Presentations and posters

Evolutionarily Convergent yet Behaviorally Divergent; Cross-Continental Predator-Prey Exposure Sonny S. Bleicher, Burt Kotler and Joel Brown Can populations tell the difference between foes? • Experimental series aimed at learning how individuals composing a population view two species of vipers: • • • Can they tell them apart? Do they fear the evolutionarily known predator more than a novel predator. Does a two month exposure change their perspective on both predators? Merging Behavioral Test Systems with Ecologically Relevant (yet noisy) Systems • Ecological field experiments regularly have high noise to content ratios • Traditional behavioral test systems isolate testable traits but marginalize the ecological and evolutionary context The test subject can tell their story if we let them Optimal Patch Use (Brown, 1988) • A forager balances the benefits of food gain with the costs of extracting the food from the patch and the risk of predation within the constraints of patches in its territory. • • A Giving Up Density is the density of food remaining in a patch once the forager no longer forages in the patch. As a forager exploits a patch the density of food diminishes which results in an decrease in harvest rates. This drives the forager to visit multiple patches and not remain stationary in one. The Interview Chamber • Combining the Y-maze design with the quantitative collection ability of optimal patch use theory Convergent Evolution – Similar Environment Results in Similar Community and Similar Adaptations Negev Desert Mojave Desert The Predators Cerastes cerastes Croltalus cerastes The Large Granivores Gerbillus Pyramidum (coming fall 2013) Dipodomys Merriami The Small Granivores Gerbillus andersoni (allenbyi) Chaetodipus penicillatus Is a snake a snake? • We let each rodent (30 per population) forage in the interview chambers for • two hours. Each prong of the system contained a cage with a snake (or lack thereof for the control). • After running twice through the system the animals were placed in an arena where they experienced real predation risk from both snakes for two months. • The remaining individuals were run through the chambers again to assess what was learnt. Allenby’s Gerbil 1.5 1.4 GUDS 1.3 1.2 1.1 1 0.9 0.8 Pre Post Control Pre Post Horned Viper Pre Post Pit Viper Allenby's Gerbils Strong gerbil identity effect Allenby’s Gerbil 1.5 1.4 GUDS 1.3 1.2 1.1 1 0.9 0.8 Pre Post Control Pre Post Horned Viper Allenby's Gerbils Pre Post Pit Viper Desert Pocket Mouse 1.5 1.4 1.3 1.2 1.1 1 0.9 0.8 Pre Post Control Pre Post Horned Viper Pocket Mice Pre Post Pit Viper Desert Pocket Mouse 1.5 Trend 1.4 1.3 1.2 1.1 1 0.9 0.8 Pre Post Control Pre Post Horned Viper Pocket Mice Pre Post Pit Viper Merriam’s Kangaroo Rat 1.5 1.4 GUDs 1.3 1.2 1.1 1 0.9 0.8 Pre Post Control Pre Post Horned Viper Kangaroo Rats Pre Post Pit Viper Merriam’s Kangaroo Rat 1.5 1.4 Strong trend (two tailed Pvalue of 0.06) GUDs 1.3 1.2 1.1 1 0.9 0.8 Pre Post Control Pre Post Horned Viper Kangaroo Rats Pre Post Pit Viper 0.5 ln(Handled/ Chached) 0.4 0.3 0.2 0.1 0 -0.1 -0.2 -0.3 -0.4 -0.5 ln(Handled/ Chached) 0.5 0.3 0.1 -0.1 -0.3 -0.5 Pre Post Pre Post Pre Post 0.5 ln(Handled/ Chached) 0.4 0.3 0.2 0.1 0 -0.1 -0.2 -0.3 -0.4 -0.5 ln(Handled/ Chached) 0.5 0.3 0.1 -0.1 -0.3 -0.5 Pre Post Pre Post Pre Post 0.5 ln(Handled/ Chached) 0.4 0.3 0.2 0.1 0 -0.1 -0.2 -0.3 -0.4 -0.5 ln(Handled/ Chached) 0.5 0.3 0.1 -0.1 -0.3 -0.5 Pre Post Pre Post Pre Post 0.5 ln(Handled/ Chached) 0.4 0.3 0.2 0.1 0 -0.1 -0.2 -0.3 -0.4 -0.5 ln(Handled/ Chached) 0.5 0.3 0.1 -0.1 -0.3 -0.5 Pre Post Pre Post Pre Post Conclusions • All species were weary (foraged less in the presence) of their known predator at the first encounter. • All species foraged less in the presence of the pit viper after exposure. However… • Each species managed risk from the vipers in a different manner: • Allenby’s gerbils took a chance at first and learnt to fear the new snake. • Pocket mice avoided all snakes • Merriam’s kangaroo rats avoided the novel predator at first and foraged more in the presence of it at the end (over the control) seemingly keeping an eye on the new predator. Acknowledgments • • • • • • • Joel Brown Burt Kotler Keren Embar Cynthia Downs Omri Shai Stuart Summerfield Darren Burns Questions? Searching for a post – doctorate mentor! [email protected] 

Boldness and Aggression Make Invasive Crayfish Cameron Rathjen & Sonny S. Bleicher Problem / Question Hypotheses Empirical Results Figure 1: Percent of manuscripts that describe the main behavior of invasive crayfish as risk-taking compared to manuscripts focusing on risk avoidance 0.7 0.6 4 0.5 3.5 0.4 0.3 1. Risk-taking and aggression give advantage to invasive crayfish over native species of the invaded habitat. 2. As an invasive species the rusty crayfish will forage in risky and safe microhabitats equally. 0.2 0.1 0 3 2.5 2 1.5 1 0.5 Orconectes propinquus Project Overview Crayfish species have become one of the most prevalent invasive species in aquatic systems world wide. We aimed to evolutionarily assess what enables those species to be successful invaders both based on literature comparison and empirical experiments. Figure 3: Risk as ranked by crayfish in experiment of depth and cover. Friedman's test of variance: DF (12) X2 (4.55) P-value(0.98) Ranked Risk Assesmnet What behavioral characteristics give advantage to specific species of crayfish as invasive? Meta-Analysis Orconectes Rusticus Orconectes virilis Pacificus leniusculus 0 Deep Cover Deep Cover Risk Taking Non-Risk Taking Deep Open Deep Open Shallow Cover Shallow Cover Shallow Open Shallow Open Figure 2: Percent of manuscripts that describe the main behavior of invasive species as aggressive compared to manuscripts focusing on complacency 1 Discussion 0.9 0.8 0.7 • The rusty crayfish (Orconectes rusticus) does not distinguish between safe and risky patches. 0.6 Methods . This project incorporates two parts: A meta-analysis and an empirical experiment based on the ecology of fear. 0.5 • Important trends: 0.4 0.3 • The shallow exposed food trays were the least foraged signifying that overall there is acknowledgment of risk. 0.2 0.1 Meta-Analysis: • We searched the scientific literature for empirical experiments that tested behavioral traits that characterize invasive crayfish. • We statistically analyzed the manuscripts for statistical trends in depiction of specific characteristics. Empirical Patch-Use Experiment: • In basins within the lab we recreated a habitat with similar characteristics as would be found in a natural pond. Each experimental system contained water at a depth of 30 cm and four foraging patches. • The preferred microhabitat to forage in was shallow and covered. 0 Orconectes propinquus Orconectes Rusticus Deffensive Orconectes virilis Pacificus leniusculus Aggressive Discussion • The Meta data analysis compares traits that are described as the main behavior allowing crayfish species to be invasive. • Of the four species which are the focus of the most publications we found that 2 species are aggressive and 2 are complacent. • The patch treatments were fully crossed between shallow and deep patches as well as covered and exposed (open) treatments. Each patch had 2.2 g of fresh water krill bits dispersed within pebbles. • The aggressive species O.rusticus and P.leniuculus also take risk contrary to O.virilis and O.propinquus who avoid risk. • Based on the GUDs (Giving Up Density (the amount of krill left unforged)) we ranked they fear (perceived risk) each patch posed for the crayfish • Two prevalent strategies exist to invasion: avoid conflict and risk, or take risk and act aggressive. • We analyzed the data using a Friedman’s analysis of variance for ranked data • There was no difference between deep habitat with the cover treatment. Conclusion • Orconectes rusticus showed a statistically insignificant aptitude for assessing the level of risk in a foraging area. • Orconectes rusticus showed aggressive and risk-taking behavior typical strengthening the findings of the meta-analysis regarding traits of invasiveness in crayfish. 

Biological Invaders, assessing behavioral and physiological constraint-breaking adaptations in controlled and natural settings. Sonny S. Bleicher [email protected] Biological Invasions: Strategic Evolution The evolutionary niche Resource Consumption Fitness Function (G – Function) (Vincent and Brown 2005) And to some less obvious examples How come we can have multiple species seemingly filling the same niche in one place? From G-functions to Invasions (Pintor et al. 2010)  Empty Niche From G-functions to Invasions (Pintor et al. 2010)  Empty Niche  Equal or Inferior G-Function From G-functions to Invasions (Pintor et al. 2010)  Empty Niche  Equal or Inferior G-Function  Superior Function From G-functions to Invasions (Pintor et al. 2010)  Empty Niche  Equal or Inferior G-Function  Superior Function  Incumbent Replacement (Rosenzweig and McCord 1991) How to Test Superior G-Function as Invasion Risk  Cross Continental Exposure in Common Garden Experiment How to Test Superior G-Function as Invasion Risk  Cross Continental Exposure in Common Garden Experiment Experimental Design Ecology of Fear Measuring Perception of Risk Using Foraging (Brown, 1988) �=�+ +� � Giving Up Density as a Measure of Risk in the Environment Perceived Risk GUD GUDs vary based on both actual risk (predators) and risk that effects the chance of predation in the patch: such as light (for nocturnal animals), cover and obstacles to sightlines, and distance to safety. Horned Viper New Full 3 2.5 1.5 1 0.5 0 1 2 Experimental Month Pit-Viper New Full 3 2.5 2 GUD (g) GUD (g) 2 1.5 1 0.5 0 1 2 Experimental Month Horned Viper New Full 3 2.5 1.5 1 0.5 0 1 2 Experimental Month Pit-Viper New Full 3 2.5 2 GUD (g) GUD (g) 2 1.5 1 0.5 0 1 2 Experimental Month Horned Viper New Full 3 2 1.5 1 0.5 0 1 2 Experimental Month Pit-Viper New Full 3 2.5 GUD (g) GUD (g) 2.5 2 1.5 1 0.5 0 1 2 Experimental Month Horned Viper New Full 3 2 1.5 1 0.5 0 1 2 Experimental Month Pit-Viper New Full 3 2.5 GUD (g) GUD (g) 2.5 2 1.5 1 0.5 0 1 2 Experimental Month Horned Viper New Full 3 2 1.5 1 0.5 0 1 2 Experimental Month Pit Viper New Full 3 2.5 GUD (g) GUD (g) 2.5 2 1.5 1 0.5 0 1 2 Experimental Month Horned Viper New Full 3 2 1.5 1 0.5 0 1 2 Experimental Month Pit Viper New Full 3 2.5 GUD (g) GUD (g) 2.5 2 1.5 1 0.5 0 1 2 Experimental Month 3 3 2.5 2.5 GUD (g) GUD (g) 2 1.5 2 1.5 1 1 0.5 0.5 0 C. penicillatus D. merriami D. merriami G. pymidum 3 3 2.5 2.5 GUD (g) GUD (g) 2 1.5 2 1.5 1 1 0.5 0.5 0 C. penicillatus D. merriami D. merriami G. pymidum 3 3 2.5 2.5 GUD (g) GUD (g) 2 1.5 2 1.5 1 1 0.5 0.5 0 C. penicillatus D. merriami D. merriami G. pymidum 9 8 Rodents Consumed 7 6 5 4 3 2 1 0 Cerastes cerastes Crotalus cerastes 9 8 Rodents Consumed 7 6 5 4 3 2 1 0 Cerastes cerastes Crotalus cerastes Why Kangaroo Rats and not Pocket Mice? Why Kangaroo Rats and not Pocket Mice? Why Kangaroo Rats and not Pocket Mice? Why Kangaroo Rats and not Pocket Mice? Conclusions • Sidewinder rattlesnake invasion into the old world not likely to result in successful invasion: • Heat sensing pits in this case came at a tradeoff with aggression in comparison to the robustness of the horned vipers. • Native rodents learnt rapidly (within two month) to handle the invasion with a low mortality from these predator. Conclusions • • Sidewinder rattlesnake invasion into the old world will likely not result in successful invasion: • Heat sensing pits came at a tradeoff with aggression and robustness of the horned vipers. • Native rodents learnt rapidly (within two month) to handle the invasion with a low mortality to these predator. Invasion of Kangaroo Rats to the old world deserts – RED LIGHT INVADER! • Lessening of risk via adaptation of cheek pouches and extreme bipedal agility. • Likely to result in replacement of native fauna of gerbelline species. (in light of lack of equal competitor) Conclusions • Pocket Mouse invasion to Old World – Not Likely! • Risk eversion make less likely to compete well for resources with the local aggressive gerbeline species. Conclusions • Pocket Mouse invasion to Old World – Not Likely! • • Risk eversion make less likely to compete well for resources with the local aggressive gerbeline species. Horned Viper Invasion to New World – Likely to lead to co-existence. • The horned vipers had a much higher success rate in rodent hunting than the north American species. For lack of ability to see on dark nights they make up in risk taking and aggression. Conclusions • Pocket Mouse invasion to Old World – Not Likely! • • Horned Viper Invasion to New World – Likely to lead to co-existence. • • Risk eversion make less likely to compete well for resources with the local aggressive gerbeline species. The horned vipers had a much higher success rate in rodent hunting than the north American species. For lack of ability to see on dark nights they make up in risk taking and aggression. Gerbil Invasion to New World- Not likely, but may cause changes in community. Many Thanks to my advisors, collaborators and technicians: Questions? Seeking Post –Doctoral Position [email protected] Joel S. Brown Burt P. Kotler Keren Embar Omri Shai Cynthia Downs Stuart Summerfield Darren Burns