Jonathan Pruitt

Assistant Professor

Behavioral Ecology

Jonathan Pruitt
Office: (412) 624-7222
Lab: (412) 624-7269
213 Clapp Hall
4249 Fifth Avenue
Pittsburgh, PA 15260

Dr. Pruitt received his Ph.D. in 2010 with Susan Riechert at the University of Tennessee, Knoxville, performed his postdoctoral studies with Andy Sih and Jay Stachowicz at the University of California, Davis, and joined the department in 2011.

General Interests

I am interested in the causes and consequences of intraspecific trait variation. In general, evolution by natural selection is characterized as an optimizing agent, which tends to eliminate all but the most “fit” of trait variants. However, even a cursory glance of any trait type (e.g., morphology, behavior) will reveal a tremendous diversity in the kinds of strategies employed by organisms, even within a single population. I am interested in how this variation is maintained, and how it influences interspecific interactions. I use a suite of invertebrates, particularly social spiders, as models for my investigations.

How does behavioral variation influence individual- and group-performance?

 Multi-female A. studiosus colonyMulti-female A. studiosus colonyIn virtually all animal societies, group members differ along any number of trait axes. I am interested in how within-group trait variation impacts group performance. In social spiders of genus Anelosimus (Figure 1), group members exhibit variation in both their behavioral tendencies and body size, and there is growing evidence to suggest these differences shape division of labor and colony demographics. For instance, aggressive females are more likely to attack and subdue prey for their colony, while docile females tend to remain in the central portion of the colony and rear broods. In ongoing work, I am testing how the mix of types within colonies influences their survival and reproductive success in different habitats.


How do behavioral variants influence species interactions?

Agryodes elevatus (pictured) is a common web associate within A. studiosus coloniesAgryodes elevatus (pictured) is a common web associate within A. studiosus coloniesAlthough ecological studies commonly emphasize the importance of species’ functional roles (e.g., guilds), few studies consider the effects of functional diversity occurring at the level of the individual. I am interested in how the traits of individuals shape their interactions with heterospecifics. For example, whether a given heterospecific is a predator, competitor, or prey likely depends on the focal individual's body size. Or alternatively, whether two species improve or impede each other's performance might depend on whether individuals behave aggressively. In the temperate social spider Anelosimus studiosus, the mixture of behavioral tendencies within colonies changes many species interactions from parasitisms to mutualisms, and can even affect the nature of indirect species interactions (i.e., those not includng A. studiosus itself). Such trait-dependent interactions are of general interest because they create non-intuitive eco-evolutionary dynamics between population and community ecology.


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Recent Publications
  • Pruitt JN, Goodnight CJ (in review) Group selection versus group adaptation. Nature.

  • Modlmeier, Keiser CN, Wright CM, Lichtenstein JL, Pruitt JN (in review) Integrating animal personality into insect population ecology. Current Opinions in Insect Science.

  • Riechert SE, Pruitt JN, Bosco JM† (in review) In the spider nursery: indifference, cooperation, or antagonism? Animal Behaviour

  • Johnson WC, Ordway AJ, Watada M, Pruitt JN, William TM, Rebeiz M (in review) Genetic changes to a transcriptional silencer element confers phenotypic diversity within and between Drosophila species. PLoS Genetics.

  • Wright CM†, Hyland TD*, Izzo AS, McDermott DR*, Tibbetts EA, Pruitt JN (in review) Higher queen aggressiveness mitigates brood parasitism in a paper wasp. Behavioral Ecology

  • Keiser CN†, DeMarco AE*, Shearer TA*, Robertson J, Pruitt JN (in review) Putative microbial defenses in a social spider:  immune variation and antibacterial properties of colony silk. Journal of Invertebrate Pathology.

  • Modlmeier AP, Laskowski KL, Brittingham HA*, Coleman A*,  Knutson KA*,  Kuo C*, McGuirk M*, Zhao K*, Keiser CN†, Pruitt JN (in review) Group size mediates the catalytic effects of adults on juvenile collective behavior in social spiders. Proceedings of the Royal Society B

  • Wright CM†, Keiser CN†, Pruitt JN (in review) Personality and morphology predict task participation and collective foraging in the field.  Behavioral Ecology.

  • Royaute R, Pruitt JN (in review) Varying predator personalities generates contrasting prey communities in an agroecosystem. Ecology.

  • Keiser CN†, Slyder JB†, Carson WP, Pruitt JN (in review) Individual differences in predators but not producers mediate the magnitude of a trophic cascade. Ecological Entomology

  • Keiser CN†, Wright CM†, Pruitt JN (in review) Warring arthropod societies: Colony apparency and group size jointly dictate the survivorship of social spiders in a predator-dense habitat. Behavioral Ecology.

  • Pruitt JN, Modlmeier AP (in revision) Succession on a silken reef: behavior of a foundation species drives community divergence, convergence, and collapse. Ecology.

  • Chips M†, Yerger EH, Hervanek A, Nuttle T, Royo RR, Pruitt JN, McGylnn TP, Riggall CL, Carson WP (in revision) The direct impact of long-term overbrowsing on arthropods in the Allegheny National Forest region of Pennsylvania.  The Northeastern Naturalist.

  • Bengston S†, Pruitt JN, Riechert SE (2014) Environmental enrichment influences individual behavioral tendency and the structure of a behavior syndrome. Animal Behaviour 93:105-110.

  • Keiser CN†, Wright CW†, Singh N, DeShane JD, Modlmeier AP, Pruitt JN Cross-fostering by foreign conspecific queens and slavemaking workers influences individual and colony-level personality (2015). Behavioral Ecology & Sociobiology

  • Keiser CN†, Pruitt JN (2014) Personality composition is more important than group size in determining collective foraging behavior in the wild. Proceedings of the Royal Society B 281: 20141424

  • Modlmeier AP, Forrester N†, Pruitt JN (2014) Habitat structure helps guide the emergence of colony level personality in social spiders. Behavioral Ecology and Sociobiology.

  • Modlmeier AP, Laskowski K, DeMarco AE*, Coleman A*, Zhou K*, Brittingham H*, DeShane J*, McDermott D*, Pruitt JN (2014) Persistent social interactions beget more pronounced personalities in a desert dwelling social spider. Biology Letters 10: 20140419

  • Modlmeier AP, Keiser CN†, Shearer T*, Pruitt JN (2014) Species-specific influence of group composition In collective behaviors in ants. Behavioral Ecology and Sociobiology.

  • Pruitt JN, Goodnight CJ (2014) Site-specific group selection drives locally adapted group compositions. Nature 514: 359-362

  • Holbrook CT, Wright CM†, Pruitt JN (2014) Individual differences in personality and behavioural plasticity facilitates division of labor in social spider colonies. Animal Behaviour 97: 177-183


  • Keiser CN†, Pruitt JN (2014) Submersion tolerance in a lakeshore population of Pardosa lepidicina (Araneae, Lycosidae). Journal of Arachnology 42: 192-194

  • Wright CM†, Holbrook CT, Pruitt JN (2014) Animal personality aligns task specialization and task efficiency in a spider society. Proceedings of the National Academy of Sciences 111: 9533–9537.

  • Pruitt JN (2014) Animal Personality: ecology, behavior, and evolution. Current Zoology

  • Shearer TA, Pruitt JN (2014) Individual differences in boldness are positively correlated with heart rate in the orb-weaving spider, Larinioides cornutusCurrent Zoology

  • Laskowski K, Pruitt JN (2014) Evidence of social niche construction: persistent and repeatable social interactions generate stronger personalities in a social spider. Proceedings of the Royal Society of London B. 281: 20133166

  •  Pruitt JN, Berning AW, Cusack B, Shearer T, McGuirk M, Coleman A, Eng RYY, Sweeney K, Singh N (2014) Precopulatory sexual cannibalism causes increased hatching success and increases female attractiveness to males. Ethology  119: 807-810

  • Keiser CN†, Modlmeier AP, Singh N*, Jones DK†, Pruitt JN (2014) Exploring how a shift in the Physical environment shapes individual and group behavior across two social contexts. Ethology 120:825-833.

  • McDermott D*, Chips M, McGuirk M*, Armagost F*, DiRienzo N, Pruitt JN (2014) Boldness is Influence by sub-lethal interactions with predators and is associated with successful harem infiltration. Behavioral Ecology and Sociobiology.68:425-435

  • Modlmeier AP, Keiser CN, Sih A, Watters J, Pruitt JN (2014) The keystone individuals concept: an ecological and evolutionary overview. Animal Behaviour89:53–62

  • Modlmeier AP, Keiser CN†, Watters JV, Sih A, Pruitt JN (2014) The keystone individuals concept: An ecological and evolutionary overview. Animal Behaviour 89:55-62.

  • Dillon JA, Pruitt JN (2014) Use of locomotor performance capacities reflects the risk associated with specific cue types in two cursorial spider species. Journal of Arachnology.

  • Keiser CN, Pruitt JN (2013) The aggressiveness of host spiders and their inquilines jointly determine the bidirectional fitness consequences of their interactions. Behavioral Ecology25 (1):142-151

  • Pruitt JN, Keiser CN (2013) The aggressive spillover hypothesis: existing ailments and potential remedies. Ethology. 119:807–810

  • Grinsted L, Pruitt JN, Settepani V, Bilde T (2013) Individual personalities drive task differentiation in a social spider. Proceedings of the Royal Society of London Series B 280: 20131407

  • Pruitt JN, Grinsted L, Settepani V (2013) Linking levels of personality: personalities of average and extreme group members shape colony-level personality. Animal Behaviour 86:391-399.

  • Sweeney K*, Cusack B, Armagost F*, O’Brian T*, Kesier CN, Pruitt JN (2013) Predator and prey activity levels jointly influence the outcome of long-term foraging bouts. Behavioral Ecology 24:1205-1210.

  • DiRienzo N, Pruitt JN, Hedrick AV (2013) Combined behavioral tendencies of predator and prey mediate the outcome of their interaction. Animal Behaviour 86:317-322.

  • Pruitt JN (2013) A real-time eco-evolutionary dead-end strategy is mediated by the traits of lineage progenitors and interactions with colony invaders. Ecology Letters 16:879-886.

  • Jandt JM, Bengston S, Pinter-Wollman N, Pruitt JN, Raine NE, Dornhaus A, Sih A (2013) Behavioral syndromes and social insects: personality at multiple levels. Biological Reviews

  • Sweeney K, Gadd RDH, Hess ZL, McDermott D, MacDonald L, Cotter P, Armagost F, Chen JZ, Berning AW, DiRienzo N, Pruitt JN (2013) Testing the effects of rearing environment, selection, and developmental stage on the emergence of a behavioral syndrome. Ethology 119:436-447.

  • Demes KW, Pruitt JN, Harley CDG, Carrington E (2013) Survival of the weakest: increased frond mechanical strength in a wave-swept kelp inhibits self-pruning and increases whole-plant mortality. Functional Ecology 27:439-445.

  • DiRienzo N, Pruitt JN, Hedrick AV (2012) Juvenile exposure to acoustic sexual signals from conspecifics alters developmental trajectory and adult personality. Animal Behaviour 84:861-868.

  • Berning AW, Gadd RDH, Sweeney K, MacDonald L, Eng RYY, Hess ZL, Pruitt JN (2012) Sexual cannibalism is associated with female behavioral type, hunger state, and increased hatching success. Animal Behaviour 84:715-721.

  • Pruitt JN (2012) Behavioral traits of colony founders affect the life history of their colony. Ecology Letters 15:1026-1032.

  • Pruitt JN, Oufiero CE, Avilés L, Riechert SE (2012) Iterative evolution of increased behavioral variation characterizes the transition to sociality in spiders and proves advantageous. The American Naturalist 180:496-510.

  • Pruitt JN, Riechert SE (2012) The ecological consequences of temperament in spiders. Current Zoology 58:589-596.

  • Sih A, Cote J, Evans M, Fogarty S, Pruitt JN (2012) Ecological implications of behavioral syndromes. Ecology Letters 15:278-289.

  • Pruitt JN, Cote J, Ferrari MCO (2012) Behavioural trait variants in a habitat-forming species dictate the nature of its interactions with and among heterospecifics. Functional Ecology 26:29-36.

  • Pruitt JN, Stachowicz JJ, Sih A (2012) Behavioral types of both predator and prey jointly determine prey survival: potential implications for the maintenance of within species behavioral variation. The American Naturalist 179:217-227.

  • Pruitt JN, Burghardt GM, Riechert SE (2012) Non-conceptive sexual behavior in spiders: a form of play associated with body condition, personality type, and male intrasexual selection. Ethology 118:33-40.

  • Pruitt JN, Iturralde G, Avilés L, Riechert SE (2011) Amazonian social spiders share similar within-colony behavioral variation and behavioral syndromes. Animal Behaviour 82:1449-1455.

  • Pruitt JN, Ferrari MCO (2011) Intraspecific trait variants determine the nature of interspecific interactions in habitat forming species. Ecology 92:1902-1908.

  • Pruitt JN, Riechert SE, Harris D (2011) Reproductive consequences of male body mass and aggressiveness depend on females’ behavioral types. Behavioral Ecology and Sociobiology 65:1957-1966.

  • Pruitt JN, DiRienzo N, kralj-Fišer S, Johnson JC, Sih A (2011)  Individual- and condition-dependent effects on habitat choice and choosiness. Behavioral Ecology and Sociobiology 65:1987-1995.

  • Pruitt JN, Riechert SE (2011) Nonconceptive sexual experience diminishes individuals’ latency to mate and increases maternal investment. Animal Behaviour 81:789-794.

  • Pruitt JN, Riechert SE (2011) Within-group behavioral variation promoted biased task performance and the emergence of a defensive caste in a social spider. Behavioral Ecology and Sociobiology 65:1055–1060.

  • Pruitt JN, Riechert SE (2011) How within-group behavioural variation and task efficiency enhance fitness in a social group. Proceedings of the Royal Society of London Series B 278:1209-1215.

  • Pruitt JN, Demes KW, Dittrich-Reed D (2011) Temperature mediates correlated shifts in individual aggressiveness, activity-level, and social behavior. Ethology 117: 318-325.

  • Jones TC, Pruitt JN, Riechert SE (2010)  Reproductive success in a socially polymorphic spider: social individuals experience depressed reproductive success in isolation. Ecological Entomology 35:684-690. 

  • Pruitt JN, Krauel JJ (2010) The adaptive value of gluttony: predators mediate the fitness trade-offs of gluttonous behavior. Journal of Evolutionary Biology 23:2104-2111.

  • Pruitt JN, Riechert SE, Iturralde G, Vega M, Fitzpatrick BM, Avilés L (2010) Population differences in behaviour are explained by shared within-population trait correlations. Journal of Evolutionary Biology 23:748-756. 

  • Pruitt JN, Troupe JE* (2010) The effect of reproductive status and situation on locomotor performance and anti-predator strategies in a funnel-web spider. Journal of Zoology 281:39-45. 

  • Pruitt JN (2010) Differential selection on sprint speed and ad libitum feeding behaviour in active versus sit-and-wait foraging spiders. Functional Ecology 24:392-399. 

  • Pruitt JN, Husak JF (2010) Context-dependent running speed in funnel-web spiders from divergent populations. Functional Ecology 24:165-171.

  • Robbins TR, Pruitt JN, Straub LE*, McCoy ED, Mushinsky HR. (2010) Transgressive behavioural traits of Sceloporus hybrids confer fitness through advantage in territorial defence. Journal of Animal Ecology 79:137-147. 

  • Pruitt JN, Riechert SE (2009) Frequency dependent success of cheaters during foraging bouts might limit their spread within colonies of a socially polymorphic spider. Evolution 63: 2966-2973. 

  • Pruitt JN, Taylor J*, Troupe SE* (2009) Foraging benefits and limited niche overlap promote a mixed species association between two solitary species of spider. Behaviour 149:1153- 1170. 

  • Pruitt JN, Riechert SE (2009) Sex matters: sexually dimorphic fitness consequences of a behavioral syndrome. Animal Behaviour 78: 175-181. 

  • Pruitt JN, Riechert SE (2009) Male mating preference is associated with risk of pre-copulatory cannibalism in a socially polymorphic spider. Behavioral Ecology and Sociobiology 63:1573-1580.

  • Pruitt JN, Riechert SE, Jones TC (2008) Behavioral syndromes and their fitness consequences in a socially polymorphic spider, Anelosimus studiosusAnimal Behaviour 76: 871-879.

E-mail Lab

2014  Bergmann Memorial Research Award, BSF outstanding young researcher

2014 Noteworthy Professor, Pittscburgh Magazine's "Pittsburgh's Best Professors"

2014 Chancellor's Award for Research Excellence, Junior Category

2013 Outstanding Young Investigator Award, Animal Behavior Society