Life Sciences Commons^™

Fear Effects And Group Size Interact To Shape Herbivory On Coral Reefs, Andrew G. Bauman, Andrew S. Hoey, Glenn Dunshea, Jenny Fong, Ian Z. W. Chan, Peter A. Todd

Marine & Environmental Sciences Faculty Articles

1. Fear of predators (‘fear effects’) is an important determinant of foraging decisions by consumers across a range of ecosystems. Group size is one of the main behavioural mechanisms for mitigating fear effects while also providing foraging benefits to group members. Within coral reef ecosystems, fear effects have been shown to influence the feeding rates of herbivorous fishes, a key functional group that prevents macroalgal overgrowth. Yet, how fear effects and group size interact to shape macroalgal removal on coral reefs remains unclear.
2. Here, we conducted field-based experiments using models of a common piscivorous fish, the leopard coral grouper Plectropomus leopardus …

Fear Effects Associated With Predator Presence And Habitat Structure Interact To Alter Herbivory On Coral Reefs, Andrew G. Bauman, Jovena C. L. Seah, Fraser A. Januchowski-Hartley, Andrew S. Hoey, Jenny Fong, Peter A. Todd

Marine & Environmental Sciences Faculty Articles

Non-consumptive fear effects are an important determinant of foraging decisions by consumers across a range of ecosystems. However, how fear effects associated with the presence of predators interact with those associated with habitat structure remain unclear. Here, we used predator fish models (Plectropomus leopardus) and experimental patches of the macroalga Sargassum ilicifolium of varying densities to investigate how predator- and habitat-associated fear effects influence herbivory on coral reefs. We found the removal of macroalgal biomass (i.e. herbivory) was shaped by the interaction between predator- and habitat-associated fear effects. Rates of macroalgal removal declined with increasing macroalgal density, likely …

Indirect Legacy Effects Of An Extreme Climatic Event On A Marine Megafaunal Community, Robert Nowicki, Michael Heithaus, Jordan Thompson, Derek Burkholder, Kirk Gastrich, Aaron Wirsing

Marine & Environmental Sciences Faculty Articles

While extreme climatic events (ECEs) are predicted to become more frequent, reliably predicting their impacts on consumers remains challenging, particularly for large consumers in marine environments. Many studies that do evaluate ECE effects focus primarily on direct effects, though indirect effects can be equally or more important. Here, we investigate the indirect impacts of the 2011 “Ningaloo Niño” marine heatwave ECE on a diverse megafaunal community in Shark Bay, Western Australia. We use an 18‐year community‐level data set before (1998–2010) and after (2012–2015) the heatwave to assess the effects of seagrass loss on the abundance of seven consumer groups: sharks, …

Top Predators Negate The Effect Of Mesopredators On Prey Physiology, Maria Palacios, Shaun S. Killen, Lauren E. Nadler, James R. White, Mark I. Mccormick

Marine & Environmental Sciences Faculty Articles

1. Predation theory and empirical evidence suggest that top predators benefit the survival of resource prey through the suppression of mesopredators. However, whether such behavioural suppression can also affect the physiology of resource prey has yet to be examined.
2. Using a three‐tier reef fish food web and intermittent‐flow respirometry, our study examined changes in the metabolic rate of resource prey exposed to combinations of mesopredator and top predator cues.
3. Under experimental conditions, the mesopredator (dottyback, Pseudochromis fuscus ) continuously foraged and attacked resource prey (juveniles of the damselfish Pomacentrus amboinensis ) triggering an increase in prey O2 uptake by 38 ± …

Stalked Crinoid Locomotion, And Its Ecological And Evolutionary Implications, Tomasz K. Baumiller, Charles G. Messing

Marine & Environmental Sciences Faculty Articles

In the past two decades, much direct evidence has been gathered on active crawling by stalked crinoids, a group generally thought to be sessile. Detailed descriptions of crawling mechanics of isocrinids in aquaria revealed only exceedingly slow movements (~0.1 mm sec^-1). Crawling at such speeds severely restricted the range of roles that this behavior could play in stalked crinoid biology and, consequently, in its potential impact on their ecology and evolutionary history. Here, we provide evidence collected in situ by submersible near Grand Bahama Island at a depth of 420 m for a different mode of crawling in …