The Hunter and the Hunted
Predator-prey interactions, like the kind between a prowling wolf and a deer, shape their surrounding ecosystems in profound ways, in particular by maintaining biodiversity. However, for smaller creatures, like arthropods, the nature of these interactions is not well understood. With these being among the most biodiverse and widespread species on Earth, researchers are very interested in finding ways to get past the existing obstacles standing in the way of directly observing these interactions.
Researchers at UC Santa Barbara, working alongside collaborators at the University of Hong Kong, Colorado State University, Stanford University and the University of Georgia, have sought to understand how the traits of these particular predators shape their interactions with other animals. In doing so, they found that the size of prey often scales with the size of predators, and that predator identity, the species of the predator in question, was more relevant in looking at the outcomes of interactions than hunting methods – like using venom or webs, for instance.
Who Brakes for Whales?
Whales are imperiled by a number of things. However, among the most lamentable and preventable causes of whale fatalities are vessel strikes, which threaten large whales like the endangered blue, humpback and fin whales. In order to combat a rash of whale fatalities, the National Oceanic and Atmospheric Administration (NOAA) has recently put in place voluntary vessel speed reduction zones off of the California coast in order to encourage the largest vessels to slow down and lower the likelihood of collisions with endangered whales.
Jono Wilson, a researcher with the Bren School of Environmental Science & Management at UCSB, working in collaboration with other researchers at the Greater Farallones Association, NOAA and The Nature Conservancy, recently sought to quantify just how effective these zones are at decreasing vessel speeds. They found that this policy led to decreased speeds but not to the degree that the whales need in order to maintain populations. In addition, in comparison with other incentive-based policies, the voluntary speed reduction zone is woefully inadequate. The researchers suggest that instating regulations might be the best bet to protect these whales.
Hot and Cold
Volcanic hotspots, like the kind which create volcanic island chains, such as Hawaii and the Galapagos Islands, are thought to come from plumes deep in the mantle which ascend to the surface — in a process known as upwelling — because they are much warmer than the surrounding mantle. However, it can be difficult to validate whether or not this is actually the case.
Matthew Jackson, a researcher in UCSB’s department of Earth Science, working with collaborators at UC Los Angeles and UC Berkeley, tried to make inferences about the temperature of these supposed hot spots by converting seismic velocity — the speed at which a wave travels through a medium — to temperature. To their surprise, they found that a large proportion of these “hotspots” are actually not hot enough to upwell. The researchers speculate that, instead, these “cold” hotspots are born in the upper mantle or “entrained and cooled by small-scale convection.”