Fear as an ecosystem engineer

This post contributed by Cristina Eisenberg, conservation biologist at Oregon State University Over the past three years I have conducted thirteen hundred focal animal observations on elk in the northern and southern Rocky Mountains. This involves patiently watching one animal at a time for up to twenty minutes and recording its wariness–that is, the amount of time it spends with its head down feeding versus head up, scanning for predators. Prey group size and a host of environmental factors can influence vigilance behavior. My research questions have to do with whether the vigilance of ungulates—such as elk, deer and other hooved animals— varies based on wolf population dynamics or other environmental factors that can influence predation risk. For example, would lone wolves passing through an area occasionally, but not denning there (as is the case with a returning wolf population in the Southern Rocky Mountains) have the same effect as several well-established packs using an area? Do terrain features such as downed wood, which may make it more difficult for an elk to escape a wolf, increase elk wariness? And could fear-based behavior vary by season, age and sex of the animals observed, herd size or human management of wolves? Termed the ecology of fear by ecologist Joel Brown, these predator-driven dynamics can have far-reaching effects on ecosystems via trophic cascades. Trophic cascades are the direct and indirect effects of an apex, or top, predator in a food web. In 1974 in the Aleutian archipelago, Jim Estes and his colleagues found that removing sea otters releases their primary prey, sea urchins, from predation. As sea urchins explode in number, they consume vegetation unsustainably, thereby reducing habitat for other species such as fish. The presence of a predator, such as the wolf, affects prey foraging behavior as prey try to balance the need to detect predators with meeting their  nutritional needs. These behavioral effects have been observed between spiders and their grasshopper prey by Oswald Schmitz and colleagues, as with sea urchins in terrestrial systems: Intensive browsing can lead to herbivores literally eating themselves out of house and home and, consequently, to a loss of biodiversity and ecosystem destabilization. Lacking apex predators to keep ungulates in check, ecosystems can support fewer species, such as birds and butterflies , because the plants that create habitats for these species have been over-browsed. Some predators and their prey naturally fluctuate in population size; this cycling can leave noticeable marks on the landscape. However, scientists are finding that these interactions are complex beyond the typical ebb and flow of predator and prey numbers. Assessing ungulates and large carnivores in the northern hemisphere, conservation biologist...

Read More

From the Community: Holiday Gift Edition

Ecological science comes in all shapes and sizes, and holiday gift-giving is no exception. If you prefer your celebrations to be infused with science, then you might enjoy these holiday gift ideas as well. Who knows, maybe friends and relatives will learn a little bit about ecology too! Games: For those of us who would like to include science in our competitive pursuits, thankfully there are plenty of options. The card game Parasites Unleashed!, for example, challenges players to behave like a nematode worm or other parasites, invading, boring and populating their way to success. In the Animals Linkology Science Card Game, players connect species with words that describe their physical characteristics, classification or behavior—such as wings, bird, predator. For active kids and adults, there are Forest Council Stewardship certified sports balls available as well. For kids: Especially for children, learning is observing first-hand and up close. To help them generate questions about habitats and animal behavior, try a colorful ant farm or a window mounting bird house. A talking microscope could be perfect for a junior entomologist. There is also Smithsonian’s EcoDome Habitat that challenges kids to maintain separate ecosystems and keep them interconnected. And Plush Food Chain Friends are pretty self-explanatory. Clothing: There are of course catchy t-shirts with phrases such as, “Taxonomy: Keeping the family in order” and “Natural Selection: Good things come to those who mate.” But thoughtful gifts such as repurposed jewelry made from typewriter keys or old cookbooks have an appealing artisan flare and reduce waste. Inside, outside: Terrariums are coming back in style as chic home accessories; these can be purchased or easily made out of empty wine bottles or old light bulbs. Also, a portable charger that generates power from kinetic energy is perfect for hiking and other outdoor activities—the more walking, the more energy is charged. Wrapping: Presents are usually not considered complete without wrapping. If the comic’s section of the newspaper is not cutting it, then there are some other creative options. Seeded wrapping paper, for example, can be planted in the spring for perennial wildflowers, and the gift could be secured with botany tape to start a conversation about the importance of natural collections. Photo Credit:...

Read More

Taking a shot at photographing science and nature

Go to Google Images and search for “science.” What are the results? More than likely, the search will come up with beakers, protons, lab coats, double helixes, pulsars, microscopes and perhaps a smattering of trees and images of the globe. Photographs of researchers boot-high in streams collecting samples, for instance, or of a Cayman Island blue iguana in its natural habitat, would probably be few and far between. But images such as these—which show an aspect of the biological sciences, environmental processes or a subject of ecological research—rarely show up, even though they are of course also science.

Read More

From the Community: giant jellyfish, wine-scented flowers and 50 ideas in ecology

A rare jellyfish is captured on video as it swims in the Gulf of Mexico, New Scientist outlines ideas in ecology that could change the world, researchers examine a wine-scented flower and its pollinators, the top 20 microscope photos of the year and putting a price on Earth. Here are the latest stories in ecology.

Read More

Putting ecology back in school

Currently, U.S. students can graduate high school without taking a course that covers ecological science or that encourages ecological literacy—the ability to understand the interconnectedness of life on Earth. By not being exposed to this material, students’ career paths can be dramatically impacted. On a basic level, they may not consider the advantages of exploring ecology as an option for post-secondary education. But sometimes, they may never understand the complex dynamics of natural and built environments, including the role of humans in an ecosystem.

Read More

From the Community: Ecology in uncommon roles

Based on news articles and studies from last week, ecology can be involved in serenading your mother, inspiring fashion, describing the fundamentals of politics and guiding robots in nano-scale terrain. Here are a few examples of ecology in uncommon roles from the second week in May.

Read More

Q&A: Ecologists assess oil spill damage

An oil slick originating from a rig about 130 miles southeast of New Orleans, which is dumping oil into the Gulf of Mexico at a rate of approximately 25,000 barrels per day, is drifting toward the Alabama, Florida and Louisiana coasts, and scientists are still assessing the ecological impact that will result. In the Q&A below, three members of the Ecological Society of America’s Rapid Response Team discuss the current and possible future damage of this spill and the effects it could have on the Gulf region.

Read More

From the Community: Giant monitor lizard, seafloor scavengers and fruit fly aerodynamics

Climate change prompts migratory birds to stay home, Simpsons’ writer talks conservation and the U.K. announces newest and largest MPA. Here’s what is happening in ecology from the second week in April.

Read More