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Biodiversity Commons™

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Zoology

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Selected Works

2011

Articles 1 - 2 of 2

Full-Text Articles in Biodiversity

Population Growth Of Mexican Free-Tailed Bats (Tadarida Brasiliensis Mexicana) Predates Human Agricultural Activity, Amy L. Russell, Murray P. Cox, Veronica A. Brown, Gary F. Mccracken Mar 2011

Population Growth Of Mexican Free-Tailed Bats (Tadarida Brasiliensis Mexicana) Predates Human Agricultural Activity, Amy L. Russell, Murray P. Cox, Veronica A. Brown, Gary F. Mccracken

Amy L. Russell

Background: Human activities, such as agriculture, hunting, and habitat modification, exert a significant effect on native species. Although many species have suffered population declines, increased population fragmentation, or even extinction in connection with these human impacts, others seem to have benefitted from human modification of their habitat. Here we examine whether population growth in an insectivorous bat (Tadarida brasiliensis mexicana) can be attributed to the widespread expansion of agriculture in North America following European settlement. Colonies of T. b. mexicana are extremely large (~106 individuals) and, in the modern era, major agricultural insect pests form an important component of their …

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Acute Toxicity Of Mercury And Chromium To Clarias Batrachus (Linn), Azhaguraj Ramakrishnan Jan 2011

Acute Toxicity Of Mercury And Chromium To Clarias Batrachus (Linn), Azhaguraj Ramakrishnan

Azhaguraj Ramakrishnan

Pollution of the aquatic ecosystems by heavy metals is a worldwide problem. In the present study, Clarias batrachus was exposed to Mercury and Chromium for 24, 48, 72 and 96 hrs. The median lethal concentration (LC50) of mercury to C. batrachus for 24, 48, 72 and 96 h of exposure were 1.4 ppm, 1.2 ppm, 1.0 ppm and 0.8 ppm respectively. The median lethal concentration (LC50) of chromium to C. batrachus for 24, 48, 72 and 96 h of exposure were 120 ppm, 115 ppm, 110 ppm and 102 ppm respectively. The acute toxicity levels were derived from LC50 concentrations …

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