Animal Sciences Commons^™

Trophic Interactions In A Semiaquatic Snake Community: Insights Into The Structure Of A Floodplain Food Web, Cynthia M. Carter

Masters Theses

Food webs provide a useful conceptual framework for evaluating the relationships that exist within ecological systems. Characterizing the interactions within these webs can improve our understanding of how communities are structured and what mechanisms stabilize them. Untangling these interactions can be an intractable problem in complex systems and insights gained from conventional methods are often accompanied by inherent sources of bias. This study used stable isotope analysis, an alternative to traditional methods, to investigate the roles and relative contributions of consumers at the top of a food web to community structure and stability. I compared the niche parameters of five …

Predator Deterrence In The Central Newt, Notophthalmus Viridescens Louisianensis (Wolterstorff) With Notes On Salamander Antipredator Strategies, Malcolm Mccallum

Masters Theses

The effectiveness of the skin secretions of Notophthalmus viridescens as a predator deterrent has been well documented. Still, there have been documented cases of predation on this salamander. This study investigates the ability of a variety of herptiles to feed on N. viridescens louisianensis.

In the first experiment, plethodonts and efts were fed on alternate weeks to snakes. Latency of response, anatomical location of predator attack, and behaviors displayed by predators and prey were recorded during each trial.

In the second experiment, tongue flick frequency by T. sirtalis to the essence of live N. viridescens louisianensis, Eurycea cirigerra …

Factors Affecting The Predator-Prey Relationship Between Predaceous Diving Beetle Larvae (Dytiscus Fasciventris) And Two Anuran Tadpole Species (Bufo Americanus And Hyla Crucifer), Todd S. Campbell

Masters Theses

It has previously been demonstrated that American toad (Bufo americanus) tadpoles are more vulnerable to predation by diving beetle larvae (Dytiscus fasciventris) than are spring peeper (Hyla crucifer) tadpoles. A laboratory study was undertaken to further delineate factors that contribute to the differential vulnerability observed. Beetle larvae are more effective tadpole predators in shallow, than in deep, water and appear to prefer to adopt a "sit-and-wait" predator strategy while clinging to emergent vegetation. Depth preference experiments in the laboratory indicated that both tadpole species prefer deep areas to shallow areas irrespective of whether a …

The Hold-Release Mechanism In The Family Crotalidae, Ronald K. Easter

Masters Theses

Strike/release vs. strike/hold feeding behavior was observed for 5 Crotalus atrox and 5 Agkistrodon piscivorous. Two sizes of warm blooded prey were offered to the rattlesnakes on alternate weeks. Cottonmouths were offered, alternately, fish or mice of equal size. Although data varied among individual subjects, cottonmouths offered fish demonstrated the strike/hold behavior significantly more often than the strike/release behavior; cottonmouths offered mice struck and released significantly more often than they struck and held. It is concluded that the strike/hold strategy in sreponse to fish is adventageous because the danger of holding such prey is minimal and the release of …

Observations On Relationships Between Limb Measurements And Mode Of Locomotion In Malaysian Turtles, Duayne Nyckel

Masters Theses

Twelve Genera (spanning three Families) of Malaysian Turtles were studied to determine whether bone lengths could be correlated to mode of locomotion. Ulna, humerus, tibia, femur, coracoid (among others) were measured and results were presented graphically. Five of the genera were observed singly in a large aquarium. Data were recorded on the amount of time each spent in different locomotor modes. Both limb length data and aquarium observations suggest that turtles can be grouped into three main locomotor habits (i.e. terrestrial walking, bottomwalking, and swimming). The terrestrial group includes the genera, Geochelone, Kinixys, and Gopherus. Bottomwalkers include …

Operant Conditioning In The Water Snake (Nerodia Sipedon), Angela R. Deitz

Masters Theses

Six subjects of Nerodia sipedon were tested for runway acquisition. Five of six subjects met criterion for runway learning, demonstrating a significant decrease over the 25 day testing period in mean latency and running times. Four subjects completed 170 trials in a T-maze to test two-choice discrimination and reversal learning. All subjects met criterion for the initial discrimination and one reversal while two subjects completed four reversals and one subject met criterion for six reversals. Results are similar or superior to those previously reported for reptiles and other non-human vertebrates.

Ecological Comparisons Of Four Plethodontid Salamanders In A Ravine In West Central Indiana, Stephen L. Reinbold

Masters Theses

No abstract provided.

Defensive Behavior Of The Hognose Snake (Heterodon Platyrhinos), Brenda S. Hemken

Masters Theses

Fourteen out of sixteen Heterodon platyrhinos eggs were hatched in late August, 1973. The immature snakes were manually stimulated and the resultant bluffing and death-feigning behaviors were observed. All of the experimental snakes bluffed, but only three out of ten feigned death. The major components of the bluffing behavior are spreading the neck, hissing, and striking. Death-feigning is preceded by contortions and shows variations in the positions of the mouth and tongue. The newly-hatched snakes exhibited both bluffing and death-feigning, indicating that the behaviors are innate.

Operant Conditioning In The Garter Snake (Thamnophis), William A. Schmitz

Masters Theses

Ten garter snakes were tested for runway acquisition, correct turn response in a simple T-maze, or both, for food reinforcement. Seven of seven subjects met criterion for learning to run a 23 inch long alleyway. Mean latency times showed a general decrease over a 23 day period. Five of nine subjects met criterion for learning a correct turn response in a simple T-maze. Subjects mastering the task required from 14-157 trials. One of two subjects met criterion for learning the reverse response of the T-maze exercise, requiring 35 trials. Results are similar to those previously reported for reptiles and other …