Weather conditions and population density individuals experience at birth influence their life‐history traits and thereby population dynamics. Early‐life individual growth is a key fitness‐related trait; however, how it is affected by such conditions at birth remains to be explored. Taking advantage of long‐term monitoring of three wild boar (Sus scrofa) populations living in contrasting ecological contexts, we assess how weather conditions (temperature and precipitation) and the number of removed individuals at birth influence early‐life growth rates. We found that the number of individuals removed before the early‐growth period had a positive effect on early‐life growth rate across sites. This might be interpreted as a density‐dependent response involving an increase in food availability per capita that favors faster growth. Alternatively, if the number of removed individuals increases with population density, this result might be attributable to decreasing litter sizes at high density, leading mothers to allocate more resources to individual offspring, which favors higher juvenile growth rates. Early‐life growth rates also increased with springtime temperature and decreasing precipitation. Thus, early‐life growth is expected to increase in response to warmer and drier springs, which should become more frequent in the future under current climate change. We found that conditions at birth explained very little among‐year variation in early‐life growth rates (i.e., weak cohort effects) and that within‐year variation in early‐life growth rates was more likely caused by strong individual differences.

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出生条件如何影响野猪的早期生长速度？

个人出生时的天气状况和人口密度会影响他们的生活史特征，从而影响人口动态。早期个体成长是与健身相关的关键特征。然而，它如何受到出生时这种状况的影响尚待探索。长期监测三种野猪（Sus scrofa））生活在不同生态环境中的人口，我们评估了天气条件（温度和降水）以及出生时被迁离的个体数量如何影响早年增长率。我们发现，在成长期之前被移走的个体数量对各个站点的早期生命增长率具有积极影响。这可能被解释为依赖密度的反应，其中包括人均粮食供应的增加，有利于更快的增长。或者，如果被移走的个体数量随着人口密度的增加而增加，则该结果可能归因于高密度下凋落物数量的减少，从而导致母亲将更多的资源分配给个体后代，这有利于提高幼体的生长速度。早期生长率也随着春季温度的升高和降水的减少而增加。因此，随着春季气候变暖和干旱，人们预期早期生命的增长将会增加，而在当前的气候变化下，这种情况在未来将会变得更加频繁。我们发现出生时的状况几乎不能解释早期生命增长率的年际变化（即，较弱的队列效应），而早期生命增长率的年内变化更可能是由强烈的个体差异引起的。