Inter-sexual social interactions in Cebus capucinus

Advisors: Leila M. Porter.Committee members: Mitchell T. Irwin; Katherine C. MacKinnon.Includes bibliographical references.Includes illustrations.Researchers examine an animal's behaviors in order to determine how they enhance the animal's fitness. However, animals often exhibit behaviors that expend energy, but do little to improve its proximate survival or reproductive success. These behaviors may represent long-term strategies and are therefore more difficult to document than behaviors that provide immediate benefits. I observed white-faced capuchin social behavior in Costa Rica with the goal of identifying inter-sexual social behaviors that are intentional, regular, and serve no immediate reproductive or survival advantage. For example, interactions with males and non-cycling females provide no immediate reproductive benefits I observed interaction patterns between 11 adults in one social group of C. capucinus during 55.5 hours of observation, contrasting interaction patterns among the alpha male, subordinate males, cycling females, and non-cycling females. Both cycling and non-cycling females interacted significantly more times, but for a shorter duration, with the alpha male than subordinate males. Non-cycling females and subordinate males spent the most time in social interaction (46% of heterosexual social behavior). These data suggest that while both cycling and non-cycling females preferred to associate with the alpha male, inaccessibility or lack of alpha interest may have limited their ability to do so. All adults except the alpha male associated with other group mates in a non-random pattern, suggesting there are benefits of inter-sexual interaction beyond immediate survival or reproduction. There were also unusually high frequencies of same sex social interaction, which may be a reaction to environmental stress as there was anthropogenic disturbance in their home range during the study. Longer studies of this group and of other groups can help to clarify the long-term benefits of inter-sexual social interaction.M.A. (Master of Arts

Custom mentholation of commercial cigarettes for research purposes

In the U.S. menthol remains the sole permitted characterizing cigarette flavor additive in part because efforts to link menthol cigarette use to increased tobacco-related disease risk have been inconclusive. To perform definitive studies, cigarettes that differ only in menthol content are required, yet these are not commercially available. We prepared research cigarettes differing only in menthol content by deposition of l-menthol vapor directly onto commercial nonmenthol cigarettes, and developed a method to measure a cigarette's menthol and nicotine content. With our custom-mentholation technique we achieved the desired moderately high menthol content (as compared to commercial brands) of 6.7 ± 1.0 mg/g (n = 25) without perturbing the cigarettes’ nicotine content (17.7 ± 0.7 mg/g [n = 25]). We also characterized other pertinent attributes of our custom-mentholated cigarettes, including percent transmission of menthol and nicotine to mainstream smoke and the rate of loss of menthol over time during storage at room temperature. We are currently using this simple mentholation technique to investigate the differences in human exposure to selected chemicals in cigarette smoke due only to the presence of the added menthol. Our cigarettes will also aid in the elucidation of the effects of menthol on the toxicity of tobacco smoke

Getting to the Top of Mind: How Reminders Increase Saving

Abstract. We develop and test a simple model of limited attention in intertemporal choice. The model posits that individuals fully attend to consumption in all periods but fail to attend to some future lumpy expenditure opportunities. This asymmetry generates some predictions that overlap with models of present-bias. Our model also generates the unique predictions that reminders may increase saving, and that reminders will be more effective when they increase the salience of a specific expenditure. We find support for these predictions in three field experiments that randomly assign reminders to new savings account holders

Using an on-site laboratory for fecal steroid analysis in wild white-faced capuchins

Beehner JC, Alfaro J, Allen C, et al. Using an on-site laboratory for fecal steroid analysis in wild white-faced capuchins. General and Comparative Endocrinology . 2022;329: 114109.Hormone laboratories located "on-site" where field studies are being conducted have a number of advantages. On-site laboratories allow hormone analyses to proceed in near-real-time, minimize logistics of sample permits/shipping, contribute to in-country capacity-building, and (our focus here) facilitate cross-site collaboration through shared methods and a shared laboratory. Here we provide proof-of-concept that an on-site hormone laboratory (the Taboga Field Laboratory, located in the Taboga Forest Reserve, Costa Rica) can successfully run endocrine analyses in a remote location. Using fecal samples from wild white-faced capuchins (Cebus imitator) from three Costa Rican forests, we validate the extraction and analysis of four steroid hormones (glucocorticoids, testosterone, estradiol, progesterone) across six assays (DetectX and ISWE, all from Arbor Assays). Additionally, as the first collaboration across three long-term, wild capuchin field sites (Lomas Barbudal, Santa Rosa, Taboga) involving local Costa Rican collaborators, this laboratory can serve as a future hub for collaborative exchange. Copyright © 2022 Elsevier Inc. All rights reserved

Using an on-site laboratory for fecal steroid analysis in wild white-faced capuchins.

Hormone laboratories located "on-site" where field studies are being conducted have a number of advantages. On-site laboratories allow hormone analyses to proceed in near-real-time, minimize logistics of sample permits/shipping, contribute to in-country capacity-building, and (our focus here) facilitate cross-site collaboration through shared methods and a shared laboratory. Here we provide proof-of-concept that an on-site hormone laboratory (the Taboga Field Laboratory, located in the Taboga Forest Reserve, Costa Rica) can successfully run endocrine analyses in a remote location. Using fecal samples from wild white-faced capuchins (Cebus imitator) from three Costa Rican forests, we validate the extraction and analysis of four steroid hormones (glucocorticoids, testosterone, estradiol, progesterone) across six assays (DetectX® and ISWE, all from Arbor Assays). Additionally, as the first collaboration across three long-term, wild capuchin field sites (Lomas Barbudal, Santa Rosa, Taboga) involving local Costa Rican collaborators, this laboratory can serve as a future hub for collaborative exchange