Factors influencing tadpole deposition site choice in a frog with male parental care: An experimental field study (original) (raw)
Related papers
2006
Temporal variability of spawning site selection in the frog Rana dalmatina: consequences for habitat management.-We evaluated whether R. dalmatina females laid their eggs randomly within a pond or preferred particular microhabitats. The same measures were performed in the same area in two consecutive years to determine whether the pattern remained constant over time. In 2003, we observed a significant selection for areas with more submerged deadwood and vegetation, presence of emergent ground and low water depth. However, these results were not confirmed in the subsequent year when none of the microhabitat features measured had a significant effect. Although microhabitat features can strongly influence tadpoles, the temporal variability of habitat at this spatial scale suggests that habitat management could be more effective if focused on a a wider spatial scale.
Frontiers in Zoology, 2013
Introduction: Individuals should aim to adjust their parental behaviours in order to maximize the success of their offspring but minimize associated costs. Plasticity in parental care is well documented from various bird, mammal and fish species, whereas amphibians were traditionally assumed as being highly instinct-bound. Therefore, little is known about 'higher' cognitive abilities of amphibians, such as strategic planning and behavioural flexibility. Dendrobatid frogs have evolved a remarkable diversity of parental behaviours. The most noticeable of these behaviours is tadpole transport, which is obligatory in almost all species. Nonetheless, there is limited knowledge about spatial and temporal patterns of tadpole transport and the possible existence of behavioural plasticity on the individual level. In this study, we investigated correlates of tadpole transport behaviour in a natural population of the dendrobatid frog Allobates femoralis during five years. Results: Tadpole transport was predominantly observed during morning hours. Although tadpoles were carried almost exclusively by males (N = 119), we also observed ten females performing this task. The parentage analysis revealed that in all cases females transported their own offspring. In contrast, four tadpole-carrying males were not the genetic fathers of the larvae they were transporting. The average clutch size of 20 eggs and our observation of an average of 8 tadpoles on the back of transporting individuals indicate that frogs do not carry entire clutches at once, and/or that they distribute their larvae across several water bodies. Contrary to the predictions from a hypothetical random search for deposition sites, the number of transported tadpoles was higher in males that travelled over longer distances. Conclusions: Our results suggest a strong selective pressure on males to shift the time invested in tadpole transport to periods of low intra-specific competition. The number of tadpoles on the back of the males significantly correlated with displacement distance from the respective home territories, indicating a strategic non-random tadpole transport rather than random search for suitable tadpole deposition sites during tadpole transport. The observation of females who occasionally transported larvae supports the prevalence of adaptive plasticity in parental behaviours even in a species with a rather low level of parental care.
Pool choice in a vertical landscape: tadpole rearing site flexibility in phytotelm-breeding frogs
2021
Many species of Neotropical frogs have evolved to deposit their tadpoles in small water bodies inside plant structures called phytotelmata. These pools are small enough to exclude large predators but have limited nutrients and high desiccation risk. Here, we explore phytotelm use by three common Neotropical species: Osteocephalus oophagus, an arboreal frog that periodically feeds eggs to its tadpoles; Dendrobates tinctorius, a tadpole-transporting poison frog with cannibalistic tadpoles; and Allobates femoralis, a terrestrial tadpole-transporting poison frog with omnivorous tadpoles. We found that D. tinctorius occupies pools across the chemical and vertical gradient, whereas A. femoralis and O. oophagus appear to have narrower niches that are restricted primarily by pool height, water capacity, alkalinity, and salinity. Dendrobates tinctorius tadpoles are particularly flexible, and can survive in a wide range of chemical, physical, and biological conditions, whereas O. oophagus see...
Nest-site selection in a terrestrially breeding frog with protracted development
Australian Journal of Zoology, 2002
Metamorphosis of larvae of the Australian moss frog (Bryobatrachus nimbus) occurs in a terrestrial nest approximately one year after oviposition. Neither parent attends the eggs, thus selection of an appropriate nest site is critical to egg viability. This study examined the dynamics of nest-site utilisation over six years and the characteristics of nests chosen as oviposition sites. Nest cavities were located at ground level amongst heath within one of 10 species of bryophyte, lichen and lycopod. On average, 2.6% of nests contained a male B. nimbus during daytime monitoring during the breeding season, and 7.3% of nests contained an egg mass. Despite an abundance of potentially suitable nests from previous years, males constructed a small proportion (<10%) of new nests each year and new nests were more likely to be used as oviposition sites than older nests. Discriminant function analysis showed that moss nests used as oviposition sites were distinguishable from empty nests by th...
2018
Phenotypic trait variation among populations is frequently studied to explore evolutionary mechanisms of adaptation processes. However, most studies are conducted over large spatial scales making gene flow between organisms unlikely. Here we explored differentiation of developmental traits among individuals within a small spatial area and asked if differences were environmentally induced and / or had a genetic basis. In a common garden approach we compared the development of Rana temporaria tadpoles, developing either in ponds where the clutch had been originally deposited or in alternative ponds. Forest ponds were small to medium sized, geographically close, and all used as breeding sites by the species. Our main findings were: The variation among pond characteristics was sufficient to generate differences in larval developmental traits among ponds. Non-sibling tadpoles developing in a common environment differed in developmental traits. Sibling tadpoles developing under different ...
Costs and benefits of temporary egg desertion in a rocky shore frog with male-only care
Behavioral Ecology and Sociobiology, 2016
Egg attendance imposes costs on parents, including decreased food intake and increased mortality risks. By concentrating parental activities when egg predation is greater and abiotic conditions are less stressful, parents may decrease these costs. Here, we quantify the costs and benefits of temporary egg desertion in the frog Thoropa taophora, whose males care for eggs on rocky shores. We tested hypotheses on the effect of the period of the day (day vs. night) and breeding site (exposed vs. protected from sunlight) on the frequency of temporary desertion, water loss, and egg predation. Using naturalistic observations, we show that parental males deserted their clutches more often during daytime and in exposed sites. Using a field experiment with agar models simulating adult males, we show that water loss was greater during daytime and in exposed sites. Finally, using field observations and a male removal experiment, we show that male presence improves egg survival and that egg predation was higher during the night, with no effect of breeding site. Because the main egg predators are conspecifics, which are mostly inactive when parental males are not attending their clutches, the costs of temporary desertion in terms of egg loss are relatively low when compared with the benefits related to decreased exposure of parental males to stressful abiotic conditions. In conclusion, we predict that temporary offspring desertion should be found especially among ectotherms, when periods of harsher environmental abiotic conditions for the parents are coincident with periods of low offspring demand for protection against predators. Significance Statement To take care of eggs is costly for the parents because they are exposed to predators or stressful environmental conditions. In order to avoid these costs, parents may leave the eggs temporarily unattended. Although temporary egg desertion has been reported for many species, the selective forces favoring its evolution are still poorly understood. Here, we investigated the costs and benefits of temporary egg desertion in a frog whose males care for eggs on rocky shores, an extreme environment for animals with permeable skin. Our findings lead us to conclude that temporary egg desertion should evolve when periods of harsher environmental conditions for the parents are coincident with periods of low offspring demand for protection against predators.
Herpetologica, 2008
Breeding success of frogs depends, among other factors, on male and female habitat choices, which may be based in part on environmental features that aid offspring survivorship and development. Frogs can respond to habitat features in varied scales, including types of bodies of water and microhabitats within them, and the correspondence between male and female choices may contribute to a successful reproduction. We compared habitat and microhabitat choices by males and females of a Scinax species from the catharinae clade, focusing on microhabitat selection by both sexes, including variation between dry and wet seasons. We also compared the distribution of males and females across a stream size gradient and related their abundance with numbers of tadpoles in each stream to assess successful breeding. We found males and females to be similar in microhabitat preferences, but their abundances did not correlate across streams. Male abundance, however, correlated with number of tadpoles, indicating that number of females may have been underestimated due to their shorter permanence at breeding sites or lower detection probability. Competition and predation did not seem to influence distribution of Scinax gr. catharinae among streams. Male and female Scinax gr. catharinae seem to show highly coordinated responses when selecting breeding habitats and microhabitats, apparently resulting in high breeding success at the study site.
Animal Behaviour, 2016
The ability to differentiate between one's own and foreign offspring ensures the exclusive allocation of costly parental care to only related progeny. The selective pressure to evolve offspring discrimination strategies is largely shaped by the likelihood and costs of offspring confusion. We hypothesize that males and females with different reproductive and spatial behaviours face different risks of confusing their own with others' offspring, and this should favour differential offspring discrimination strategies in the two sexes. In the brilliant-thighed poison frog, Allobates femoralis, males and females are highly polygamous, terrestrial clutches are laid in male territories and females abandon the clutch after oviposition. We investigated whether males and females differentiate between their own offspring and unrelated young, whether they use direct or indirect cues and whether the concurrent presence of their own clutch is essential to elicit parental behaviours. Males transported tadpoles regardless of location or parentage, but to a lesser extent in the absence of their own clutch. Females discriminated between clutches based on exact location and transported tadpoles only in the presence of their own clutch. This sex-specific selectivity of males and females during parental care reflects the differences in their respective costs of offspring confusion, resulting from differences in their spatial and reproductive behaviours.