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首页> 外文期刊>Chelonian conservation and biology >Long-Term Trends in Ringed Sawback (Graptemys oculifera) Growth, Survivorship, Sex Ratios, and Population Sizes in the Pearl River, Mississippi
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Long-Term Trends in Ringed Sawback (Graptemys oculifera) Growth, Survivorship, Sex Ratios, and Population Sizes in the Pearl River, Mississippi

机译：密西西比州珠江的环锯木背（Graptemys oculifera）生长，存活率，性别比和人口规模的长期趋势

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摘要

Effective management of long-lived species requires demographic and life-history data that are best acquired from long-term studies. The ringed sawback (Graptemys oculifera), endemic to the Pearl River watershed of Mississippi and Louisiana, is a species of management concern at both the state and federal levels. Population sizes, trapping success, basking counts, sex ratios, survivorship, and growth of this species were investigated at 5 sites on the Pearl River in Mississippi over a 25-yr period. Estimates of age at maturity were 4.6 yrs for males and 9.1 yrs for females. Mean annual survivorship estimates for males, females, and juveniles were 0.88, 0.93, and 0.69, respectively. Maximum longevity estimates were 48.8 yrs for males and 76.4 yrs for females. Average longevity estimates were 8.5 yrs for males and 13.9 yrs for females. The sex ratio of captured turtles was male-biased before 2000 but unbiased after 2000. Realized population growth estimates indicated that 4 populations were stable over the 25-yr period and 1 population had declined. Population estimates and basking counts trended downward through time at most sites. Trapping success after 2000 for all sites combined declined by 77%, 45%, and 25% for juveniles, males, and females, respectively. Taken together, these data indicate that 1 population of G. oculifera has declined, 3 appear to be in the initial stages of decline, and 1 is relatively stable. Additional monitoring of these populations will be necessary to determine if these trends continue into the future.
机译：有效管理长寿物种需要从长期研究中获得的最佳人口统计和生命历史数据。密西西比州和路易斯安那州的珠江流域特有的环状锯齿背锯（Graptemys oculifera）是州和联邦政府都关心的一种物种。在25年的时间里，在密西西比州珠江的5个地点调查了该种群的大小，诱捕成功率，取暖数，性别比，存活率和生长。估计的成年年龄是男性为4.6岁，女性为9.1岁。男性，女性和青少年的平均年度生存估计分别为0.88、0.93和0.69。男性的最大寿命估计为48.8岁，女性为76.4岁。男性的平均寿命估计为8.5岁，女性为13.9岁。捕获的海龟的性别比在2000年前为男性有偏见，但在2000年之后为无偏见。实际的人口增长估计表明，在25年的时期内，有4种群稳定，而1种群减少了。在大多数地点，人口估计数和取暖计数随时间呈下降趋势。 2000年之后，所有地点的诱捕成功率分别下降了77％，45％和25％（少年，雄性和雌性）。综上所述，这些数据表明，有1个眼球菌种群下降了，有3个种群处于下降的初始阶段，有1个种群相对稳定。有必要对这些人群进行额外的监测，以确定这些趋势是否会持续到将来。

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