Species Of Garter Snakes Research Articles

Responses of water snakes (Natrix r. rhombifera) and garter snakes (Thamnophis sirtalis) to chemical cues

In a series of simultaneous two-choice preference tests, water snakes (Natrix r. rhombifera) displayed a significant preference for a clean area of a test chamber vs an area soiled by a conspecific. No differential responsiveness was found for a clean area as compared to an area soiled by either a sympatric species of garter snake (Thamnophis sirtalis) or by the individual water snake Ss. A similar series of tests with individual garter snakes (Thamnophis radix) revealed significant preferences for areas soiled either by the Ss themselves or by conspecifics as compared to clean areas. No preferences were found for a clean area of the test chamber vs an area soiled by a sympatric water snake (Natrix r. r.). The possible role of chemical cues in the mediation of dispersion and social responsiveness was discussed.

Comparative Ecology of Thamnophis elegans, T. cyrtopsis, and T. rufipunctatus in New Mexico

A field and laboratory investigation was pursued to determine what ecological differences, if any, exist among three species of garter snakes, Thamnophis elegans vagrans (Baird and Girard), T. cyrtopsis cyrtopsis (Kennicott), and T. rufipunctatus (Cope), allowing them to coexist. Of the 157 garter snakes captured, 83 were T. elegans, 45 were T. cyrtopsis, and 29 were T. rufipunctatus. From the field studies it was noted that there was a definite food preference; T. rufipunctatus fed only on fish, T. cyrtopsis on amphibians, and T. elegans on amphibians, fish, and worms. Some segregation of species was indicated as to habitat. Thamnophis rufipunctatus occurred in rocky areas near still water; T. elegans were found in vegetation of various types; and T. cyrtopsis lived in both well vege- tated and rocky areas. The preferred temperature range was lower for T. rufipunc- tatus than for T. elegans and T. cyrtopsis. Thamnophis rufipunctatus and some T. cyrtopsis used refugia in rocky areas, but few T. elegans were found in rocky situ- ations and probably sought shelter in areas of logs and vegetation. Thamnophis rufipunctatus spent much of their time in water, whereas T. elegans were the most terrestrial, and T. cyrtopsis were immediate in this respect. From the laboratory experiments it was determined that body density differed between T. cyrtopsis and T. elegans with the difference reflected in the method of swimming-T. cyrtopsis swam on the surface and T. elegans below it. This behavior may have been a result of the animals ability to retain or not retain air within its lung. The differences among the species studied indicate that although the three species live in the same geographical area they do indeed live in different ecological niches. Because of these differences that allow sympatry the three species-T. elegans, T. cyrtopsis, and T. rufipunctatus-coexist. INTRODUCTION. Three species of garter snake, western garter snake, Thamophis elegans vagrans (Baird and Girard), black-necked garter snake, T. cyrtopsis cyrtopsis (Kennicott), and narrow-headed garter snake, T. rufipunctatus (Cope), occur in the same area around Wall Lake, Catron County, New Mexico. During the summers of 1959-1962 a field and laboratory investigation was pursued to de- termine the specific ecological requirements of each species that allow them to coexist.

Semiaquatic Snakes of the Genus Thamnophis from the Isolated Drainage System of the Rio Nazas and Adjacent Areas in Mexico

Several streams traversing portions of the Chihuahuan Desert in northern Mexico were once part of a master river system, the Pleistocene or postPleistocene Rio Nazas, which emptied into the Rio Grande during one or more pluvial periods of the past. Several species of fishes, the turtle, Pseudemys scripta, and the water snake, Natrix erythrogaster, which occur in one or more of the now isolated drainage systems, are identical with or only subspecifically distinct from their counterparts in the Rio Grande. It is assumed that these aquatic and semiaquatic vertebrates achieved their present relict distributions in the desert by working headward from the Rio Grande. Three species of garter snakes, Thamnophis eques, T. melanogaster, and T. rufipunctatus, are also closely associated with the now disrupted streams. A detailed study of scutellation and pattern variations among the Thamnophis populations from the several rivers and adjacent areas suggests that migration along the streams contributed to present-day distribution patterns, but that a more important factor was probably overland movement during the pluvials. All three species of Thamnophis are widespread upon the Mexican plateau, and none is known to occur in the Rio Grande system downstream from the Rio Conchos in Chihuahua. A new race of Thamnophis eques from high elevations in the Sierra Madre Occidental of Durango and Chihuahua is described.

Oxygen Consumption and Q 10 for Two Species of Garter Snakes (Genus Thamnophis)

Introduction In the summer of 1961, in connection with field studies, I had the opportunity to conduct some comparative physiological experiments on two species of garter snakes, Thamnophis dorsalis (Kennicott) and T. elegans (Baird and Girard). The suggestions received during the course of this work from Professors James S. Findley, Eugene W. Rypka, and Marvin Riedesel are greatly appreciated. I received financial support from the Danforth Foundation which is gratefully acknowledged.

Life History Studies on Trematodes of the Subfamily Reniferinae

1. The life histories of Lechriorchis primus Stafford, L. tygarti n.sp. and Caudorchis eurinus n.gen. et sp. have been experimentally completed in three hosts, the first complete life histories to be worked out for species of the subfamily Reniferinae.2. The definitive hosts of the three forms were found to be two species of garter snakes, Thamnophis sauritus and T. sirtalis.3. Three species of snails, Physella gyrina, P. parkeri, and P. ancillaria, have been found to serve as the first intermediate host in the life cycles of Lechriorchis primus and Caudorchis eurinus n.gen. et sp., and two species of snails, Physella gyrina and P. heterostropha, in the life cycle of Lechriorchis tygarti n.sp.4. The tadpoles of two species of frogs, Rana clamitans and R. pipiens, were found to serve as the second intermediate hosts in the life cycles of all three trematodes. The cercariae penetrate larvae of Triturus and small fish, but live only a short time in these animals.5. Every stage in the life history of Lechriorchis primus, including egg, miracidium, mother sporocyst, daughter sporocyst, cercaria, metacercaria, and developmental stages in the definitive host, has been described in detail.6. The mother sporocyst of forms having a stylet cercaria is described for the first time.7. The flame cell pattern of the cercariae of L. primus, L. tygarti n.sp., and Caudorchis eurinus n.gen. et sp. has been determined to be of the “2 × 6 × 3’ type. Also the adult stage of C. eurinus was determined to have the same type.8. It has been pointed out that the life histories of the members of the subfamily are uniform in that their life history stages display a remarkable similarity.9. It has been suggested that this uniform type of life cycle and remarkable similarity of larval stages offer the most logical basis for establishing the subfamily Reniferinae as a natural group.

The Significance of Knobbed Anal Keels in the Garter Snake, Thamnophis sirtalis sirtalis (Linnaeus)

RECENTLY attention has been called by F. N. Blanchard' to certain peculiarities of the dorsal scales of the anal region in various species of snakes. These peculiarities are manifested as keel-like structures on smooth-scaled snakes, and as excrescences or knobs on the keels of keeled snakes. To determine the significance of these excrescences and their relation to sex and age in a species of garter snake, study was made at the suggestion of Dr. Blanchard of a series of 400 specimens of Thamnophis sirtalis sirtalis. All the specimens were loaned by the Museum of Zoology of the University of Michigan through the courtesy of Mrs. Helen T. Gaige, Curator of Amphibians. In this species of garter snake, the well developed knobbed keels usually occur in the immediate vicinity of the anus, extending dorsally as high as the third or fourth row of scales. Keels with poorly developed excrescences may occur several millimeters farther anteriorly and posteriorly, and dorsally to the median line. Ordinarily, however, even poorly developed knobs do not appear higher up than the sixth or seventh dorsal scale rows.