Leptodactylus bufonius

Number of Pages: 22Integrative BiologyGeological Science

Lepidobatrachus laevis

Number of Pages: 16Integrative BiologyGeological Science

Activity Level-Predation Risk Tradeoff in a Tadpole Guild: Implications for Community Organization Along the Hydroperiod Gradient

Increasing activity levels permit greater food intake for use towards growth and reproduction, consequently increasing predation risk via increased detection. Larval anurans are models to examine activity level-predation risk tradeoffs, as they occupy a variety of lentic habitats that impose constraints on the distribution and abundance of species. Ephemeral ponds have a low abundance and diversity of predators and as a result tadpole species tend to have high foraging rates for rapid development. Permanent ponds generally possess a greater diversity and abundance of predators and tadpoles inhabiting these locations tend to have low activity rates or chemical defenses to minimize predation risk. The objective of this research was to examine how interspecific variation in activity level and response to predation risk, corresponds to the distributions of tadpole species along the hydroperiod gradient. Furthermore, we examined the intraspecific variation in activity level among the species. We conducted a series of laboratory experiments in which we quantified baseline activity patterns and the change in activity after the addition of a predator or exposure to alarm cues, for 12 species of larval anurans native to East Texas. Species that maintained a high activity level generally occupied ephemeral ponds and species that maintained low activity levels generally occupied permanent ponds. Only one species (Gastrophryne carolinensis) decreased their activity level in the presence of predator cues or conspecific alarm cues. These results highlight this tradeoff can have consequences on the life histories of multiple species, providing insight into how it affects the organization of ecological communities

NSW Great Artesian Basin water market assessment pre and post auction

The NSW Cap & Pipe the Bores Program is a jointly funded Commonwealth and State initiative that operates within the Australian Government's Great Artesian Basin Sustainability Initiative framework. Under the Water Sharing Plan for the NSW Great Artesian Basin Groundwater Sources 2008, 70 per cent of the water savings made since 1999 shall be retained in the aquifers of the Basin to improve pressures and provide for groundwater dependent ecosystems. The remaining 30 per cent of the water savings may be released to extractive users over the term of the Water Sharing Plan to facilitate the continued economic and social welfare of regional western NSW. As the first step in this water release, part of the water savings from the Cap & Pipe the Bores program were auctioned in July 2009 in the western NSW town of Walgett. All lots offered at auction were sold. The study reviews the pre auction analysis of demand, and outlines the auction process and outcomes as well as the implications for future water sales. The outcomes of the auction will inform ongoing water allocation policy.water auction, economics, Great Artesian Basin, groundwater, Cap & Pipe the Bores, Water Sharing Plan., Resource /Energy Economics and Policy,

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Move it or lose it: interspecific variation in risk response of pond-breeding anurans

Changes in behavior are often the proximate response of animals to human disturbance, with variability in tolerance levels leading some species to exhibit striking shifts in life history, fitness, and/or survival. Thus, elucidating the effects of disturbance on animal behavior, and how this varies among taxonomically similar species with inherently different behaviors and life histories is of value for management and conservation. We evaluated the risk response of three anuran species—southern leopard frog (Lithobates sphenocephalus), Blanchard’s cricket frog (Acris blanchardi), and green tree frog (Hyla cinerea)—to determine how differences in microhabitat use (arboreal vs ground-dwelling) and body size (small vs medium) may play a role in response to a potential threat within a human-altered subtropical forest. Each species responded to risk with both flight and freeze behaviors, however, behaviors were species- and context-specific. As distance to cover increased, southern leopard frogs increased freezing behavior, green tree frogs decreased freezing behavior, and Blanchard’s cricket frogs increased flight response. The propensity of green tree frogs to use the canopy of vegetation as refugia, and the small body size of Blanchard’s cricket frogs likely led to greater flight response as distance to cover increased, whereas innate reliance on camouflage among southern leopard frogs may place them at greater risk to landscaping, agricultural, and transportation practices in open terrain. As such, arboreal and small-bodied species may inherently be better suited in human altered-landscapes compared to larger, ground-dwelling species. As land-use change continues to modify habitats, understanding how species respond to changes in their environment continues to be of importance, particularly in ecosystems where human-wildlife interactions are expected to increase in frequency