6 research outputs found
Data from: Broad and flexible stable isotope niches in invasive non-native Rattus spp. in anthropogenic and natural habitats of central eastern Madagascar
Background: Rodents of the genus Rattus are among the most pervasive and successful invasive species, causing major vicissitudes in native ecological communities. A broad and flexible generalist diet has been suggested as key to the invasion success of Rattus spp. Here, we use an indirect approach to better understand foraging niche width, plasticity, and overlap within and between introduced Rattus spp. in anthropogenic habitats and natural humid forests of Madagascar. Results: Based on stable carbon and nitrogen isotope values measured in hair samples of 565 individual rodents, we found that R. rattus had an extremely wide foraging niche, encompassing the isotopic space covered by a complete endemic forest-dwelling Malagasy small mammal community. Comparisons of Bayesian standard ellipses, as well as (multivariate) mixed-modeling analyses, revealed that the stable isotope niche of R. rattus tended to change seasonally and differed between natural forests and anthropogenic habitats, indicating plasticity in feeding niches. In co-occurrence, R. rattus and R. norvegicus partitioned feeding niches. Isotopic mismatch of signatures of individual R. rattus and the habitat in which they were captured, indicate frequent dispersal movements for this species between natural forest and anthropogenic habitats. Conclusions: Since R. rattus are known to transmit a number of zoonoses, potentially affecting communities of endemic small mammals, as well as humans, these movements presumably increase transmission potential. Our results suggest that due to their generalist diet and potential movement between natural forest and anthropogenic habitats, Rattus spp. might affect native forest-dependent Malagasy rodents as competitors, predators, and disease vectors. The combination of these effects helps explain the invasion success of Rattus spp. and the detrimental effects of this genus on the endemic Malagasy rodent fauna
Broad and flexible stable isotope niches in invasive non-native Rattus spp. in anthropogenic and natural habitats of central eastern Madagascar
Abstract Background Rodents of the genus Rattus are among the most pervasive and successful invasive species, causing major vicissitudes in native ecological communities. A broad and flexible generalist diet has been suggested as key to the invasion success of Rattus spp. Here, we use an indirect approach to better understand foraging niche width, plasticity, and overlap within and between introduced Rattus spp. in anthropogenic habitats and natural humid forests of Madagascar. Results Based on stable carbon and nitrogen isotope values measured in hair samples of 589 individual rodents, we found that Rattus rattus had an extremely wide foraging niche, encompassing the isotopic space covered by a complete endemic forest-dwelling Malagasy small mammal community. Comparisons of Bayesian standard ellipses, as well as (multivariate) mixed-modeling analyses, revealed that the stable isotope niche of R. rattus tended to change seasonally and differed between natural forests and anthropogenic habitats, indicating plasticity in feeding niches. In co-occurrence, R. rattus and Rattus norvegicus partitioned feeding niches. Isotopic mismatch of signatures of individual R. rattus and the habitat in which they were captured, indicate frequent dispersal movements for this species between natural forest and anthropogenic habitats. Conclusions Since R. rattus are known to transmit a number of zoonoses, potentially affecting communities of endemic small mammals, as well as humans, these movements presumably increase transmission potential. Our results suggest that due to their generalist diet and potential movement between natural forest and anthropogenic habitats, Rattus spp. might affect native forest-dependent Malagasy rodents as competitors, predators, and disease vectors. The combination of these effects helps explain the invasion success of Rattus spp. and the detrimental effects of this genus on the endemic Malagasy rodent fauna
Raw stable carbon (d13C) and stable nitrogen (d15N) data in ‰ of Rattus rattus and Rattus norvegicus
Raw stable carbon (d13C) and stable nitrogen (d15N) data in ‰ of Rattus rattus and Rattus norvegicu
Data from: Phylogeography and support vector machine classification of colour variation in panther chameleons
Lizards and snakes exhibit colour variation of adaptive value for thermoregulation, camouflage, predator avoidance, sexual selection and speciation. Furcifer pardalis, the panther chameleon, is one of the most spectacular reptilian endemic species in Madagascar, with pronounced sexual dimorphism and exceptionally large intraspecific variation in male coloration. We perform here an integrative analysis of molecular phylogeography and colour variation after collecting high-resolution colour photographs and blood samples from 324 F. pardalis individuals in locations spanning the whole species distribution. First, mitochondrial and nuclear DNA sequence analyses uncover strong genetic structure among geographically restricted haplogroups, revealing limited gene flow among populations. Bayesian coalescent modelling suggests that most of the mitochondrial haplogroups could be considered as separate species. Second, using a supervised multiclass support vector machine approach on five anatomical components, we identify patterns in 3D colour space that efficiently predict assignment of male individuals to mitochondrial haplogroups. We converted the results of this analysis into a simple visual classification key that can assist trade managers to avoid local population overharvesting
Phylogeography and support vector machine classification of colour variation in panther chameleons
Lizards and snakes exhibit colour variation of adaptive value for thermoregulation, camouflage, predator avoidance, sexual selection and speciation. Furcifer pardalis , the panther chameleon, is one of the most spectacular reptilian endemic species in Madagascar, with pronounced sexual dimorphism and exceptionally large intraspecific variation in male coloration. We perform here an integrative analysis of molecular phylogeography and colour variation after collecting high‐resolution colour photographs and blood samples from 324 F. pardalis individuals in locations spanning the whole species distribution. First, mitochondrial and nuclear DNA sequence analyses uncover strong genetic structure among geographically restricted haplogroups, revealing limited gene flow among populations. Bayesian coalescent modelling suggests that most of the mitochondrial haplogroups could be considered as separate species. Second, using a supervised multiclass support vector machine approach on five anatomical components, we identify patterns in 3D colour space that efficiently predict assignment of male individuals to mitochondrial haplogroups. We converted the results of this analysis into a simple visual classification key that can assist trade managers to avoid local population overharvesting