Graduate student Kristine Preston wins competition for A. Brazier Howell Award

The title of Preston's talk was "Testing the relative importance of predator and food-mediated processes controlling fecundity in an arid shrubland songbird." To win the award, Preston had to give a 12-minute long talk and answer questions from the audience on her research. Only one person receives the award each year by the Cooper Ornithological Society. This year, 40 students competed for the award.

"I am very honored to receive the A. Brazier Howell Award," said Preston. "It is a wonderful feeling to know that professionals in my field considered my work worthy of the award. I consider this an important professional achievement. Receiving this award reflects how much I have benefited from the support and advice of my advisor, Dr. John Rotenberry, and from my dissertation committee, my fellow lab members, and my family."

Each year, the A. Brazier Howell Award honors the best student paper presented at the Cooper Ornithological Society annual meeting. The awardee must be a student or have received his/her degree since the last annual meeting and must be the sole author or senior author of the paper. Preston is the sole author of her award-winning paper.

The Cooper Ornithological Society was organized in 1893 and incorporated in 1934. Today the Society numbers over 3000 international professional and amateur ornithologists, and is the second-largest such society in the world. The purpose of the organization is to advance our knowledge of birds and their habitat.

For her Ph. D. dissertation, Preston is investigating how individuals respond to different selective agents in their environment and whether behavioral responses influence individual fitness.

"Kris has put in an astounding amount of effort collecting data on wrentits in the field for the last three years," said John T. Rotenberry, professor of biology at UC Riverside and Preston's research advisor. "That effort has really started to pay off, beginning with the results of this particular experiment." Rotenberry explained that ecologists have been arguing about the dominance of 'top-down' vs. 'bottom-up,' that is, predators vs. food control of populations for years, but this is the first experiment to manipulate both simultaneously. "Given the contentious nature of these arguments, it's probably not surprising that Kris clearly showed that both worked independently and additively to influence fecundity in these birds," he said.

Besides the A. Brazier Howell Award, Preston has won a Graduate Assistance in Areas of National Need (GAANN) award from the UCR Department of Biology (1999-2001), a Dissertation Research Grant from the Graduate Division at UC Riverside (1999), an Association of Field Ornithologists Travel Award (1998), and a Newell Award from the UCR Department of Biology (1997).

She graduated from UC Davis in 1988 with a B.S. degree in wildlife and fisheries biology.

Summary of Preston's paper that won the A. Brazier Howell Award:

The importance of food and predator-mediated processes in determining fecundity in birds has long been debated. Determining the relative importance of these two selective agents can provide greater insight into the evolution of avian life history strategies and a better understanding of population dynamics. I investigated the effects of these two factors on the fecundity of an arid shrubland songbird, the Wrentit (Chamaea fasciata). I simultaneously manipulated food availability and nest predation levels (through food supplementation of Wrentit pairs and their primary nest predator, the Western Scrub-Jay (Aphelocoma californica)). Both food limitation and nest predation had equally adverse and independent effects on Wrentit fecundity.

Together these two factors accounted for almost all variation in reproductive success. Successful Wrentit reproduction at the study site appears to be linked to the nesting phenology and food requirements of the Western Scrub-Jay.

Persistent renesting by Wrentit pairs is made possible with adequate food late into the breeding season, which allows Wrentits to escape the window of nest predation and successfully reproduce.

The UC Riverside Department of Biology serves three main functions: undergraduate instruction, graduate education, and research in basic biology. The department conducts research and teaching in many areas of life science including cell biology, conservation biology, developmental biology, ecology, evolution, molecular biology, physiology, and population biology. The department is part of the College of Natural and Agricultural Sciences, a multi-departmental unit dedicated to instruction and basic research in the physical and life sciences, and also to 'mission-oriented' applied research in the agricultural sciences. The Biology major is a popular undergraduate major on the UC Riverside campus, with approximately 1000 students currently enrolled. Biology also provides much of the undergraduate instruction for majors in other life science departments and other science majors.

The University of California, Riverside offers undergraduate and graduate education to nearly 16,000 students and has a projected enrollment of 21,000 students by 2010. It is the fastest growing and most ethnically diverse campus of the preeminent ten-campus University of California system, the largest public research university system in the world. The picturesque 1,200-acre campus is located at the foot of the Box Springs Mountains near downtown Riverside in Southern California. More information about UC Riverside is available at http://www.ucr.edu or by calling 909-787-5185. For a listing of faculty experts on a variety of topics, please visit http://mmr.ucr.edu/experts/.