4 million years at Africa's salad bar

As grasses grew more common in Africa, most major mammal groups tried grazing on them at times during the past 4 million years, but some of the animals went extinct or switched back to browsing on trees and shrubs, according to a study led by the University of Utah.

El Niños and Bunny Booms

At times during the past 10,000 years, cottontails and hares reproduced like rabbits and their numbers surged when the El Niño weather pattern drenched the Pacific Coast with rain, according to a University of Utah analysis of 3,463 bunny bones. The study of ancient rabbit populations at a Baja California site may help scientists better understand how mammals that range from the coast to the interior will respond to climate change, says anthropology doctoral student Isaac Hart. He is first author of the study to be published in the July issue of the journal Quaternary Research.

Bird populations responding to climate change

With puzzling variability, vast numbers of birds from Canada’s boreal forests migrate hundreds or thousands of miles south from their usual winter range. These so-called irruptions were first noticed by birdwatchers decades ago, but the driving factors have never been fully explained. Now scientists have pinpointed the climate pattern that likely sets the stage for irruptions – a discovery that could make it possible to predict the events more than a year in advance.The researchers found that persistent shifts in rainfall and temperature drive boom-and-bust cycles in forest seed production, which in turn drive the mass migrations of pine siskins, the most widespread and visible of the irruptive migrants. “It’s a chain reaction from climate to seeds to birds,” says atmospheric scientist Court Strong, an assistant professor at the University of Utah and lead author of the study.

Light rail-based air quality monitoring study launched in Salt Lake City

A team of University of Utah researchers has launched an air pollution monitoring project that will result in a better understanding of air quality across the Wasatch Front.Utah researchers Logan Mitchell, Erik Crosman, John Horel, and John Lin of the University of Utah’s Department of Atmospheric Sciences are a few months in to the ongoing project, in which data are being gathered from sensors mounted on TRAX trains, in coordination with several partners in the community.The project seeks to measure pollutants, including fine particulate matter (PM2.5) ozone and greenhouse gases, as well as meteorology using instruments installed on the Utah Transit Authority’s light rail train (TRAX) that travels through the Salt Lake Valley. 

Paleocene-Eocene thermal maximum had similarities to current warming

The rate at which carbon emissions warmed Earth’s climate almost 56 million years ago resembles modern, human-caused global warming much more than previously believed, but involved two pulses of carbon to the atmosphere, University of Utah researchers and their colleagues found.The findings mean the so-called Paleocene-Eocene thermal maximum, or PETM, can provide clues to the future of modern climate change. The good news: Earth and most species survived. The bad news: It took millennia to recover from the episode, when temperatures rose by 5 to 8 degrees Celsius (9 to 15 degrees Fahrenheit).

Co-evolution Benefits Aborigines and Kangaroos

Australia's Aboriginal Martu people hunt kangaroos and set small grass fires to catch lizards, as they have for at least 2,000 years. A University of Utah researcher found such man-made disruption boosts kangaroo populations – showing how co-evolution helped marsupials and made Aborigines into unintentional conservationists. "We have uncovered a framework that allows us to predict when human subsistence practices might be detrimental to the environment and when they might be beneficial," says Brian Codding, an assistant professor of anthropology.