Birth-year and current-year influences on survival and recruitment rates of female Weddell seals
Birth-year and current-year influences on survival and recruitment rates of female Weddell seals
复制标题
出生年份和当年对雌性威德尔海豹存活率和招募率的影响
DOI：
10.1007/s10144-013-0379-0
复制
发表时间：
2013
影响因子：
1.7
通讯作者：
R. Garrott
中科院分区：
文献类型：
--
作者：
Glenn E. Stauffer;J. Rotella;R. Garrott
在长寿物种中，幼年生存率通常比成年生存率低且变化更大，对这种变化进行建模对于了解种群动态非常重要。青少年生存的变异性可能与出生或当年的影响有关，出生年份的影响可能是短暂的，持续的或中间的持续时间。我们使用多状态模型和收集的数据，从5,459已知年龄的雌性威德尔海豹（Leptonychotes weddellii Lesson）标记在埃里伯斯湾，南极洲从1980年至2007年，以评估潜在的出生年份对生存率的影响的持续时间和出生和当年对生存和招募率的影响的重要性。每个出生队列的存活率不同，与当年冬季海冰条件呈正相关。出生队列对生存率影响的估计持续时间为中期（6年），而不是短暂（2年）或永久性。从出生到6岁的估计存活率在队列之间从0.13（SE = 0.04）到0.42（SE = 0.06）不等，平均为0.25（SE = 0.02）。招募率（从预育种状态过渡到育种状态的概率）每年变化，但显然与出生年份条件无关。我们的研究结果提供的证据表明，出生和当年的条件相结合，以影响生存。虽然对于许多长寿的物种的出生或当年的条件对生存的影响进行了充分的研究，我们建议，建模生存率作为出生和当年的影响的函数，同时可以导致更好地理解生存和改进的随机模型项目人口动态。
In long-lived species, juvenile survival typically is lower and more variable than adult survival, and modeling such variation is important for understanding population dynamics. Variability in juvenile survival can be related to birth- or current-year influences, and the birth-year influences can be transient, persistent, or intermediate in duration. We used multi-state models and data collected from 5,459 known-aged prebreeder female Weddell seals (Leptonychotes weddellii Lesson) tagged in Erebus Bay, Antarctica from 1980–2007 to evaluate the duration of potential birth-year influences on survival rates and the importance of birth- and current-year influences on survival and recruitment rates. Survival rates differed for each birth cohort and were positively related to current-year winter sea-ice conditions. The estimated duration of birth-cohort effects on survival was intermediate (6 years) rather than transient (2 years) or permanent. Estimated survivorship from birth to 6 years of age varied among cohorts from 0.13 (SE = 0.04) to 0.42 (SE = 0.06), and averaged 0.25 (SE = 0.02). Recruitment rates (probability of transitioning from prebreeder to breeder state) varied annually but apparently were not related to birth-year conditions. Our results provide evidence that birth- and current-year conditions act in combination to influence survival. Although for many long-lived species the influences of either birth- or current-year conditions on survival are well-studied, we suggest that modeling survival rates as a function of birth- and current-year influences simultaneously could lead to better understanding of survival and improved stochastic models to project population dynamics.