May 24 2012

5:00 pm 154 BSRB

EcoEvoPub Series

Graduate Student Presentations


Department of Ecology and Evolutionary Biology

“The effects of Heterospecific Aggression on Winter Habitat Use in a Migrant and Resident Passerine”

In neotropical migratory birds, the effects of competition are usually studied during the breeding season. On the wintering grounds, competition with conspecifics has known effects on body condition and migration date, affecting breeding success and thus fitness. However, the effects of interspecific interference competition(where ecologically similar species compete for shared, defendable resources) have rarely been studied. I will address this topic by presenting data on heterospecific aggression, territory size, and habitat use in sympatric populations of two vireo species, and describe preliminary analyses from allopatric populations.

Department of Ecology and Evolutionary Biology

“Connectivity of a patchy Mojave Desert shrub: examining landscape genetics at multiple spatial scales”

The influence of landscape on movement is an essential part of understanding the mechanisms and limitations of dispersal. In a changing habitat this informs predictions of future response to a variable environment. New tools using graphical and multivariate statistics have increased our ability to identify more nuanced sub-structuring patterns that are often concealed by basic F-statistics. This study examines Acacia greggii A Gray in the Mojave National Preserve, a patchy desert shrub whose movement is likely influenced by several landscape features. We found this species is well connected regionally (>2km) but locally (<2km) more restricted. Using new genetic tools, we found dry washes explain local genetic pattern, serving as corridors of movement during infrequent rainfall, but creating directional gene-flow and structuring local populations. Additionally, we found genetic variation was highly correlated with elevation at all spatial scales. This is possibly due to elevational adaptation or pollinator movement patterns. This study demonstrates the effectiveness of using novel genetic tools to identify the relationship between landscape and genetic patterns.

THURSDAY, MAY 24, 2012















































































































































































































































































































































































































































































































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