Behavior

Anonymous (2004). Growing interest in reptile behaviour. Veterinary Record 154(16): 485-486. ISSN: 0042-4900.
NAL Call Number: 41.8 V641
Descriptors: reptiles, animal husbandry, behavior, animal.

Anonymous (2004). Managing reptile behaviour. Journal of Small Animal Practice. 45(6): 330. ISSN: print: 0022-4510; online: 1748-5827.
NAL Call Number: 41.8 J8292
Descriptors: reptiles, animal husbandry, behavior, captivity, care.

Belliure, J. and J. Clobert (2004). Behavioral sensitivity to corticosterone in juveniles of the wall lizard, Podarcis muralis. Physiology and Behavior 81(1): 121-127. ISSN: 0031-9384.
Abstract: Reptiles exposed to stressful conditions respond with increases in plasma levels of corticosterone (CORT). The outcome of such hormonal fluctuations can affect the organism's physiology and behavior; however, relatively few studies in reptiles have progressed past the effects of stress on the plasma levels of CORT. The purpose of this study was to investigate the effects of CORT on lizard behavior. We focused on activity and thermoregulation of juveniles of the wall lizard, Podarcis muralis. Juveniles with experimentally elevated plasma CORT concentrations showed a higher moving rate and spent a greater amount of time moving. They also spent more time being involved in attempts to escape from a terrarium. This enhanced locomotor activity was associated with significant changes in thermoregulatory behavior, as CORT-increased individuals had reduced thermoregulatory activity than the controls. The same pattern of results was obtained in nature and under laboratory conditions. Thus, CORT levels appear to mediate an important trade-off between locomotor activity and thermoregulation. To our knowledge, this is the first time that the effect of CORT on lizard thermoregulation has been examined.
Descriptors: reptiles, wall lizard, Podarcis muralis, juveniles, corticosterone, behavioral sensitivity, stressful conditions, plasma levels.

Bradshaw, C.J., C.R. McMahon, and G.C. Hays (2007). Behavioral inference of diving metabolic rate in free-ranging leatherback turtles. Physiological and Biochemical Zoology 80(2): 209-219. ISSN: 1522-2152.
NAL Call Number: QL1.P52
Abstract: Good estimates of metabolic rate in free-ranging animals are essential for understanding behavior, distribution, and abundance. For the critically endangered leatherback turtle (Dermochelys coriacea), one of the world's largest reptiles, there has been a long-standing debate over whether this species demonstrates any metabolic endothermy. In short, do leatherbacks have a purely ectothermic reptilian metabolic rate or one that is elevated as a result of regional endothermy? Recent measurements have provided the first estimates of field metabolic rate (FMR) in leatherback turtles using doubly labeled water; however, the technique is prohibitively expensive and logistically difficult and produces estimates that are highly variable across individuals in this species. We therefore examined dive duration and depth data collected for nine free-swimming leatherback turtles over long periods (up to 431 d) to infer aerobic dive limits (ADLs) based on the asymptotic increase in maximum dive duration with depth. From this index of ADL and the known mass-specific oxygen storage capacity (To(2)) of leatherbacks, we inferred diving metabolic rate (DMR) as To2/ADL. We predicted that if leatherbacks conform to the purely ectothermic reptilian model of oxygen consumption, these inferred estimates of DMR should fall between predicted and measured values of reptilian resting and field metabolic rates, as well as being substantially lower than the FMR predicted for an endotherm of equivalent mass. Indeed, our behaviorally derived DMR estimates (mean=0.73+/-0.11 mL O(2) min(-1) kg(-1)) were 3.00+/-0.54 times the resting metabolic rate measured in unrestrained leatherbacks and 0.50+/-0.08 times the average FMR for a reptile of equivalent mass. These DMRs were also nearly one order of magnitude lower than the FMR predicted for an endotherm of equivalent mass. Thus, our findings lend support to the notion that diving leatherback turtles are indeed ectothermic and do not demonstrate elevated metabolic rates that might be expected due to regional endothermy. Their capacity to have a warm body core even in cold water therefore seems to derive from their large size, heat exchangers, thermal inertia, and insulating fat layers and not from an elevated metabolic rate.
Descriptors: reptiles, leatherback turtles, diving metabolic rate, behavioral inference, metabolic rate, ectothermic, warm body core.

Fox, S.F., J.K. McCoy and T.A. Baird (Editors) (2003). Lizard Social Behavior, Johns Hopkins University Press: Baltimore, MD, 438 p. ISBN: 0801868939.
NAL Call Number: QL666.L2 L59 2003
Descriptors: reptiles, lizards, social behavior in animals.

Gao, Z.f. (2005). Observation on behavior and reproduction of some reptiles under artificial breeding condition. Sichuan Journal of Zoology 24(2): 180. ISSN: 1000-7083.
Descriptors: reptiles, reproduction, observation, artificial breeding condition, behavior.
Language of Text: Chinese.

Gregory, P.T. and L.a. Gregory (2006). Immobility and supination in garter snakes (Thamnophis elegans) following handling by human predators. Journal of Comparative Psychology 120(3): 262-268. ISSN: 0735-7036.
Descriptors: reptiles, garter snakes, Thamnophis elegans, immobility, following handling, human predators, physical restraint, response.

Hoglund, E., W.J. Korzan, M.J. Watt, G.L. Forster, T.R. Summers, H.F. Johannessen, K.J. Renner, and C.H. Summers (2005). Effects of L-DOPA on aggressive behavior and central monoaminergic activity in the lizard Anolis carolinensis, using a new method for drug delivery. Behavioural Brain Research 156(1): 53-64. ISSN: 0166-4328.
Abstract: The dopamine (DA) precursor, L-DOPA (500 microg), was injected into living crickets, which were ingested (one each) by adult male Anolis carolinensis. This method of delivery elevated plasma L-DOPA and DA concentrations by approximately 1000-fold. In contrast, plasma epinephrine (Epi) and norepinephrine (NE) were not influenced by L-DOPA treatment, although they were elevated following the consumption of the cricket. Lizards that ingested L-DOPA treated crickets had elevated L-DOPA in all brain regions measured, with DA and/or DOPAC also increased significantly in most brain regions studied. Despite increased DA levels in the striatum and nucleus accumbens as a response to L-DOPA, the treatment had no influence on general motor activity. Central serotonin, NE, and Epi systems were not affected in any brain region by oral L-DOPA treatment. In addition, aggression was inhibited by this dose of L-DOPA, even though there was no effect on serotonergic systems. This is surprising because controlling aggressive behavior is usually considered the province of serotonergic activity. Aggression was measured before and after treatment, and while saline-treated lizards retained the full vigor of aggressive activity, those fed a cricket injected with L-DOPA were only one-third as aggressive after treatment. As L-DOPA treatment did not affect general motor activity, the effect appears to be directly associated with aggression. This is supported by the observation that L-DOPA treatment delayed latency to eyespot darkening, which predicts the latency to aggression.
Descriptors: lizard, Anolis carolinensis, behavior, L-DOPA, agressive behavior, central monoaminergic activity, drug delivery method, crickets, dopamine.

Irwin, W.P. and K.J. Lohmann (2005). Disruption of magnetic orientation in hatchling loggerhead sea turtles by pulsed magnetic fields. Journal of Comparative Physiology. A, Neuroethology, Sensory, Neural, and Behavioral Physiology 191(5): 475-480. ISSN: 0340-7594.
NAL Call Number: QP33.J68
Abstract: Loggerhead sea turtles (Caretta caretta) derive both directional and positional information from the Earth's magnetic field, but the mechanism underlying magnetic field detection in turtles has not been determined. One hypothesis is that crystals of biogenic, single-domain magnetite provide the physical basis of the magnetic sense. As a first step toward determining if magnetite is involved in sea turtle magnetoreception, hatchling loggerheads were exposed to pulsed magnetic fields (40 mT, 4 ms rise time) capable of altering the magnetic dipole moment of biogenic magnetite crystals. A control group of turtles was treated identically but not exposed to the pulsed fields. Both groups of turtles subsequently oriented toward a light source, implying that the pulsed fields did not disrupt the motivation to swim or the ability to maintain a consistent heading. However, when swimming in darkness under conditions in which turtles normally orient magnetically, control turtles oriented significantly toward the offshore migratory direction while those that were exposed to the magnetic pulses did not. These results are consistent with the hypothesis that at least part of the sea turtle magnetoreception system is based on magnetite. In principle, a magnetite-based magnetoreception system might be involved in detecting directional information, positional information, or both.
Descriptors: loggerhead sea turtles, Caretta caretta, electromagnetic fields, magnetic disruption, orientation, turtle physiology, pulsed magnetic fields.

James, M.C., R.A. Myers, and C.A. Ottensmeyer (2005). Behaviour of leatherback sea turtles, Dermochelys coriacea, during the migratory cycle. Proceedings of the Royal Society. Biological Sciences. Series B 272(1572): 1547-1555. ISSN: 0962-8452.
NAL Call Number: 501 L84B
Descriptors: reptiles, leatherback sea turtle, Dermochelys coriacea, aquatic diving, behavior during migratory cycle.

Kabelik, D., S.L. Weiss, and M.C. Moore (2006). Steroid hormone mediation of limbic brain plasticity and aggression in free-living tree lizards, Urosaurus ornatus. Hormones and Behavior 49(5): 587-597. ISSN: 0018-506X.
NAL Call Number: QP801.H7H64
Abstract: The neural mechanisms by which steroid hormones regulate aggression are unclear. Although testosterone and its metabolites are involved in both the regulation of aggression and the maintenance of neural morphology, it is unknown whether these changes are functionally related. We addressed the hypothesis that parallel changes in steroid levels and brain volumes are involved in the regulation of adult aggression. We examined the relationships between seasonal hormone changes, aggressive behavior, and the volumes of limbic brain regions in free-living male and female tree lizards (Urosaurus ornatus). The brain nuclei that we examined included the lateral septum (LS), preoptic area (POA), amygdala (AMY), and ventromedial hypothalamus (VMH). We showed that the volumes of the POA and AMY in males and the POA in females vary with season. However, reproductive state (and thus hormonal state) was incompletely predictive of these seasonal changes in males and completely unrelated to changes in females. We also detected male-biased dimorphisms in volume of the POA, AMY, and a dorsolateral subnucleus of the VMH but did not detect a dimorphism between alternate male morphological phenotypes. Finally, we showed that circulating testosterone levels were higher in males exhibiting higher frequency and intensity of aggressive display to a conspecific, though brain nucleus volumes were unrelated to behavior. Our findings fail to support our hypothesis and suggest instead that plasma testosterone level covaries with aggression level and in a limited capacity with brain nucleus volumes but that these are largely unrelated relationships.
Descriptors: reptiles, free living tree lizards, Urosaurus ornatus, steroid hormonelimbic brain plasticity, aggression, testosterone.
Notes: Comment In: Horm Behav. 2006 May;49(5):577-9.

Lappin, A.K. and M. German (2005). Feeding behavior modulation in the leopard lizard (Gambelia wislizenii): Effects of noxious versus innocuous prey. Zoology [Jena] 108(4): 287-295. ISSN: 0944-2006.
NAL Call Number: QL1.Z769
Abstract: Feeding, a fundamentally rhythmic behavior in many animals, is expected to exhibit modulation with respect to prey type. Using high-speed videography (200 frames(-1)) and kinematic analysis, we investigated prey-processing behavior in the long-nosed leopard lizard (Gambelia wislizenii). The effects of two prey types were examined, innocuous immature crickets (Acheta domesticus) and noxious stinging hymenopterans (honeybees [Apis mellifer] and yellow jackets [Vespula sp.]). Stinging hymenopterans are processed more extensively, with higher gape-cycling frequencies, and for a greater duration than are crickets. Generalized tetrapod feeding models were used as a framework to test the hypothesis that gape profile characteristics are modulated in response to prey noxiousness. Cricket processing generally fits the models, but hymenopteran processing departs from typical model parameters. In particular, the SO phase is absent to barely detectable during hymenopteran processing. This likely represents an effect of extrinsic neural input on a centrally directed rhythmic motor pattern, possibly to avoid being stung. Differences in the capture behavior of crickets versus hymenopterans indicate that G. wislizenii assesses prey noxiousness before physical contact with prey and modifies its capture behavior accordingly. These results add to the growing body of evidence that sensory information can play a critical role in shaping stereotyped rhythmic behaviors in non-mammalian tetrapods.
Descriptors: long-nosed leopard lizard (Gambelia wislizenii), feeding behavior, lizards physiology, modulation, prey type, innocuous prey, noxious prey.

LeMaster, M.P. and R.T. Mason (2002). Variation in a female sexual attractiveness pheromone controls male mate choice in garter snakes. Journal of Chemical Ecology 28(6): 1269-1285. ISSN: print: 0098-0331; online: 1573-1561.
Abstract: Male red-sided garter snakes (Thamnophis sirtalis parietalis) display a courtship preference for larger females during the breeding season. Utilizing behavioral experiments and chemical analyses, we tested the hypothesis that males can discriminate among females of varying size solely by means of the sexual attractiveness pheromone, a previously characterized sex pheromone composed of a homologous series of long-chain saturated and omega-9 cis-unsaturated methyl ketones contained in the skin lipids of females. When presented with skin lipid extracts from large and small females, a greater proportion of males displayed courtship behaviors to large female extracts. This demonstrates that there is an intrinsic property of the female skin lipids that allows males to differentiate among large and small females. Analysis of the sexual attractiveness pheromone revealed that the necessary variation exists for this pheromone to function as a reliable indicator to males of female body size. Specifically, we observed a strong correlation between female snout-vent length and the relative concentration of saturated and omega-9 cis-unsaturated methyl ketones composing the pheromone; smaller females expressed pheromone profiles higher in saturated methyl ketones. while larger females expressed pheromone profiles dominated by unsaturated methyl ketones. The results of this study suggest that male red-sided garter snakes utilize compositional variation in the female sexual attractiveness pheromone to differentiate among potential mates of varying size.
Descriptors: reptiles, garter snakes, Thamnophis sirtalis parietalis, female sexual attractiveness, variation, pheromone controls, mate choice, preference for larger females.

Loehr, V.J.T. (2006). Captive husbandry of the dwarf plated lizard, Cordylosaurus subtessellatus (Smith, 1844), with indications for ecological and behavioural characteristics. Herpetological Bulletin(96): 5-11. ISSN: 1473-0928.
Descriptors: reptiles, dwarf plated lizard, Cordylosaurus subtessellatus, captive husbandry, behavioral characteristics, activity pattern, mating.

Lutterschmidt, D.I., W.I. Lutterschmidt, N.B. Ford, and V.H. Hutchison (2002). Behavioral thermoregulation and the role of melatonin in a nocturnal snake. Hormones and Behavior 41(1): 41-50. ISSN: 0018-506X.
NAL Call Number: QP801.H7H64
Abstract: Daily and seasonal variations in hormone levels influence the complex interactions between behavior and physiology. Ectothermic animals possess the unique ability behaviorally to adjust body temperature (T(b)) to control physiological rate processes. Thus, a hormone may indirectly influence a physiological rate by directly influencing the behaviors that adjust or control that rate process. Although many hormonal influences on behavioral regulation of T(b) remain uninvestigated, melatonin (MEL) generally is considered a hormone that decreases mean preferred T(b). Many ectotherms demonstrate the selection of lower T(b)'s in response to increased MEL concentrations. Here, we examined the influence of MEL on the behavioral regulation of T(b) in the nocturnal African house snake Lamprophis fuliginosus. A series of experiments with two injection regimes of MEL had no significant effect on the mean preferred T(b) of L. fuliginosus. In addition, mean preferred T(b)'s during the photophase did not differ significantly from those during scotophase. Our findings suggest that L. fuliginosus does not respond to elevated concentrations of either endogenous or exogenous MEL. To verify that the African house snake is nocturnal, we investigated activity patterns of L. fuliginosus throughout the photoperiod. The activity period of L. fuliginosus occurs in the scotophase of the photoperiod, a pattern consistent with that of nocturnal species. This suggests that nocturnal organisms such as L. fuliginosus may not respond to MEL in the same manner as many diurnal species. Our results support the hypothesis that some animals, particularly nocturnal species, may have developed alternative responses to increased plasma concentrations of MEL.
Descriptors: reptiles, nocturnal snake, Lamprophis fuliginosus, behavioral thermoregulation, role of melatonin, body temperature.

McMann, S. and A.V. Paterson (2003). Effects of capture, observer presence, and captivity on display behavior in a lizard. Journal of Herpetology 37(3): 538-540. ISSN: 0022-1511.
NAL Call Number: QL640.J6
Descriptors: reptiles, lizard, behavior, captivity, display, observer presence, capture, effects.

Powell, R. (2006). Lizard warfare. Iguana 13(1): 22-23. ISSN: 1554-916X.
Descriptors: reptiles, lizard, warfare, fighting behavior.

Rubenstein, D.R. and M. Wikelski (2005). Steroid hormones and aggression in female Galapagos marine iguanas. Hormones and Behavior 48(3): 329-341. ISSN: 0018-506X.
NAL Call Number: QP801.H7H64
Descriptors: reptiles, Galapagos marine iguanas, steroid hormones, aggression, female.

Sale, A., P. Luschi, R. Mencacci, P. Lambardi, G.R. Hughes, G.C. Hays, S. Benvenuti, and F. Papi (2006). Long-term monitoring of leatherback turtle diving behaviour during oceanic movements. Journal of Experimental Marine Biology and Ecology 328(2): 197-210. ISSN: 0022-0981.
Descriptors: reptiles, leatherback turtle, Dermochelys coriacea, diving behavior, oceanic movements, long term monitoring.

Seebacher, F., C.E. Franklin, and M. Read (2005). Diving behaviour of a reptile (Crocodylus johnstoni) in the wild: interactions with heart rate and body temperature. Physiological and Biochemical Zoology 78(1): 1-8. ISSN: 1522-2152.
NAL Call Number: QL1.P52
Abstract: The differences in physical properties of air and water pose unique behavioural and physiological demands on semiaquatic animals. The aim of this study was to describe the diving behaviour of the freshwater crocodile Crocodylus johnstoni in the wild and to assess the relationships between diving, body temperature, and heart rate. Time-depth recorders, temperature-sensitive radio transmitters, and heart rate transmitters were deployed on each of six C. johnstoni (4.0-26.5 kg), and data were obtained from five animals. Crocodiles showed the greatest diving activity in the morning (0600-1200 hours) and were least active at night, remaining at the water surface. Surprisingly, activity pattern was asynchronous with thermoregulation, and activity was correlated to light rather than to body temperature. Nonetheless, crocodiles thermoregulated and showed a typical heart rate hysteresis pattern (heart rate during heating greater than heart rate during cooling) in response to heating and cooling. Additionally, dive length decreased with increasing body temperature. Maximum diving length was 119.6 min, but the greatest proportion of diving time was spent on relatively short (<45 min) and shallow (<0.4 m) dives. A bradycardia was observed during diving, although heart rate during submergence was only 12% lower than when animals were at the surface.
Descriptors: alligators, crocodiles, Crocodylus johnstoni, physiology, body temperature regulation, diving physiology, heart rate, diving behavior, activity pattern, air, water, physical properties.

Somma, L.A. (2003). A few more additions to the literature on parental behavior in lizards and snakes. Bulletin of the Chicago Herpetological Society 38(11): 217-220. ISSN: 0009-3564.
Descriptors: reptiles, parental behavior, lizards, snakes, literature.

Somma, L.A. (2003). Parental Behavior in Lepidosaurian and Testudinian Reptiles: A Literature Survey., Krieger Publishing Company: Malabar, Florida, 174 p. ISBN: 157524201X.
Descriptors: reptiles, lepidosauria, testudinian, literature survey, parental behavior.

Wade, J. (2005). Current research on the behavioral neuroendocrinology of reptiles. Hormones and Behavior 48(4): 451-460. ISSN: 0018-506X.
NAL Call Number: QP801.H7H64
Abstract: Selected reptilian species have been the targets of investigations in behavioral neuroendocrinology for many years. Reptiles offer a particularly powerful set of traits that facilitate comparisons at multiple levels, including those within and between individuals of a particular species, between different environmental and social contexts, as well as across species. These types of studies, particularly as they are considered within the framework of results from other vertebrates, will enhance our understanding of the genetic and hormonal influences regulating changes in the structure and function of the nervous system. Work on the hormonal and environmental factors influencing courtship and copulatory behaviors in green anoles, including the development and maintenance of the neuromuscular structures critical for their display, is highlighted. Some very recent work on other model systems is also discussed to provide a context for suggested future research directions.
Descriptors: reptiles, behavior, physiology, neurosecretory systems, physiology, reproduction physiology, sexual behavior, gonadal steroid hormones.

Wassersug, R.J., L. Roberts, J. Gimian, E. Hughes, R. Saunders, D. Devison, J. Woodbury, and J.C. O'Reilly (2005). The behavioral responses of amphibians and reptiles to microgravity on parabolic flights. Zoology [Jena] 108(2): 107-120. ISSN: 0944-2006.
NAL Call Number: QL1.Z769
Abstract: In the present study, we exposed 53 animals from 23 different species of amphibians and reptiles to microgravity (mug). This nearly doubles the number of amphibians and reptiles observed so far in mug. The animals were flown on a parabolic flight, which provided 20-25s of mug, to better characterize behavioral reactions to abrupt exposure to mug. Highly fossorial limbless caecilians and amphisbaenians showed relatively limited movement in mug. Limbed quadrupedal reptiles that were non-arboreal in the genera Leiocephalus, Anolis, and Scincella showed the typical righting response and enormous amounts of body motion and tail rotation, which we interpreted as both righting responses and futile actions to grasp the substrate. Both arboreal and non-arboreal geckos in the genera Uroplatus, Palmatogecko, Stenodactylus, Tarentola, and Eublepharis instead showed a skydiving posture previously reported for highly arboreal anurans. Some snakes, in the genera Thamnophis and Elaphe, which typically thrashed and rolled in mug, managed to knot their own bodies with their tails and immediately became quiescent. This suggests that these reptiles gave stable physical contact, which would indicate that they were not falling, primacy over vestibular input that indicated that they were in freefall. The fact that they became quiet upon self-embrace further suggests a failure to distinguish self from non-self. The patterns of behavior seen in amphibians and reptiles in mug can be explained in light of their normal ecology and taxonomic relations.
Descriptors: various species of reptiles and amphibians, gravity perception, physiology, hypogravity, motor activity, microgravity (mug), behavioral reactions.

Waterloo, B. and M.K. Bayless (2006). Notes on the breeding behaviour of the crocodile monitor (Varanus salvadorii) in captivity. Herpetological Bulletin(98): 2-6. ISSN: 1473-0928.
Descriptors: reptiles, crocodile monitor, captive, Varanus salvadorii, breeding behavior, notes, husbandry, care.

Weiss, S.L. and M.C. Moore (2004). Activation of aggressive behavior by progesterone and testosterone in male tree lizards, Urosaurus ornatus. General and Comparative Endocrinology 136(2): 282-288. ISSN: 0016-6480.
NAL Call Number: 444.8 G28
Abstract: Testosterone is usually thought to be the major sex steroid regulating adult male territorial aggression in vertebrates. However, recent evidence has suggested a role for progesterone, as well as testosterone, in the organization of the two male reproductive phenotypes of tree lizards (Urosaurus ornatus), which differ in adult levels of territorial behavior. In the present experiment we tested whether progesterone and testosterone could also play an activational role in the expression of adult aggressive behavior. We subjected post-reproductive male tree lizards to the following treatments: sham surgery, castration, castration with progesterone supplementation, and castration with testosterone supplementation. We measured several different dimensions of aggressive behavior. Overall in these post-reproductive animals, the level of aggression from lowest to highest was: castrates, shams, progesterone-treated, and testosterone-treated. Although testosterone appears to be the more potent regulator of aggressive behavior, progesterone enhanced several measures of aggression suggesting that it could play a role in natural regulation of aggressive behavior. This initial study used very high levels of progesterone (similar to or above those experienced by hatchlings) to maximize the probability of detecting an effect. Further studies are needed to determine if natural adult progesterone levels are sufficiently high to influence aggressive behavior.
Descriptors: reptiles, male tree lizards, Urosaurus ornatus, aggressive behavior, activation, testosterone, progesterone.

Woolley, S.C., J.T. Sakata, and D. Crews (2004). Evolutionary insights into the regulation of courtship behavior in male amphibians and reptiles. Physiology and Behavior 83(2): 347-360. ISSN: 0031-9384.
Abstract: Comparative studies of species differences and similarities in the regulation of courtship behavior afford an understanding of evolutionary pressures and constraints shaping reproductive processes and the relative contributions of hormonal, genetic, and ecological factors. Here, we review species differences and similarities in the control of courtship and copulatory behaviors in male amphibians and reptiles, focusing on the role of sex steroid hormones, the neurohormone arginine vasotocin (AVT), and catecholamines. We discuss species differences in the sensory modalities used during courtship and in the neural correlates of these differences, as well as the value of particular model systems for neural evolution studies with regard to reproductive processes. For example, in some genera of amphibians (e.g., Ambystoma) and reptiles (e.g., Cnemidophorus), interspecific hybridizations occur, making it possible to compare the ancestral with the descendant species, and these systems provide a window into the process of behavioral and neural evolution as well as the effect of genome size. Though our understanding of the hormonal and neural correlates of mating behavior in a variety of amphibian and reptilian species has advanced substantially, more studies that manipulate hormone or neurotransmitter systems are required to assess the functions of these systems.
Descriptors: amphibians, reptiles, courtship behavior, male, hormonal, genetic, species differences, copulatory behaviors.