Demography of an Urban Population of Ring-necked Snakes ( Diadophis punctatus ) in Missouri.

摘要

Snakes are generally considered poor subjects for studies of population and community ecology because of low recapture rates and high variability in density and survival estimates. Some species, though, can be found seasonally in large numbers and thus may be good model organisms for life-history studies. I conducted a capture- mark-recapture study on an urban population of Ring-necked Snakes (Diadophis punctatus) in Jefferson City, Missouri, USA over three years to determine population structure and growth rates. I divided the population into three age classes: Year 1, Year 2, and Adult (≥ 3 y of age). Survivorship varied depending on age, but recapture probabilities were low across all age classes. Less than half of the population was predicted to survive to reach 3 y of age, although a λ value of 1.23 signified a growing population. Sensitivity of age classes suggests that population trajectories are reliant upon recruitment of year-class two individuals into their third year of life.