Anthropogenic foods such as agricultural crops have potential to give large impacts on wildlife populations. However, few studies have addressed the impact of anthropogenic food consumption on the individual performance and then population of long‐lived mammals such as large herbivores. In this study, we investigated the effect of agricultural crop consumption on the physical characteristics and reproductive performances of sika deer (Cervus nippon) in central Japan. To investigate the relative dietary contribution of agricultural crops for each individual, we performed nitrogen stable isotope analysis of bone collagen. Our results suggest that nitrogen stable isotope ratios (δ¹⁵N) could be used as an index of the relative dietary contribution of agricultural crops. The δ¹⁵N value of agricultural crops was much higher than that of wild plants and that of bone collagen varied widely among individuals. Deer ≤4 yr old that were more likely to consume agricultural crops tended to be larger and have a higher reproductive rate. In contrast, body size and reproductive rate did not vary according to the relative dietary contribution of agricultural crops in individuals ≥5 yr old. These results indicate that consumption of anthropogenic foods can induce precocious maturity in younger individuals by improving their physical characteristics and reproductive performance. Agricultural crop consumption is therefore likely to be an important factor in the population dynamics of large herbivores living in agricultural landscapes.

中文翻译：

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农业作物的消费通过改善身体和生殖性能而诱发了鹿的早熟。

人为食物，例如农作物，有可能对野生动植物种群产生巨大影响。但是，很少有研究解决人为食物摄入量对个体性能以及诸如大型食草动物等长寿哺乳动物种群的影响。在这项研究中，我们调查了农作物消费对日本中部梅花鹿（Cervus nippon）的物理特性和生殖性能的影响。为了调查农作物对每个个体的相对饮食贡献，我们对骨胶原进行了氮稳定同位素分析。我们的研究结果表明，氮稳定同位素比率（δ ¹⁵ N）可以被用作农作物的相对贡献膳食的索引。δ农作物的¹⁵ N值远高于野生植物，而骨胶原的N值在个体之间差异很大。≤4岁的鹿更可能消费农作物，往往更大，繁殖率更高。相比之下，≥5岁的个体的体型和生殖率没有根据农作物的相对饮食贡献而变化。这些结果表明食用人为食物可以通过改善年轻人的身体特征和生殖能力来使其早熟。因此，农作物的消费很可能是生活在农业景观中的大型食草动物种群动态的重要因素。