AUTHOR]

Male-male competition after mating (sperm competition) favours adaptations in male traits, such as elevated sperm numbers facilitated by larger testes. Ultimately, patterns of female distribution will affect the strength of sperm competition by dictating the extent to which males are able to prevent female remating. Despite this, our understanding of how the spatial and temporal distributions of mating opportunities have shaped the evolutionary course of sperm competition is limited. Here, we use phylogenetic comparative methods to explore interspecific variation in testes size in relation to patterns of female distribution in Australian rodents. We find that as mating season length (temporal distribution of females) increases, testes size decreases, which is consistent with the idea that it is difficult for males to prevent females from remating when overlap among oestrous females is temporally concentrated. Additionally, we find that social species (spatially clustered) have smaller testes than non-social species (spatially dispersed). This result suggests that males may be effective in monopolizing reproduction within social groups, which leads to reduced levels of sperm competition relative to non-social species where free-ranging females cannot be controlled. Overall, our results show that patterns of female distribution, in both space and time, can influence the strength of post-mating sexual selection among species.