Biological invasions threaten global economies and biodiversity

Developing nations particularly at risk

By Kat Kerlin

With the increasing pace of globalization comes the movement of invasive non-native species around the planet. Although often seen as a “first-world problem,” a new study shows these invasions threaten the economies and livelihoods of residents in some of the world’s poorest nations.

The harlequin ladybird was introduced to North America from Asia in 1916 to control aphids. It has spread to Europe and though beloved by many, is considered a pest in some regions. Credit: Wikimedia Commons

The harlequin ladybird was introduced to North America from Asia in 1916 to control aphids. It has spread to Europe and though beloved by many, is considered a pest in some regions. Credit: Wikimedia Commons

UC Davis Wildlife and Fish Ranked No. 1 in Nation

Department faculty recognized for top scholarly performance

By Kat Kerlin

Faculty in the UC Davis Department of Wildlife, Fish and Conservation Biology were recently ranked No. 1 in the nation for research productivity and impact.

Brian Todd of the UC Davis Department of Willdife, Fish and Conservation Biology found that turtles at Sequoia National Park still carry agricultural pesticides from past decades in their bodies. Credit: Brian Todd/UC Davis

Brian Todd of the UC Davis Department of Willdife, Fish and Conservation Biology found that turtles at Sequoia National Park still carry agricultural pesticides from past decades in their bodies. Credit: Brian Todd/UC Davis

The distinction came from an analysis of 33 research-extensive universities in the United States belonging to the National Association of University Fisheries and Wildlife Programs.

Do Zebra stripes confuse biting flies?

Audio: Listen to this story on our podcast, Three Minute Egghead. 

 

Zebra stripes have fascinated people for millennia, and there are a number of different theories to explain why these wild horses should be so brightly marked. A handful of laboratories around the world – including one lead by UC Davis wildlife biologist Tim Caro – have been putting these theories to the test. A new paper from Caro’s group, led by Ken Britten at the UC Davis Center for Neuroscience, puts a hole in one idea: that the stripes confuse biting flies by breaking up polarized light.

West Coast Scientists Recommend Immediate Action Plan to Combat Ocean Acidification

By Kat Kerlin

Global carbon dioxide emissions are triggering permanent changes to ocean chemistry along the West Coast. Failure to act on this fundamental change in seawater chemistry, known as ocean acidification, is expected to have devastating ecological consequences for the West Coast in the decades to come, warns a multistate panel of scientists, including two from UC Davis Bodega Marine Laboratory.

Their report, issued this week, urges immediate action and outlines a regional strategy to combat the alarming global changes underway. Inaction now will reduce options and impose higher costs later, the report said.

Not so sweet: Why Pollinators Forage on Toxic or Bitter Nectar

Audio: Listen to this story on our podcast, Three Minute Egghead. 

By Kathy Keatley Garvey

Nectar doesn’t always taste so sweet, but honeybees and other pollinators still feed on it. Now UC Davis community ecologist Rachel Vannette has discovered why pollinators continue to forage on “toxic” or bitter-tasting nectar, despite what should be a deterrent.

In newly published research in the journal Ecology, Vannette notes that floral nectar is produced by many plants to reward pollinators, but this sugary secretion often contains chemical compounds that are bitter tasting or toxic, which should deter pollinators. Plants including citrus, tobacco (Nicotiana), milkweed (Asclepias), turtlehead (Chelone), Catalpa, and others produce nectar containing bioactive or toxic compounds.

Over-evolved: Specialist jaw doomed Lake Victoria’s cichlid fish

By Betsy Towner Levine

A UC Davis Evolution and Ecology team has discovered that cichlid fishes in Africa’s Lake Victoria have suffered a unique and unexpected effect of evolutionary adaptation: mass extinction.

While a graduate student in Interim Dean Peter Wainwright’s lab, Ph.D. student Matthew McGee studied the die-off of cichlid species in Lake Victoria that occurred after Nile perch were introduced into the lake in the 1950s.

Since then the perch, Lates niloticus, have decimated the lake’s fish-eating cichlids, once the most species-rich group of cichlids in Lake Victoria. The native fish have essentially been removed and replaced by the invader.

Does hunting explain why zebras are not domesticated?

By Kathleen Holder

Why do people ride horses but not their striped African cousins?

A few zebras have accepted a rider or pulled a cart, but zebras have never been truly domesticated — and for good reason: They can be aggressive, panicky and unpredictable, making them difficult to halter and saddle train. While smaller than horses, they have powerful legs that can carry them at speeds up to 35 mph, and with a kick, can break the jaw of a predator. Those Chuck Norris-like skills are useful when you have lions, cheetahs and hyenas chasing you down for lunch.

Cold rush: Bird diversity higher in winter than summer in Central Valley

By Kat Kerlin

During the warmer months, the air surrounding California’s rivers and streams is alive with the flapping of wings and chirping of birds. But once the buzz and breeding of spring and summer are over, these riparian areas grow quiet. Sometimes it seems as though there are hardly any birds there at all.

Not so, according to a study from the UC Davis Department of Wildlife, Fish and Conservation Biology.

The fox sparrow commonly winters in the Central Valley. A UC Davis study found bird diversity in the area is actually higher in the winter than in summer, highlighting the importance of protecting habitat for birds year-round. Credit: Andrew Engilis/UC Davis

The fox sparrow commonly winters in the Central Valley. A UC Davis study found bird diversity in the area is actually higher in the winter than in summer, highlighting the importance of protecting habitat for birds year-round. Credit: Andrew Engilis/UC Davis

Changing ocean affecting salmon biodiversity and survival

What happens at the Equator, doesn’t stay at the Equator. El Niño-associated changes in the ocean may be putting the biodiversity of two Northern Pacific salmon species risk, according to a UC Davis study.

Researchers tracked the survival of Chinook and coho salmon from hatcheries in North America between 1980 and 2006.

Before the 1990s, ocean survival rates of Chinook and coho salmon varied separately from each other. However, the researchers were surprised to find that survival rates of the two species have since become increasingly similar.

Parenting style affects young voles’ brains

“Nature versus Nurture” is an old debate. How much behavior do you inherit from your parents, and how much from the environment where you grow up? A new study from the University of California, Davis shows that the amount of parental care a prairie vole gives its offspring affects the youngster’s brain structure and connectivity – probably working by changing levels of gene expression. The work is published online in the Journal of Comparative Neurology and will appear in print in a forthcoming special issue of the journal.

The prairie vole is one of the few mammal species in which both parents care for the young. Credit: Adele Seelke

The prairie vole is one of a few mammal species in which both parents care for the young. Credit: Adele Seelke