Behavior and Ethology Commons^™

Beyond Predation: How Do Consumers Mediate Bottom-Up Processes In Ecosystems?, Bradley Austin Strickland

FIU Electronic Theses and Dissertations

By eating and scaring prey, predators can exert strong effects on communities and ecosystems. In addition, some animals may physically alter habitats and may recycle nutrients through digestion, both of which affect resources available to producers. Bottom-up effects initiated by large predators have not been well-studied and could prove to be important for understanding food webs and how ecosystems function. American alligators (Alligator mississippiensis) are abundant mobile predators that are capable of engineering aquatic habitats by moving organic material across ecosystem boundaries and creating and maintaining alligator ponds. In this dissertation, I documented the scale of ecological impacts …

Using Introduced Species Of Anolis Lizards To Test Adaptive Radiation Theory, James T. Stroud

FIU Electronic Theses and Dissertations

Adaptive radiation – the proliferation of species from a single ancestor and diversification into many ecologically different forms – has long been heralded as an important process in the generation of phenotypic diversity. However, the early stages of adaptive radiation are notoriously elusive to observe and study. In this dissertation, I capitalize on communities of introduced non-native Anolis lizards as analogues of early stage adaptive radiations. In Chapter II, I begin by reviewing the concept of “ecological opportunity” – a classic hypothesis put forward as a potential key to understanding when and how adaptive radiation occurs. In Chapter III, I …

Examining Movement And Habitat Selection Of Everglades Fishes In Response To Seasonal Water Levels, Gregory J. Hill

FIU Electronic Theses and Dissertations

Fish distribution patterns and seasonal habitat use play a key role in the food web dynamics of aquatic ecosystems, including the Florida Everglades. In this study I examined the fine scale habitat shifts and movements of spotted sunfish, Lepomis punctatus across varying seasons and hydrologic conditions using in-situ field enclosures and Passive Integrated Transponder (PIT) systems. Data on fish use of three dominant Everglades marsh habitats and activity level were recorded continuously from January to August, 2015. Fish were more active and had the highest use of higher elevation habitats when water levels rose during an experimental reversal in mid-April. …

Effects Of Catastrophic Seagrass Loss And Predation Risk On The Ecological Structure And Resilience Of A Model Seagrass Ecosystem, Robert J. Nowicki

FIU Electronic Theses and Dissertations

As climate change continues, climactic extremes are predicted to become more frequent and intense, in some cases resulting in dramatic changes to ecosystems. The effects of climate change on ecosystems will be mediated, in part, by biotic interactions in those ecosystems. However, there is still considerable uncertainty about where and how such biotic interactions will be important in the context of ecosystem disturbance and climactic extremes.

Here, I review the role of consumers in seagrass ecosystems and investigate the ecological impacts of an extreme climactic event (marine heat wave) and subsequent widespread seagrass die-off in Shark Bay, Western Australia. Specifically, …