February 29 2012

5:00 pm 154 BSRB

EcoEvoPub Series

Graduate Student Presentations


Dept of Ecology and Evolutionary Biology, UCLA
"Anticoagulant Rodenticides: A Big Problem For Local Wildlife?"

Urban and agricultural pesticide use can challenge even those wildlife species that are relatively adaptable to urban development. Understanding the threats poisons pose to wildlife is critical to the conservation of all wildlife species potentially exposed to the poisons. Anticoagulant rodenticides are a globally ubiquitous pesticide and the most common form of rodent control used worldwide. However, the potential sublethal consequences that chronic anticoagulant exposure may pose to wildlife remains unknown. In southern California, along with National Park Service collaborators, we have worked for more than a decade to understand the critical effects local rat poison use is having on native carnivore populations. We are discovering that the effects of exposure to anticoagulant rodenticides ranges from causing direct mortalities in three carnivore species to potentially causing sublethal, immune-related effects in bobcat populations. We are detecting alarming exposure rates for bobcats, mountain lions, and coyotes, and that exposure may begin during prenatal development. I will present what data we have generated already on exposure- data we are presently sharing with the California Department of Pesticide Regulation as they review the effects of these poisons on wildlife Statewide. Understanding the sublethal consequences of anticoagulant exposure will be critical to advancing increased restrictions on the availability of these poisons for use in urban and agricultural areas and promoting the conservation of many vertebrate species.


Dept of Ecology and Evolutionary Biology, UCLA

"Size Variation and Reproductive Strategies in the Sand Wasp/Steniolia Nigripes"

Differences in reproductive tactics and phenotypes are most often explained in the adaptive context of frequency-dependent and condition-dependent selection. However, traditional theories relating ecology and mating systems do not account for the effects that the behavior of one sex can have on the fitness of the other. Sand wasps (Crabronidae: Bembicinae) present a unique opportunity to study the importance of phenotypic variation in sexual interactions, because there is variability in sexual dimorphism and mating behavior across species. In particular, /Steniolia nigripes/ shows reversed sexual size dimorphism and aggressive male defense of food resources visited by females, a behavior previously undescribed in the Bembicinae. Males are larger than females, but body size varies significantly within both sexes. My data indicate that male aggression level and success in territory holding are highly related to body size. Size thus appears to mediate the effectiveness of intrasexual competition in males. Future studies will determine if body size also influences mate choice.











































































































































































































































































































































































































































































































































































































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