April 19, 2011 | Courtesy of The Daily Mississippian
Richard Buchholz, associate professor and biologist at the University of Mississippi, has discovered that female wild turkeys choose their mates based on physical appearances.
“Turkeys are heavily ornamented, and I was interested in understanding how such strange structures could evolve,” Buchholz said. “Most birds are drab in coloration, but turkeys have those bright bare heads, glossy feathers and weird beard and spurs. They seemed like a perfect model species to answer my scientific question.”
Buchholz is studying sexual selection in wild turkeys, or why the female turkeys chose certain males as mates.
“I create different treatment groups of female turkeys in this project,” Buchholz said. “I want to know if females that were susceptible to parasites when they were young chicks choose different types of males than females that were kept disease-free with medication.”
The research is conducted at the University of Mississippi Field Station, located 11 miles from campus.
At the field station, male turkeys are kept in separate cages in a row. When the female turkey is released into a pathway by the males’ cages, she will chose her mate and lie in front of his cage.
“Males must display to be chosen, but females don’t like males who display too forcefully or are aggressive to them,” Buchholz said. “The head ornaments play a role in female choice, but females have individual preferences. The most repeatable finding is that females like males with longer snoods (the distensible frontal process that dangles from their forehead during display). We also know that snood length correlates with specific genes at the immune genes that tie into disease resistance. Thus females are usually finding mates that have good genes for parasite resistance.”
The original turkeys were purchased as day-old chicks from game farms around the United States. Those turkeys were then bred to make the birds that are currently at the field station.
They also use chicks hatched from eggs collected from wild nests around the field station.
“We collect data by handling and measuring the birds, examining the DNA sequences from blood samples and the behavioral trials in which females are given choices of males,” Buchholz said.
The results of the research can help uncover more about sexual selection in wildlife.
“The research results can be used by wildlife biologists for management of turkey populations,” said Wendy Garrison, adjunct instructor in biology. “They can also be used as a scientific basis to test other hypotheses about game species, endangered species or domesticated species to name a few. Finally, the research is interesting just for its own sake, and it adds to the body of knowledge about our world.”
The National Science Foundation awarded Buchholz a $290,000 grant to conduct research.
The grant ended in 2010, but Buchholz is still doing research on the wild turkeys.
“It is hard to test a hypothesis, have an adequate sized experiment and control for all the possible variables,” Garrison said. “Dr. Buchholz, his students and the field station staff have put in the work to have a sound scientific experiment. The fact that the University Field Station has the space to set up research of this kind is a plus for scientists and students alike.”
From the DM by Kristie Warino