Synergistic effects of predators and trematode parasites on larval green frog (Rana clamitans) survival

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/116905/1/ecy201394122697.pd

Lethal And Nonlethal Predator Effects On An Herbivore Guild Mediated By System Productivity

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/117135/1/ecy2006872347.pd

A Review Of Trait‐Mediated Indirect Interactions In Ecological Communities

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/117099/1/ecy20038451083.pd

How Dependent Are Species‐Pair Interaction Strengths On Other Species In The Food Web?

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/117139/1/ecy200485102754.pd

Mechanisms Of Nonlethal Predator Effect On Cohort Size Variation: Ecological And Evolutionary Implications

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/116938/1/ecy20078861536.pd

Natural Selection For Environmentally Induced Phenotypes In Tadpoles

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137452/1/evo05119.pd

Competition and host size mediate larval anuran interactions with trematode parasites

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140008/1/fwb12730.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/140008/2/fwb12730_am.pd

Chronic exposure to fluoxetine (Prozac) causes developmental delays in Rana pipiens larvae

Selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine, are among the many pharmaceuticals detected in aquatic ecosystems. Although the acute effects of SSRIs on select organisms have been reported, little is understood about the chronic effects of these drugs on amphibians, which are particularly sensitive to environmental pollutants. Serotonin plays important roles in many physiological functions, including a wide array of developmental processes. Exposure to SSRIs during development may cause developmental complications in a variety of organisms, but little is known about the degree of exposure necessary to cause deleterious effects. Here, we sought to gain a better understanding of the effects of SSRIs on amphibian development by use of a combined laboratory and outdoor mesocosm study. Tadpoles in a laboratory setting were exposed to a low (0.029 µg/L) and a high (0.29 µg/L) concentration of the common SSRI fluoxetine from stages 21 and 22 through completion of metamorphosis. Tadpoles in outdoor mesocosms were exposed to fluoxetine concentrations ranging from 0.1 to 0.3 µg/L. Exposed tadpoles in the laboratory showed delayed development compared with controls when stage was assessed throughout the experiment. Control tadpoles also gained weight faster than treatment tadpoles, which may be explained by reduced food intake. Mesocosm tadpoles exhibited similar trends, but no significant differences were detected. These results indicate that ecologically relevant levels of fluoxetine may cause developmental delays in amphibians. Environ. Toxicol. Chem. 2010;29:2845–2850. © 2010 SETACPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78304/1/345_ftp.pd

Predictable changes in predation mortality as a consequence of changes in food availability and predation risk

Theory predicts that animals will have lower activity levels when either the risk of predation is high or the availability of resources in the environment is high. If encounter rates with predators are proportional to activity level, then we might expect predation mortality to be affected by resource availability and predator density independent of the number of effective predators. In a factorial experiment, we tested whether predation mortality of larval wood frogs, Rana sylvatica, caused by a single larval dragonfly, Anax junius, was affected by the presence of additional caged predators and elevated resource levels. Observations were consistent with predictions. The survival rate of the tadpoles increased when additional caged predators were present and when additional resources were provided. There was no significant interaction term between predator density and food concentration. Lower predation rates at higher predator density is a form of interference competition. Reduced activity of prey at higher predator density is a potential general mechanism for this widespread phenomenon. Higher predation rates at low food levels provides an indirect mechanism for density-dependent predation. When resources are depressed by elevated consumer densities, then the higher activity levels associated with low resource levels can lead to a positive association between consumer density and consumer mortality due to predation. These linkages between variation in behaviour and density-dependent processes argue that variation in behaviour may contribute to the dynamics of the populations. Because the capture rate of predators depends on the resources available to prey, the results also argue that models of food-web dynamics will have to incorporate adaptive variation in behaviour to make accurate predictions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42739/1/10682_2004_Article_176894.pd

Comparative landscape dynamics of two anuran species: climate‐driven interaction of local and regional processes

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/117162/1/ecm2009793503.pd