127 research outputs found
Is Chytridiomycosis an Emerging Infectious Disease in Asia?
The disease chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), has caused dramatic amphibian population declines and extinctions in Australia, Central and North America, and Europe. Bd is associated with >200 species extinctions of amphibians, but not all species that become infected are susceptible to the disease. Specifically, Bd has rapidly emerged in some areas of the world, such as in Australia, USA, and throughout Central and South America, causing population and species collapse. The mechanism behind the rapid global emergence of the disease is poorly understood, in part due to an incomplete picture of the global distribution of Bd. At present, there is a considerable amount of geographic bias in survey effort for Bd, with Asia being the most neglected continent. To date, Bd surveys have been published for few Asian countries, and infected amphibians have been reported only from Indonesia, South Korea, China and Japan. Thus far, there have been no substantiated reports of enigmatic or suspected disease-caused population declines of the kind that has been attributed to Bd in other areas. In order to gain a more detailed picture of the distribution of Bd in Asia, we undertook a widespread, opportunistic survey of over 3,000 amphibians for Bd throughout Asia and adjoining Papua New Guinea. Survey sites spanned 15 countries, approximately 36° latitude, 111° longitude, and over 2000 m in elevation. Bd prevalence was very low throughout our survey area (2.35% overall) and infected animals were not clumped as would be expected in epizootic events. This suggests that Bd is either newly emerging in Asia, endemic at low prevalence, or that some other ecological factor is preventing Bd from fully invading Asian amphibians. The current observed pattern in Asia differs from that in many other parts of the world
Reading tea leaves worldwide: decoupled drivers of initial litter decomposition massâloss rate and stabilization
The breakdown of plant material fuels soil functioning and biodiversity. Currently, process understanding of global decomposition patterns and the drivers of such patterns are hampered by the lack of coherent largeâscale datasets. We buried 36,000 individual litterbags (tea bags) worldwide and found an overall negative correlation between initial massâloss rates and stabilization factors of plantâderived carbon, using the Tea Bag Index (TBI). The stabilization factor quantifies the degree to which easyâtoâdegrade components accumulate during earlyâstage decomposition (e.g. by environmental limitations). However, agriculture and an interaction between moisture and temperature led to a decoupling between initial massâloss rates and stabilization, notably in colder locations. Using TBI improved massâloss estimates of natural litter compared to models that ignored stabilization. Ignoring the transformation of dead plant material to more recalcitrant substances during earlyâstage decomposition, and the environmental control of this transformation, could overestimate carbon losses during early decomposition in carbon cycle models
The program for biodiversity research in Brazil: The role of regional networks for biodiversity knowledge, dissemination, and conservation.
The Program for Biodiversity Research (PPBio) is an innovative program designed to integrate all biodiversity research stakeholders. Operating since 2004, it has installed long-term ecological research sites throughout Brazil and its logic has been applied in some other southern-hemisphere countries. The program supports all aspects of research necessary to understand biodiversity and the processes that affect it. There are presently 161 sampling sites (see some of them at Supplementary Appendix), most of which use a standardized methodology that allows comparisons across biomes and through time. To date, there are about 1200 publications associated with PPBio that cover topics ranging from natural history to genetics and species distributions. Most of the field data and metadata are available through PPBio web sites or DataONE. Metadata is available for researchers that intend to explore the different faces of Brazilian biodiversity spatio-temporal variation, as well as for managers intending to improve conservation strategies. The Program also fostered, directly and indirectly, local technical capacity building, and supported the training of hundreds of undergraduate and graduate students. The main challenge is maintaining the long-term funding necessary to understand biodiversity patterns and processes under pressure from global environmental changes
An illustrated key to tadpoles occurring in the Central Amazon rainforest, Manaus, Amazonas, Brazil
Colour descriptions and life history notes are included. Ecological characteristics of the tadpole community are discussed. -from Autho
Daily behaviour and microhabitat use of the waterfall frog Litoria nannotis in Tully Gorge, Eastern Australia
[Extract] The daily activities of amphibians are influenced by their need to obtain food, mates and shelter, avoid predators, and maintain adequate physiological conditions (Dole, 1965; Beshkov and Jameson, 1980; Wool-bright, 1985; Zug, 1993; Cohen and Alford, 1996; De Oliveira, 1996). Most amphibians share certain behavioral similarities. Because of the permeability of their skin, they are highly susceptible to dehydration from evaporative water loss. Therefore most amphibians are typically nocturnal and tend to shelter in moist refuges during the day and become active only at night (Duellman and Trueb, 1986)
Seasonal sexual and ontogenetic variations in the diet of the 'declining' frogs Litoria nannotis, Litoria rheocola and Nyctimystes dayi
Faecal analyses were used to investigate the diets of the endangered frogs Litoria nannotis, L. rheocola and Nyctimystes dayi in Tully Gorge, North Queensland. Comparisons of diet and food availability indicate that thesespecies feed indiscriminately on a range of terrestrial and aquatic invertebrates. Changes in morphology and foraging behaviour significantly influenced diet composition and created subtle shifts in the degree of selectivity displayed in prey choice. Interspecific differences in numeric and volumetric diet composition were attributed to variations in gape size and microhabitat selection. Within the diets of L. nannotis and L. rheocola, a decline in prey selectivity observed during the dry season reflected a reduction in foraging activity. Differences in the gape size and foraging behaviour of males and females of L. nannotis were responsible for sex-specific differences in diet composition. L. nannotis also diplayed an ontogenetic shift in prey size and type. As snout-vent length increased, L. nannotis consumed fewer, but larger prey and increasingly discriminated against dipterans, dipteran larvae and hemipterans. Importantly, L. nannotis, L. rheocola and N. dayi demonstrated the capacity to compensate for fluctuations in food availability by feeding on less lucrative prey
Platymantis vitiana (Fiji Ground Frog). Froglet Morphology
Griffith Sciences, Griffith School of EnvironmentFull Tex
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