Sequential Polygyny During Egg Attendance is Rare in a Tree Frog and Does not Increase Male Fitness

Abstract

Sequential polygyny is a reproductive strategy that allows males to continue to mate and compensates for the loss of future breeding opportunities incurred by parental care (i.e. egg attendance). Using the frog Kurixalus eiffengeri, we tested predictions that (1) attending males fathered two, overlapping clutches; and (2) that double clutching leads to improved offspring numbers. Using five microsatellite DNA markers, we genotyped 15 pairs of overlapping clutches, which differed slightly in developmental stage at a single egg‐laying site. Parentage analyses showed at least 12 of 15 pairs of overlapping egg clutches were sired by the attending male mated with different females, providing the first genetic evidence to support an earlier prediction that attending males sired both egg clutches. Field surveys found a low incidence of overlapping clutches (4.9% of 263 egg‐occupied stumps), suggesting sequential polygyny is uncommon. Stumps with multiple clutches contained significantly more eggs than stumps with single clutches but hatched similar number of tadpoles. Results suggest that continuous calling that attracts females during egg attendance is a reproductive tactic that maximizes mating opportunities. However, adoption of the sequential polygyny tactic may only result in marginal fitness gains for males that are traded off against average higher egg mortality in larger egg clutches.

The Adaptive Significance of Egg Attendance in a South‐East Asian Tree Frog

“…To further complicate matters, even in cases where adults can care for multiple clutches, it is not necessarily correlated with increase in adult fitness (Cheng et al. ), on top of which individuals could be providing care to unrelated embryos (Chen et al. ).…”

“…Of course, costs of egg attendance can vary greatly for either parent, both between and within species, depending on time and energy invested. To further complicate matters, even in cases where adults can care for multiple clutches, it is not necessarily correlated with increase in adult fitness (Cheng et al 2013), on top of which individuals could be providing care to unrelated embryos (Chen et al 2011). It is clear, however, in the case of C. hansenae that benefits of egg attendance exceed costs, as clutches are unable to develop without attending females.…”

Developments in Amphibian Parental Care Research: History, Present Advances, and Future Perspectives

“…Other studies have demonstrated other complex ways that parental care can benefit offspring: larger size of brooding males in A. obstetricans and Alytes cisternasii (Raxworthy 1990;Márquez 1993), sequential vs. nonsequential clutch attendance in K. eiffingeri (Cheng et al 2012), and differences expressed among allopatric color morphs in O. pumilio (Dugas and Richards-Zawacki 2015). Such findings suggest that we are only beginning to understand the complex interactions between parental care and offspring fitness in anurans.…”

The unexpected genetic mating system of the red‐backed toadlet (Pseudophryne coriacea): A species with prolonged terrestrial breeding and cryptic reproductive behaviour

“…To date, genetic analyses of mating systems have been made for <20 species, representing <1% of all described species. Nevertheless, considerable diversity has already been uncovered, with reports of mating systems ranging from extreme monogamy and polygyny, to extreme polyandry and polygynandry (Brown, Morales, & Summers, 2010;Byrne & Keogh, 2009;Cheng, Chen, Yu, Roberts, & Kam, 2013;Knopp & Meril€ a, 2009;Laurila & Sepp€ a, 1998;Lod e & Lesbarr eres, 2004;Ringler, Ringler, Jehle, & H€ odl, 2012;Wang, Xie, Wang, & Jiang, 2014). Critically, however, the vast majority of these studies have only considered a fraction of a species' breeding season or sampled a very small subset of breeding individuals and offspring.…”