Ann Hedrick

image of Ann Hedrick

Adjunct Professor


Neurobiology, Physiology and Behavior

Offices and Labs

1011 Life Sciences
(530) 754-7611

Profile Introduction

Animal personalities; mate choice and sexual selection; antipredator behavior; genetic basis for individual differences in behavior; correlations among functionally different behavioral traits.


1987 PhD (Zoology) University of California, Davis
1984 MS (Zoology) University of California, Davis
1977 BA (Biology) University of Virginia

Research Interests

My research program focuses on the evolution of behavior, particularly the evolution of animal personalities, mating behavior, and antipredator behavior. I am especially interested in the interplay between sexual selection and natural selection. My research falls into three general areas of inquiry: (1) Animal personality and measuring correlations between different behavioral traits; (2) Studies of individual variation in mating preferences, (3) Investigating links between mating behavior and anti-predator behavior. For this work, I am using the field cricket, Gryllus integer. In this species, males call to attract females using a rapid trill, and females generally prefer males with longer durations of uninterrupted trilling to those with shorter durations. Call duration is a heritable trait. I am now investigating correlations among functionally different behavioral traits ("behavioral syndromes") and the genetic basis for these correlations, causes for differences in mating selectivity among females, and mating behavior and anti-predator behavior in populations that differ in predation. My work has been supported by grants from the National Science Foundation and the Academy of Finland.

Animal personality; correlations among functionally different traits; genetic basis for individual differences in behavior; mate choice and sexual selection; antipredator behavior.

Department and Center Affiliations

Neurobiology, Physiology & Behavior


Animal Behavior Society
International Society for Behavioral Ecology

CBS Grad Group Affiliations

Animal Behavior

Specialties / Focus

Animal Behavior
  • Behavior Ecology and Sociobiology


Hedrick Laboratory
  • Ann Hedrick, P.I., Kenneth Chapin (Postdoctoral Scholar), Cameron Jones, Tinh Ton

Field Sites

California, Arizona

Teaching Interests

Animal behavior.


NPB 90C Current Topics in Animal Behavior
NPB 159 Frontiers in Animal Behavior


5/5/2017 10:16:42 AM
  • Hedrick, A. (Editor) 2017. The development of animal personality. e-book, Frontiers in Ecology and Evolution, doi:10.3389/fevo.2017.00014

  • DiRienzo, N. & A. Hedrick. 2014. Animal personalities and their implications for complex signaling. Current Zoology 60: 381-386.

  • Hedrick, A.V. & J. Bunting. 2013. An attractive male trait and aggressiveness are negatively correlated in wild field crickets, but uncorrelated in lab-reared crickets. Behavioral Ecology and Sociobiology 68: 233-238.

  • Hedrick, A. 2013. Family effects on anti-predator behavior in the field cricket Gryllus integer. Journal of Insect Behavior 26: 832-836.

  • Polkii, M., Kortet, R., Hedrick, A. & Rantala, M. 2013. Dominance is not always an honest signal of quality but females may be able to detect the dishonesty. Biology Letters 9: 20121002.

  • DiRienzo, N., Pruitt, J., & A.V. Hedrick Juvenile exposure to acoustic signals from conspecifics alters developmental trajectory and adult personality. Animal Behaviour 84: 861-868.

  • Hedrick, A.V. & R. Kortet. 2012. Effects of body size on selectivity for mating cues in different sensory modalities. Biological Journal of the Linnean Society 105: 160-168.

  • Hedrick, A. & R.K. Kortet. 2012. Sex differences in the repeatability of boldness over metamorphosis. Behavioral Ecology and Sociobiology 66: 407-412.
  • Hedrick, A. & R. Kortet. 2012. Effects of body size on selectivity for mating cues in different sensory modalities. Biological Journal of the Linnean Society 105:160-168.
  • Niemela P., DiRienzo N., & Hedrick, A. 2012. Predator-induced changes in the boldness of naive field crickets, Gryllus integer, depends on behavioural type. Animal Behavior 84, 129-135.

  • Niemela,P., Vainikka A., Hedrick, A. & Kortet R. 2011. Integrating behaviour with life history: boldness of the field cricket, Gryllus integer, during ontogeny. Functional Ecology 26: 450-456.

  • Kortet, R., Hedrick A.V. & Vainikka, A. 2010. Parasitism, predation and the evolution of animal personalities. Ecology Letters 13: 1449-1458.
  • Leonard, A.S. & A.V. Hedrick. 2010. Long-distance signals influence assessment of close range mating displays in the field cricket, Gryllus integer. Biological Journal of the Linnean Society 100: 856-865.
  • Leonard, A.S. & A.V. Hedrick. 2009. Single versus multiple cues in mate discrimination by males and females. Animal Behaviour 77: 151-159.
  • Leonard, A.S. & A.V. Hedrick. 2009. Male and female crickets use different decision rules in response to mating signals. Behavioral Ecology 20: 1175-1184.
  • Kortet, R. & A. Hedrick. 2007. A behavioural syndrome in the field cricket Gryllus integer: intrasexual aggression is correlated with activity in a novel environment. Biological Journal of the Linnean Society 91: 475-482.
  • Kortet, R.K. & A.V. Hedrick. 2004. Detection of the spider predator, Hololena nedra by naive juvenile field crickets using indirect cues. Behaviour 141: 1189-1196.
  • Kortet, R., M.J. Rantala & A. Hedrick. 2007. Boldness in anti-predator behavior and immune defense in field crickets. Evolutionary Ecology Research 9: 185-197.
  • Hedrick, A.V., M. Hisada & B. Mulloney. 2007. Tama-kugel: Hardware and software for measuring direction, distance and velocity of locomotion by insects. Journal of Neuroscience Methods 164: 86-92.
  • Kortet, R.K. & A.V. Hedrick. 2005. The scent of dominance: female field crickets use odor to predict the outcome of male competition. Behavioral Ecology & Sociobiology 59: 77-83.
  • Hedrick, A.V. & R.K. Kortet. 2006. Hiding behaviour in two cricket populations that differ in predation pressure. Animal Behaviour 72: 1111-1118.
  • Hedrick, A.V. 2005. Environmental condition-dependent effects on a heritable, preferred male trait in the field cricket, Gryllus integer. Animal Behaviour 70:1121-1124.
  • Hedrick, A.V. & B. Mulloney. 2004. A multichannel electronic monitor of acoustic behaviors, and software to parse individual channels. Journal of Neuroscience Methods 133: 201-210.
  • Hedrick, A.V., D. Perez, N. Lichti & J. Yew. 2002. Temperature preferences of male field crickets (Gryllus integer) alter their mating calls. Journal of Comparative Physiology A 188: 799-805.
  • Hedrick, AV. 2000. Crickets with extravagant mating songs compensate for predation risk with extra caution. Proceedings, Royal Society of London B. 267:671-675
  • Dill LM, Hedrick AV and A Fraser. 1999. Male mating strategies under predation risk: do females call the shots?. Behavioural Ecology. 10:452-461
  • Hedrick, A.V. and T. Weber. 1998. Variance in female responses to the fine structure of male song in the field cricket, Gryllus integer. Behavioral Ecology. 9:582-591
  • Hedrick, A.V. 1994. The heritability of mate-attractive traits: a case study on field crickets. pp. 228-250 in C. Boake, ed. Quantitative genetic studies of behavioral evolution. University of Chicago Press.
  • Hedrick A.V. & L.M. Dill. 1993. Mate choice by female crickets is influenced by predation risk. Animal Behaviour 46: 193-196.
  • Riechert, S.E. & A. V. Hedrick 1993. A test for correlations among fitness-linked behavioural traits in the spider Agelenopsis aperta (Aranae, Agelenidae). Animal Behaviour 46: 669-675.
  • Riechert S.E. & A. V. Hedrick. 1990. Levels of predation and genetically based anti-predator behaviour in the spider, Agelenopsis aperta. Animal Behaviour 40: 679-687.
  • Hedrick, A.V. & S.E. Riechert. 1989. Genetically-based differences between populations in the foraging behavior of a spider. Oecologia 80: 533-539.
  • Hedrick A.V. & E.J. Temeles. 1989. The evolution of sexual dimorphism in animals: hypotheses and tests. Trends in Ecology and Evolution 4: 136-138.
  • Hedrick, A.V. 1988. Female choice and the heritability of attractive male traits: an empirical study. American Naturalist 132: 267-276.
  • Hedrick, A.V. 1986. Female preferences for male calling bout duration in a field cricket. Behavioral Ecology and Sociobiology 19: 73-77.