Snakes reproduction

Garstka, W. R., 1982, Chemical Communication and the Control of Garter Snake Reproductive Cycles, Ph.D. Diss., Harvard Univ. 

Devine, M. C. (1977). Copulatory plugs, restricted mating opportunities and reproductive competition among male garter snakes. Nature 167,345-346. 

The theory of evolution provides answers to many questions pertaining to every day fife. For instance, why are we afraid of certain animals but not of others The simple answer is that some animals are more dangerous than others, i.e. certain types of spiders or snakes are very dangerous. Therefore, it makes sense that many people are afraid of these types of animals. People who like to play with spiders or snakes may have had a slightly lower reproduction rate because some of them died when playing with these animals. 

Arnold Krochmal, Ph.D., in his hook Medicinal Plants of the United States, briefly mentions Gulf Coast Indians who made an infusion of the leaves and roots for dysentery and for relieving stomach pain. From the inner trunk bark, they also made poultices for insect and snake bites and skin ulcers. The Houma of Louisiana used a decoction of the root for sore eyes, high blood pressure, and kidney problems. The fruits of closely related species of palms have been used as medicine tWughout the Caribbean and the Yucatan in Mexico. Sabal japa fruit bears a close resemblance to the fruit of saw palmetto an extract of that fruit is used as a sedative and digestive stimulant. It was also used for respiratory problems and for weakness of the reproductive system. 

Shine R, Reed RN, Shetty S, Lemaster M, Mason RT (2002) Reproductive isolating mechanisms between two sympatric sibling species of sea snakes. Evolution 56 1655-1662... 

Greene, M. J., and Mason, R. T., 1998, Chemical mediation of reproduction in the brown tree snake, Boiga irregularis, Ecoscience 5 405-409. 

The vomeronasal system is necessary in mediating a variety of reproductive behaviors-behaviors which are clearly sexually dimorphic. A male garter snake, for example, requires an intact vomeronasal system to court a female (Kubie et al., 1978). Female mice undergo several effects in response to pheromones of male conspecifics, including induction of estrus, estrus synchrony (in group-housed females), and pregnancy... 

NATURAL HISTORY OF GARTER SNAKES AND THEIR APPLICABILITY TO STUDIES OF CHEMICAL COMMUNICATION AND REPRODUCTION... 

Aldridge, R. D., 1979, Female reproductive cycles of the snakes Arizona elegans and Crotalus viridis, Herpetologica, 35 256. 

Cieslak, E. S., 1945, Relation between the reproductive cycle and the pituitary gland in the snake Thamnophis radix. Physiol. Zool., 18 299. 

Fox, W., 1952, Seasonal variation in the male reproductive system of Pacific coast garter snakes, J. Morphol., 90 481. 

Garstka, W. R., and Crews, D., 1982, Female control of male reproductive function in a Mexican snake. Science, 217 1159. 

Whittier, J., and Crews, D., 1985, Variation in reproductive patterns of female red-sided garter snakes, Thamnophis sirtalis parietalis,... 

Snakes, as a group, are visually cryptic and auditorially impoverished. Therefore, it is probable that chemical cues are quite important in mate location. The utilization of pheromone trails in the reproductive activity of snakes has been examined to some extent in temperate zone colubrids. In these snakes, sexual behavior occurs primarily in the spring. Males leave the hibernacula first and remain in the vicinity to court the females when they emerge. At this time, female snakes leave trails for the males to follow. The pheromone involved is likely the same lipoprotein (vitellogenin) which the females produce in the liver and secrete through the skin to stimulate male courtship activity (Garstka and Crews, 1981, this volume), although the only evidence for this is that the sexual pheromone trails are also produced by skin secretions and, like a lipoprotein, are non-volatile and persistent (Ford and Low, 1984). 

Species-specific pheromone trails would be a useful prezygotic reproductive isolating mechanism as they would decrease the chance of hybrid matings. Such specificity would also save the male the energy of trailing a nonreceptive heterospecific female and reduce the male s exposure to predators. It seems likely that all species of snakes using trails in a... 

It appears from these studies that pheromone trail specificity played an early role in the evolution of species reproductive isolation in Thamnophis. Behavioral assays of trail specificity of a variety of snakes would be valuable as they may be important clues to ancestral relationships of snakes and the ecological pressures during their evolution. 

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