Richard Buchholz
Associate Professor of Biology
Phone Number: (662)915-5012
Email: byrb@olemiss.edu
http://olemiss.edu/depts/biology/people/faculty/buchholz/index.php

Key Words: Mate Choice Research, Conservation Biology, Avian Research

Research Description:

My current studies of sexual selection in the Wild Turkey build on my previously published work.

The wild turkey (Meleagris gallopavo) is a highly polygynous, sexually-dimorphic species, well suited to testing the intraspecific predictions and assumptions of 'good genes' models of female choice. I (Buchholz 1995, 1996, 1997) tested alternative hypotheses for the maintenance of 'fleshy' ornamentation in males of this species. In addition to uncovering a non-sexual function for the brightly colored, bare head of the male wild turkey (which is crucial for maintaining sublethal body temperatures under warm ambient conditions and during physical exertion), my work also demonstrated that one aspect of male head ornamentation, the frontal process, or snood is subject to both intersexual and intrasexual selection. Captive female wild turkeys prefer to mate with long snooded males, and during dyadic interactions, male turkeys deferred to males with relatively longer snoods. These results were demonstrated using both live males and controlled artificial models of males.

Why should turkeys pay such close attention to the length of a male's snood? Data on the parasite burdens of free-living wild turkeys revealed a negative correlation between snood length and infection with intestinal coccidia, Eimeria spp., a deleterious protozoan parasite. That is, in the wild the long snooded males preferred by females and avoided by males seemed to be resistant to coccidia infection. I have suggested that this is a case of female choice for male 'good genes'. Females may be choosing coccidia-resistant males as mates so that their own offspring will inherit resistance genes and be more likely to survive. I hypothesized that coccidia-free males were probably more dominant than infected males. If so, selection should favor males who can assess the quality of their competitors before fighting, and thus avoid wasting energy in fights that they are likely to lose (Buchholz 1997).

The interpretations of the adaptive significance of the turkey's snood hinge strongly on the negative correlation between snood length and coccidia load obtained from the field captures. However, the causal relationship between parasite burden and snood length (or mate choice) have not yet been demonstrated, nor has the mechanism by which these parasites limit ornament growth been shown. These factors would need to be demonstrated clearly in order to understand the results of earlier studies showing female preference for male ornamentation in turkeys.

My current projects involve a series of surveys and controlled experiments for elucidating these questions:

1. What is the genetic basis for helminth (tapeworm and nematode) resistance in free living wild turkeys, and the heritability of resistance to coccidia infection in captive birds? (in collaboration with Ann Findley, Steve Hecht, Mary Jones)
2. What is the impact of coccidia infection on the immunocompetence, endocrinology, general condition, mating success and dominance interactions of captive wild turkeys? (in collaboration with Rebecca Holberton)
3. What are the competitive interactions among the seven species of turkey coccidia, and can these species be identified by PCR?

Honors Theses:

Fry, Bennett (2021) Association of TRIM Gene Variation and LPDV Infection Patterns in Wild Turkeys (full text)

Cox, Keely Ann (2020) An Investigation of the Practical Challenges to Using Molecular Genetic Techniques to Identify the Parasite Burdens of Vertebrate Animals from Non-Invasive Sampling (full text)

Hyche, Walker (2019) An Investigation of Possible Reservoirs of Lymphoproliferative Disease Virus of Turkeys in Mississippi (full text)

Benton, Louis Wilson (2018) Effects of Housing Management on Vaccination Success Against Eimeria Infection in Chickens (full text)

Ku, Tobi (2017) Investigating veterinary management choices for canine heartworm disease (Dirofilaria immitis) in northern Mississippi. (full text)

Abunemeh, Mariam (2016) Methods of Quantification and Characterization of Coccidian Oocysts. (full text)

Vernier, Mara E. (2016) Courtship lateralization and its effect on mating success of male wild turkeys (Meleagris gallopavo). (full text)

Smith, Megan L. (2015) Understanding the implications of climate change for birds of the family Phasianidae: incorporating fleshy structures into models of heat dissipation capacity. (full text)

Grey, Callie (2014) Understanding the Karoo: Investigating the Function of a Copulation Call in Female Wild Turkeys Meleagris gallopavo. (full text)

Youngblood, Wesley (2014) Parasitism and feather reflectance in mourning doves (Zenaida macroura). (full text)

Debardeleben, Miles (2012) "An Investigation of Host Variation In the Host-Parasite Interaction of Sciurus carolinensis and Cuterebra emasculator"

Orr, Joseph Griffin (2010) "Investigating the effects of antioxidant vitamins on the immunocompetence of domestic turkeys (Meleagris gallopavo) infected with coccidian parasites"

Harrison, Virginia Austin (2007) "Growth and Immunocomptence in Parasitized Domestic Turkeys( Meleagris gallapavo): Is There a Trade-off?

Jackson, Laura Kathryn (2007) "Parasite Resistance and Heterozygosity of Broad Breasted White Turkeys"

LeBlanc, Dustin Paul (2005) “Investigating the Value of Circadian Rhythmicity to Identify Different Species of Turkey Coccidia in the Genus Eimeria”

Boone, William Wilson (2003) "Spleen RNA Concentration and Male Oramentation in the Wild Turkey" (full text)