From British Columbia to northern California, coastal giant salamanders (Dicamptodon tenebrosus) are a dominant vertebrate predator in headwater streams. Though widespread, salamander health and abundance levels differ greatly between locations, provoking the question as to what factors may influence this variation and whether habitat features or biotic variables play a...
Across the globe, Marine Protected Areas (MPAs) have been established to protect biodiversity, sustain fisheries, and preserve cultural resources. However, there exist broad differences among MPAs with respect to their establishment stage and protective regulations, making it difficult to quantify how much ocean protection is actually occurring. This thesis utilizes...
Primate populations are declining in number, with an estimated “60% of primate species threatened with extinction from hunting and trapping” (Estrada et al., 2017). The largest threat to mammals in West and Central Africa is commercial hunting (Jost Robinson, Daspit, & Remis, 2011). Hunting these large mammals was once practiced...
Biological invasions and climate change represent two preeminent threats to ecological communities and biodiversity, altering the distribution and abundance of species, disrupting existing species interactions and forming unprecedented ones, and creating novel ecological communities. Many of the most successful invasive species are also ecosystem engineers, species that physically modify the...
Biological invasions have been identified as one of the prominent drivers of global environmental change. In particular, invasive predators typically have substantial negative effects on populations of native prey, even driving species to extinction in extreme cases. However, beyond direct predatory effects, little is understood regarding the specific mechanisms by...
Climate change is predicted to affect ecosystems, including systems already stressed by human impacts. One ecosystem that is already highly impacted by human land use is the cold headwater stream system of the Pacific Northwest. One method of assessing the function of an ecosystem is by using an indicator species....
The current rate of global biodiversity loss and extinctions is unparalleled and a major concern. Freshwater organisms are facing particularly rapid rates of biodiversity loss. Amphibians, which require an aquatic environment for part of their life cycle, are one of the most vulnerable vertebrate groups. Amphibians are experiencing population declines,...
Rapid rates of biodiversity loss have supported the notion that Earth is experiencing a sixth major extinction event. The causes of worldwide biodiversity loss are multifaceted and context dependent. One of the most prominent groups experiencing population declines and extinctions are amphibians. Several pathogens and their associated diseases are especially...
Coral reproduction is vital to the persistence of coral reefs. Decades of ecological studies have correlated environmental variables, such as temperature and light, to the timing of reproduction in anthozoan cnidarians, including corals and sea anemones. However, elevated temperatures associated with climate change impair reproductive success and threaten the resilience...
Parasitic infections and immune challenges can affect host reproductive fitness and, ultimately, the evolution of host populations in a myriad of ways. The fitness implications of parasitic infections range from increased host mortality to subtle changes in reproductive investment. From alterations of behaviors, sexual signaling, and competitive ability to changes...