Behavioral ecology of avian social and reproductive behavior
I am interested in the biology of social behavior, particularly the interactions between the sexes. I find this subject fascinating because such interactions are a complex mixture of cooperation and conflict. Their study demands integration across multiple levels of biological organization and requires a diversity of approaches. I like the conceptual challenges of understanding the ecological causes and evolutionary consequences of social interactions. I also enjoy the insights gained by employing different techniques to answer a particular question. My program involves detailed observations of the behavior of free-living animals, use of molecular and biochemical techniques to uncover processes linked to mating interactions, experimental manipulations of key ecological and social factors, and empirical and theoretical work on the developmental and mechanistic processes producing behavior. Three major phenomena are being studied in my lab (you can learn more by going to my lab web page):
Extra-pair paternity in birds
For most of my career, I have focused on three main questions about avian reproductive behavior: (1) the tradeoff for males between the benefits of pursuing additional copulations versus the benefits of paternal care, (2) the factors influencing female behavior during attempted copulations by both the social mate and extra-pair males, and (3) the consequences of these copulations for the process of sexual selection. I have been studying these questions in red-winged blackbirds and house sparrows, with my students using either those systems or developing their own.
Development and function of plumage signals
I have also been interested in how male and female social interactions in a variety of contexts affect reproductive behavior, how signals might be involved in such interactions, and the underlying physiological, psychological, and developmental processes leading to signal production by the signaler and decision-making by the receiver. House sparrows, with their sexually dimorphic plumage, have been the focus of most of my recent work on these topics.
Personality, plasticity, and the nature of phenotypic variation
I have recently begun an array of studies investigating the interplay between personality and plasticity, which are elements to a broader understanding of the hierarchical nature of phenotypic variation. Behavior is particularly fascinating because it can vary among species, among populations within species, among individuals, and within individuals. Within-individual variation can be due to phenotypic plasticity, but could also come from stochastic processes. There is the possibility that stochastic variation could differ between individuals or within-individuals via adpative flexibility (e.g., variance sensitivity). I am currently using parental care in house sparrows to explore the ecological causes, proximate mechanisms, and the selective forces affecting the nature of phenotypic variation.
- "Multiple aspects of plasticity in clutch size vary among populations of a globally-distributed songbird." The Journal of animal ecology (2013): Details. Full text
- "Heterozygosity predicts clutch and egg size but not plasticity in a house sparrow population with no evidence of inbreeding." Molecular ecology 21, 2 (2012): 406-20. Details. Full text
- "Evolution in response to social selection: the importance of interactive effects of traits on fitness." Evolution; international journal of organic evolution 66, 3 (2012): 890-5. Details.
- "Inclusive fitness theory and eusociality." Nature 471, 7339 (2011): E1-4; author reply E9-10. Details. Full text
- "Individual variation in parental care reaction norms: integration of personality and plasticity." The American naturalist 178, 5 (2011): 652-67. Details. Full text
- "Broad-scale latitudinal patterns of genetic diversity among native European and introduced house sparrow (Passer domesticus) populations." Molecular ecology 20, 6 (2011): 1133-43. Details. Full text
- "Sexual conflict as a partitioning of selection." Biology letters 5, 5 (2009): 675-7. Details. Full text
- "Sperm competition selects beyond relative testes size in birds." Evolution; international journal of organic evolution 63, 2 (2009): 391-402. Details.
- "Complex interactions among temporal variables affect the plasticity of clutch size in a multi-brooded bird." Ecology 90, 5 (2009): 1162-74. Details.
- "Heterozygosity and extra-pair paternity: biased tests result from the use of shared markers." Molecular ecology 18, 9 (2009): 2010-21. Details. Full text
- "No evidence of current sexual selection on sexually dimorphic traits in a bird with high variance in mating success." The American naturalist 167, 6 (2006): e171-89. Details. Full text
- "Tests of spatial and temporal factors influencing extra-pair paternity in red-winged blackbirds." Molecular ecology 14, 7 (2005): 2155-67. Details. Full text
- "Correlates of cell-mediated immunity in nestling house sparrows." Oecologia 141, 1 (2004): 17-23. Details. Full text
- "Alternative mechanisms of nonindependent mate choice." Animal behaviour 59, 3 (2000): 467-476. Details.
- "Sex and parenting: the effects of sexual conflict and parentage on parental strategies." Trends in ecology & evolution 11, 2 (1996): 87-91. Details. Full text
- "Reproductive physiology and sperm competition in birds." Trends in ecology & evolution 11, 5 (1996): 191-2. Details. Full text
- "DNA "fingerprinting" reveals high levels of inbreeding in colonies of the eusocial naked mole-rat." Proceedings of the National Academy of Sciences of the United States of America 87, 7 (1990): 2496-500. Details. Full text
- "Seasonal and sex-specific mRNA levels of key endocrine genes in adult yellow perch (Perca flavescens) from Lake Erie." Marine biotechnology (New York, N.Y.) 11, 2 (1969): 210-22. Details. Full text
- "The bird of time: cognition and the avian biological clock." Frontiers in molecular neuroscience 5, (0): 32. Details. Full text