Browsing All Posts filed under »amphibians«

Mosquitofish threaten frogs

September 25, 2017


The mosquitofish, Gambusia holbrooki, is one of the most invasive freshwater fish species in the world.  Although it’s been widely introduced for mosquito control, it has a broad diet that includes algae, higher plants, detritus, invertebrates and fish.  As a result, the species has negative predatory and competitive effects on native fish.   Although declines in […]

Stocking up on threatened amphibians

March 27, 2017

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Zoos have an important role to play in helping to conserve globally threatened species and building public awareness of biodiversity issues. Following massive declines in recent decades, amphibians are now one of the most vulnerable animal groups, with over 40% of all amphibian species classified as threatened. Despite this collapse, relatively few threatened amphibians are […]

Deciding on sites for conservation

December 13, 2016

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Biodiversity conservation is hampered by the fact that many species haven’t been described and most species ranges haven’t been mapped. As a result, in selecting sites for protection, natural resource managers often resort to the use of surrogate indicators for the species that they wish to conserve. Surrogates may be other, more common, species, or […]

The dynamics of habitat choice: alien predators stifle amphibian breeding

June 1, 2016

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The way that animals select habitats reflects their need to balance the costs and benefits associated with factors such as food availability and predation risk. Therefore, habitat choices should vary in response to changes in these key factors. As an example, amphibians are expected to continually adjust the relative amounts of time that they spend […]

Do pollutants bar amphibians from stormwater ponds?

December 18, 2015

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Because of the complex array of ecologically threatening processes in urban environments, our understanding of the role that artificial ponds play in allowing aquatic populations to persist in towns and cities is quite limited. Together with green roofs, swales and stream buffers, stormwater ponds are key instruments in runoff management, but by retaining sediment as […]

How trees affect amphibians

July 20, 2015

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Temporary (seasonal) ponds are the main type of habitat for many aquatic species. Because of the ecological links between freshwater and terrestrial environments, disturbances in the vicinity of temporary ponds can threaten aquatic species. For example, dispersing amphibians may find it difficult to cross open habitats created by the removal of trees. At the same […]

Assessing abundance when animals are hard to find

October 1, 2014

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Aquatic animals are typically sampled by nets, by electrofishing or by snorkeling. Monitoring the status of rare, secretive and threatened species can be problematic because of the relatively high costs of intensive field surveys, and because there may be prohibitions on trapping or handling. A new and promising alternative approach relies on the fact that […]