IREC National Wildlife Research Institute (CSIC-UCLM-JCCM), Ciudad Real, Spain.
Oecologia. 2010 Oct;164(2):389-98. doi: 10.1007/s00442-010-1663-8. Epub 2010 May 28.
The influence of short- and long-term (cohort) effects of climate and density on the life-histories of ungulates in temperate regions may vary with latitude, habitat, and management practices, but the life-histories of ungulates in the Mediterranean region are less well known. This study examined the short- and long-term effects of rainfall and absolute density on hinds in two of the southernmost populations of red deer (Cervus elaphus hispanicus) in Europe. One population received supplementary forage. Unlike more northerly latitudes, where red deer hinds lose body mass in winter as a result of adverse weather, in the Spanish populations, hinds did not lose body mass. Hinds in the population that received supplementary forage were heavier and more likely to become pregnant than were the hinds in the unsupplemented population. The likelihood of pregnancy occurring was strongly influenced by hind body mass; the proportion of yearlings that became pregnant was consequently lower in the unsupplemented population than in the population that received supplementary forage. Cohort effects on hind body mass (negative for density and positive for rainfall at birth) and on the probability of pregnancy (negative for density at birth) were apparent only in the unsupplemented population, which implies that supplemental feeding may partially compensate for negative density-dependent factors during early growth, and that supplemented deer hinds may experience reduced selection pressures. These results reflect the particular seasonal variation in the abundance and quality of food in Mediterranean habitats. The delayed effects of climate and density at birth on adult hind body mass and the prevalence of pregnancy probably affects population dynamics and constitutes a mechanism by which cohort effects affect the population dynamics in Iberian red deer. The management of Iberian red deer populations should take into account cohort effects and supplemental feeding practices, which can buffer density- and climate-dependent effects and reduce natural selection pressures.
短时间和长时间（队列）的气候和密度对温带地区有蹄类动物生活史的影响可能因纬度、生境和管理实践而异，但地中海地区有蹄类动物的生活史知之甚少。本研究调查了降雨量和绝对密度对两个最南端的西班牙红鹿（ Cervus elaphus hispanicus ）种群中母鹿的短期和长期影响。一个种群接受了补充饲料。与更北的纬度不同，那里的红鹿母鹿由于恶劣的天气在冬季会失去体重，而在西班牙种群中，母鹿并没有失去体重。接受补充饲料的种群中的母鹿比未接受补充饲料的种群中的母鹿更重，更有可能怀孕。怀孕的可能性受到母鹿体重的强烈影响；因此，在未接受补充饲料的种群中，幼鹿怀孕的比例低于接受补充饲料的种群。只有在未接受补充饲料的种群中，母鹿的体重（出生时与密度呈负相关，与降雨量呈正相关）和怀孕的可能性（出生时与密度呈负相关）才出现队列效应，这意味着补充喂养可能在早期生长过程中部分补偿了负密度依赖因素，并且补充喂养的母鹿可能会经历较低的选择压力。这些结果反映了地中海生境中食物丰度和质量的特殊季节性变化。出生时气候和密度对成年母鹿体重和怀孕率的延迟影响可能会影响种群动态，并构成队列效应影响伊比利亚红鹿种群动态的机制。伊比利亚红鹿种群的管理应考虑到队列效应和补充喂养实践，这可以缓冲密度和气候相关的影响，并减少自然选择压力。
