Sound radiation patterns have ecological implications in the effective communication between cons... more Sound radiation patterns have ecological implications in the effective communication between conspecifics, like optimization of the sound propagation, increase the likelihood to reach mates and to mitigate effects of sound scattering by environmental factors like vegetation. The territorial frog Allobates femoralis advertises its territory against conspecific males and attract females with advertisement calls. Here we report the nearly omnidirectional sound-radiation pattern of the advertisement call of A. femoralis. This sound spreading pattern allows the males to attract mates and repel rivals in all directions. Furthermore, A. femoralis males direct the advertisement call to conspecific neighbours after phonotactic orientation.
Amazonian lowland rainforests epitomize, as few other biomes, the terrestrial and freshwater biol... more Amazonian lowland rainforests epitomize, as few other biomes, the terrestrial and freshwater biological diversity of our planet. We provide here a comprehensive description of the larval anurans of Central Amazonia, and their natural history. We base our analyses on fieldwork conducted in six terra-firme rainforest and two várzea floodplain sites during ~60 months between 1990 and 2013, complemented with an examination of museum specimens and a review of published literature. Ninety-nine species of anurans are known to occur in Central Amazonia. Of these, 84 species (85%) have a free-swimming exotrophic larva, six species (6%) have a terrestrial endotrophic larva, one species has a terrestrial exotrophic larva (1%) and another seven species (7%) have direct development of eggs into froglets. The life cycle of one species (1%) remains unknown. We formally describe and illustrate the larval stage of 68 species (i.e., 75% of the species with a known larval stage), five of them previously unkown and nineteen never described for Central Amazonia. We compile, review and update information on species natural history including reproductive modes, habitat use, phenology, and species interactions including diet, predators, competitors and parasites. Finally, we assessed the ecomorphological diversity in the region by the application of a system inspired in Altig & Johnston (1989), later updated by Altig & McDiarmid (1999), which recognizes tadpole guilds based on a combination of morphological and natural history data. Basic scientific information presented in this monograph provide the essential background for further studies on the ecological and evolutionary forces shaping anuran Amazonian assemblages, and their conservation.
Most animals move in dense habitats where distant landmarks are limited, but how they find their ... more Most animals move in dense habitats where distant landmarks are limited, but how they find their way around remains poorly understood. Poison frogs inhabit the rainforest understory where they shuttle tadpoles from small territories to widespread pools. Recent studies revealed their excellent spatial memory and the ability to home back from several hundred meters. It remains unclear if this homing ability is restricted to the areas that had been previously explored or if it allows the frogs to navigate from areas outside their direct experience. Here we used radio-tracking to study the navigational performance of three-striped poison frog translocated outside the area of their routine movements (200 – 800 m). Translocated frogs returned to their home territory via a direct path from all distances and with little difference in orientation accuracy, suggesting a flexible map-like navigation mechanism. These findings challenge our current understanding of mechanisms and the sensory bas...
Surveys of 62 pond sites near Market-Drayton, Shropshire, were carried out in September 1989 and ... more Surveys of 62 pond sites near Market-Drayton, Shropshire, were carried out in September 1989 and April-September 1993 to determine the local distribution of the alpine newt Triturus alpestris, first introduced there in 1970-74. Triturus alpestris was found in garden and farm ponds up to 70m from the original sites of liberation. Relative numbers and size-ranges of adult and larval Triturus species (alpestris, cristatus, vulgaris) are compared between study areas. The ecological and conservation implications of T. alpestris in Britain are discussed.
The Journal of the Acoustical Society of America, 2020
The males of the brilliant-thighed poison frog, Allobates femoralis, are known to present stereot... more The males of the brilliant-thighed poison frog, Allobates femoralis, are known to present stereotypic phonotactic responses to the playback of conspecific and synthetic calls. Fixed site attachment and a long calling period render this terrestrial and diurnal pan-Amazonian frog a rewarding species for bioacoustics. Several aspects of field bioacoustics in A. femoralis have been studied by the author's research team during the last 35 years such as the influence of temporal and spectral variation of the advertisement call on phonotactic responses. A clear difference in the phonotactic behaviour was found in populations with or without a co-occuring species presenting an overlap in the frequency range. With the use of a robot frog it could be shown that a combination of acoustic and a visual signal is necessary to elicit agonistic behaviour in this highly territorial species. In A. femoralis obligatory tadpole transport is generally performed by males, whereas females abandon thei...
Carotenoids play an import role as one of the most prevalent pigments in animals. Carotenoid-base... more Carotenoids play an import role as one of the most prevalent pigments in animals. Carotenoid-based colourations account for striking sexually and naturally selected colour adaptations. Several anurans (frogs and toads) change body coloration either slowly and permanently between life stages (ontogenetic colour change), or rapidly and temporarily (dynamic colour change) within minutes or hours. We investigated ontogenetic colour change from orange to green morphs and tested the influence of dietary carotenoids in the Wallace's flying frog, Rhacophorus nigropalmatus. Conspicuous orange-red colouration in post-metamorphic development and formation of whitish dorsal spots only present in early life stages suggest juveniles imitate bird droppings. At the age of nine months, while all individuals still possessed orange-red body colouration, a 20-week long feeding experiment was performed supplying frogs with either no carotenoid supplementations, or dietary carotenoids once or four times per week. A high carotenoid diet resulted in a faster increase in green colour saturation and high levels of green and yellow chroma of back colouration. Less or no carotenoid supplementation led to an increase in blue chroma, contributing to a dull turquoise appearance often observed in captive bred and raised anurans. Dietary carotenoid availability in early life stages affected adaptive dynamic colour change when exposed to a mild stressor. Our results show that a high carotenoid diet influenced the ability to rapidly and reversibly change body colouration, an adaptation absent in frogs receiving no carotenoids. Dynamic colour changes were likewise performed in response to changing light conditions presumably camouflaging individuals and providing protection from UV irradiation. The ontogenetic and dynamic pigmentation changes are discussed in light of mechanism and function to promote defensive strategies at different life stages and environments to avoid predation. Description of dataset The four datasets contain following colour [...]
Here we document the development of seven novel polymorphic microsatellite markers for the brilli... more Here we document the development of seven novel polymorphic microsatellite markers for the brilliant-thighed poison frog Allobates femoralis (Dendrobatidae). We found between six and 27 alleles per locus in 100 individuals (50 males, 50 females) from the field site 'Saut Pararé', French Guiana, with an average observed heterozygosity of 0.79. One locus (Afem23) deviated significantly from Hardy-Weinberg equilibrium. We did not find any evidence for linkage disequilibrium among the new loci, or to seven of the already described markers for A. femoralis. We also report cross-species amplification of some of the markers in three other dendrobatid species (A. talamancae, Dendrobates tinctorius and Oophaga pumilio).
Sound radiation patterns have ecological implications in the effective communication between cons... more Sound radiation patterns have ecological implications in the effective communication between conspecifics, like optimization of the sound propagation, increase the likelihood to reach mates and to mitigate effects of sound scattering by environmental factors like vegetation. The territorial frog Allobates femoralis advertises its territory against conspecific males and attract females with advertisement calls. Here we report the nearly omnidirectional sound-radiation pattern of the advertisement call of A. femoralis. This sound spreading pattern allows the males to attract mates and repel rivals in all directions. Furthermore, A. femoralis males direct the advertisement call to conspecific neighbours after phonotactic orientation.
Amazonian lowland rainforests epitomize, as few other biomes, the terrestrial and freshwater biol... more Amazonian lowland rainforests epitomize, as few other biomes, the terrestrial and freshwater biological diversity of our planet. We provide here a comprehensive description of the larval anurans of Central Amazonia, and their natural history. We base our analyses on fieldwork conducted in six terra-firme rainforest and two várzea floodplain sites during ~60 months between 1990 and 2013, complemented with an examination of museum specimens and a review of published literature. Ninety-nine species of anurans are known to occur in Central Amazonia. Of these, 84 species (85%) have a free-swimming exotrophic larva, six species (6%) have a terrestrial endotrophic larva, one species has a terrestrial exotrophic larva (1%) and another seven species (7%) have direct development of eggs into froglets. The life cycle of one species (1%) remains unknown. We formally describe and illustrate the larval stage of 68 species (i.e., 75% of the species with a known larval stage), five of them previously unkown and nineteen never described for Central Amazonia. We compile, review and update information on species natural history including reproductive modes, habitat use, phenology, and species interactions including diet, predators, competitors and parasites. Finally, we assessed the ecomorphological diversity in the region by the application of a system inspired in Altig & Johnston (1989), later updated by Altig & McDiarmid (1999), which recognizes tadpole guilds based on a combination of morphological and natural history data. Basic scientific information presented in this monograph provide the essential background for further studies on the ecological and evolutionary forces shaping anuran Amazonian assemblages, and their conservation.
Most animals move in dense habitats where distant landmarks are limited, but how they find their ... more Most animals move in dense habitats where distant landmarks are limited, but how they find their way around remains poorly understood. Poison frogs inhabit the rainforest understory where they shuttle tadpoles from small territories to widespread pools. Recent studies revealed their excellent spatial memory and the ability to home back from several hundred meters. It remains unclear if this homing ability is restricted to the areas that had been previously explored or if it allows the frogs to navigate from areas outside their direct experience. Here we used radio-tracking to study the navigational performance of three-striped poison frog translocated outside the area of their routine movements (200 – 800 m). Translocated frogs returned to their home territory via a direct path from all distances and with little difference in orientation accuracy, suggesting a flexible map-like navigation mechanism. These findings challenge our current understanding of mechanisms and the sensory bas...
Surveys of 62 pond sites near Market-Drayton, Shropshire, were carried out in September 1989 and ... more Surveys of 62 pond sites near Market-Drayton, Shropshire, were carried out in September 1989 and April-September 1993 to determine the local distribution of the alpine newt Triturus alpestris, first introduced there in 1970-74. Triturus alpestris was found in garden and farm ponds up to 70m from the original sites of liberation. Relative numbers and size-ranges of adult and larval Triturus species (alpestris, cristatus, vulgaris) are compared between study areas. The ecological and conservation implications of T. alpestris in Britain are discussed.
The Journal of the Acoustical Society of America, 2020
The males of the brilliant-thighed poison frog, Allobates femoralis, are known to present stereot... more The males of the brilliant-thighed poison frog, Allobates femoralis, are known to present stereotypic phonotactic responses to the playback of conspecific and synthetic calls. Fixed site attachment and a long calling period render this terrestrial and diurnal pan-Amazonian frog a rewarding species for bioacoustics. Several aspects of field bioacoustics in A. femoralis have been studied by the author's research team during the last 35 years such as the influence of temporal and spectral variation of the advertisement call on phonotactic responses. A clear difference in the phonotactic behaviour was found in populations with or without a co-occuring species presenting an overlap in the frequency range. With the use of a robot frog it could be shown that a combination of acoustic and a visual signal is necessary to elicit agonistic behaviour in this highly territorial species. In A. femoralis obligatory tadpole transport is generally performed by males, whereas females abandon thei...
Carotenoids play an import role as one of the most prevalent pigments in animals. Carotenoid-base... more Carotenoids play an import role as one of the most prevalent pigments in animals. Carotenoid-based colourations account for striking sexually and naturally selected colour adaptations. Several anurans (frogs and toads) change body coloration either slowly and permanently between life stages (ontogenetic colour change), or rapidly and temporarily (dynamic colour change) within minutes or hours. We investigated ontogenetic colour change from orange to green morphs and tested the influence of dietary carotenoids in the Wallace's flying frog, Rhacophorus nigropalmatus. Conspicuous orange-red colouration in post-metamorphic development and formation of whitish dorsal spots only present in early life stages suggest juveniles imitate bird droppings. At the age of nine months, while all individuals still possessed orange-red body colouration, a 20-week long feeding experiment was performed supplying frogs with either no carotenoid supplementations, or dietary carotenoids once or four times per week. A high carotenoid diet resulted in a faster increase in green colour saturation and high levels of green and yellow chroma of back colouration. Less or no carotenoid supplementation led to an increase in blue chroma, contributing to a dull turquoise appearance often observed in captive bred and raised anurans. Dietary carotenoid availability in early life stages affected adaptive dynamic colour change when exposed to a mild stressor. Our results show that a high carotenoid diet influenced the ability to rapidly and reversibly change body colouration, an adaptation absent in frogs receiving no carotenoids. Dynamic colour changes were likewise performed in response to changing light conditions presumably camouflaging individuals and providing protection from UV irradiation. The ontogenetic and dynamic pigmentation changes are discussed in light of mechanism and function to promote defensive strategies at different life stages and environments to avoid predation. Description of dataset The four datasets contain following colour [...]
Here we document the development of seven novel polymorphic microsatellite markers for the brilli... more Here we document the development of seven novel polymorphic microsatellite markers for the brilliant-thighed poison frog Allobates femoralis (Dendrobatidae). We found between six and 27 alleles per locus in 100 individuals (50 males, 50 females) from the field site 'Saut Pararé', French Guiana, with an average observed heterozygosity of 0.79. One locus (Afem23) deviated significantly from Hardy-Weinberg equilibrium. We did not find any evidence for linkage disequilibrium among the new loci, or to seven of the already described markers for A. femoralis. We also report cross-species amplification of some of the markers in three other dendrobatid species (A. talamancae, Dendrobates tinctorius and Oophaga pumilio).
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