A preliminary study on population characteristics and ecology of the critically endangered meadow viper Vipera ursinii in the Romanian Danube Delta
2010
Strugariu, Alexandru | Zamfirescu, Ştefan | Gherghel, Iulian | Sahlean, Tiberiu | Moraru, Valentina | Zamfirescu, Oana
The present paper discusses preliminary data on population characteristics and ecology of the meadow viper Vipera ursinii in the Romanian Danube Delta. Using line transects and the Distance software, the size of the studied population was estimated at 321 (95% confidence interval: 166–618) individuals on a 62 ha area. The sex-ratio of the population was close to 1:1 and juvenile specimens were well represented. Half of the captured adult females were gravid, possibly indicating a more than annual reproductive cycle. Analysis of sexual dimorphism of 12 morphometric traits indicated significant differences only in tail length and height. No significant relationships were detected between the size, sex, age or reproductive status and the thermal ecology of the vipers. Microhabitat selection and activity patterns varied with age, sex and reproductive status and are probably linked to an onthogenetic shift in feeding ecology and to behavioral differences between reproductive and non-reproductive females.
显示更多 [+] 显示较少 [-]