V: Reptile Ecology and Behavior II2021-07-27 10:30 - 11:45 |
| Moderator: Mark Paulissen |
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1. 10:30 VIRTUAL CANCELLED - Effect of congeneric competition on size and shape variation in the Anolis carolinensis clade. Britt White*, University of Texas at Austin; Illiam Jackson, University of Texas at Austin; Melissa Kemp, University of Texas at Austin bawhite@utexas.edu
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2. 10:45 VIRTUAL Geographic Variation in the Ecomorphology and Thermal Ecology of a Widespread Lizard. Matthew Lattanzio*, Christopher Newport University; Maleah Manion, Christopher Newport University; Madison McCann, Christopher Newport University matthew.lattanzio@cnu.edu
Studies of ecomorphology reveal fascinating examples of how natural selection can mold intra- and interspecific variation in morphology–habitat associations. Despite a growing appreciation for the influence of other factors on these associations (e.g., sexual selection), our understanding of the consequences of spatial variation in their expression remains limited. Given the known ties between habitat selection and thermoregulation, one outcome of such variation might be concomitant divergence in a species’ thermal ecological traits. We capitalize on morphology, habitat use, and thermal data collected on adult Sagebrush Lizards (Sceloporus graciosus) from eight populations distributed throughout the species’ geographic range to address this limitation. In terms of their morphology, we detected no overall sexual dimorphism in body size, but there was consistent male-biased dimorphism in limb lengths and head width. Although head width and jaw length variation was unrelated to habitat use, larger lizards and lizards with longer legs exploited more open habitats compared to smaller individuals. These ecomorphological patterns were associated with concomitant variation in thermal traits: specifically, substrate temperatures varied geographically, and jointly these temperatures and habitat configuration predicted parallel variation in lizard body temperature. In general, lizards exploiting warmer perches and more heterogeneous habitats attained higher body temperatures. Overall, these findings provide some evidence that lability in thermal traits might be an underappreciated outcome of geographic variation in ecomorphology, possibly providing an important buffer against variable environmental conditions throughout a species’ range. |
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3. 11:00 VIRTUAL Morph identity predicts social behavior and contest outcomes in a color polymorphic lizard, Podarcis erhardii. Kinsey Brock*, University of California; Marie Claire Chelini, Duke University; Cole Ayton, University of California; Indiana Madden, University of California; Cynthia Ramos, University of California; Panayiotis Pafilis, National and Kapodistrian University of Athens; Danielle Edwards, University of California kbrock@ucmerced.edu
Space is a limited resource that many animals need to perform basic functions such as feeding and reproducing. Competition over access to space can induce aggressive and signaling behaviors, which may result in differential access to crucial resources related to survival and fitness. The Aegean wall lizard, Podarcis erhardii, is a tri-color polymorphic lizard that eponymously inhabits dry stone walls where they access food, safely thermoregulate, shelter from predators, and display to other lizards. Adult male color morphs exhibit physical differences in size and chemical signaling profiles, but nothing is known about potential morph-specific differences in behavior. Many color polymorphic species have behavioral morphs, which may play a role in morph evolution and maintenance. We conducted the first behavioral experiments on P. erhardii color morphs to identify morph competitive ability and characterize morph differences in behaviors involved in accessing and occupying a limited space resource. We found that male color morph identity, not size or individual identity, predicts inter-morph contest outcomes. We also found that male color morphs exhibit different levels of aggressive, chemosensory, and display behaviors, which may contribute to morph maintenance over time. |
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4. 11:15 VIRTUAL Integrating Radio Telemetry and Accelerometry to Monitor the Spatial and Temporal Movement Patterns of Snakes. Dominic DeSantis*, Georgia College and State University; Anna Tipton, Georgia College and State University; Reagan Thornton, Georgia College and State University; Rulon Clark, San Diego State University; Vicente Mata-Silva, University of Texas at El Paso; Jerry Johnson, University of Texas at El Paso; Jorge Diosdado, University of Nottingham; Amy Wagler, University of Texas at El Paso dominic.desantis@gcsu.edu
Hand-held radio telemetry has historically represented the best available tool for quantifying the movement and space use of relatively small and secretive taxa, such as snakes. However, labor-intensive protocols often limit spatial estimates of movement to relatively coarse resolutions. These constraints hinder inspection of fine-scale patterns over long time periods, precluding the detection of shifts in duration and timing of movement that might occur independently of changes in spatial metrics. The radio telemetry (RT)-tri-axial accelerometry (ACT) framework circumvents these limitations, providing protocols for simultaneous monitoring of spatial and fine-scale temporal movement patterns in rattlesnakes. The RT-ACT implants enable spatial monitoring for 10 months with continuous ACT recording (1 Hz, ± 2 g) for up to 7 months. Rechargeable batteries also enable repeated use of ACTs, enhancing cost-effectiveness. Here, we report on the recent validation of this technique with Western Diamond-backed Rattlesnakes (Crotalus atrox) in west Texas along with an ongoing extension of the RT-ACT with Timber Rattlesnakes (Crotalus horridus) in middle Georgia. Using this integrative approach, researchers can evaluate patterns associated with broader spatial and finer temporal patterns of movement and, as a result, more confidently evaluate the causes and consequences of variation in snake movement behavior. Moving forward, we aim to refine accelerometry protocols in snakes to enable remote recording of cryptic behaviors beyond general movement and immobility, including foraging, reproductive, and thermoregulatory behaviors. |
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5. 11:30 VIRTUAL Lack of aggression between neonates of the Little Brown Skink lizard; Scincella lateralis. Mark Paulissen*, Northeastern State University; Katie Fletcher, Northeastern State University paulisse@nsuok.edu
Nearly all studies of lizard aggressive behavior are of adults; there have been few studies of aggressive behavior in neonate lizards. This omits an important part of the lizard life cycle: neonate lizards tend to hatch at the same time so for a time there are large numbers of them in the habitat increasing the chances that two neonates may encounter and act aggressively toward each other. We studied the behavior of neonate Little Brown Skink (LBS) lizards by staging dyadic encounters between pairs of neonates in the laboratory, then compared the results to similar studies of adult males and adult females. Two neonates were confined in an observation chamber on either side of a partition for 48 hours. Then the partition was removed, a single retreat was placed in the observation chamber, and the behavior of the two neonates was recorded for 60 minutes. Neonate LBS almost never showed aggressive behaviors (ex. lunging or chasing) that were frequently exhibited by adult males and occasionally by adult females. The two neonates simultaneously occupied the retreat for significantly more time than did adult males or adult females. However, neonates tended to segregate themselves apart from each other on opposite sides of the observation chamber when outside the retreat—a result that matches what was found for both adult male and adult female LBS. Thus, while neonate LBS almost never display overt aggression, they stay apart from each other when active on the surface (much like adults do). |