Temporal changes in molar wear rate of a sika deer population under density-dependent food limitation
Temporal changes in molar wear rate of a sika deer population under density-dependent food limitation
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密度依赖性食物限制下梅花鹿种群磨牙磨损率的时间变化
DOI：
10.1111/jzo.12258
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
K.
中科院分区：
文献类型：
--
作者：
Takeshita;K.;Ishizaki;M.;Mitsuya;R.;Takahashi;H.;Yoshida;T.;Igota;H.;Ikeda;T.;Kubo;M. O. and Kaji;K.
长期以来，依赖密度的食物限制对有蹄类种群的磨损率以及反刍动物未磨损的磨牙大小及其性别差异的负面影响一直被研究。然而，这些研究是基于对来自不同地区或栖息地的种群的比较。如果在密度依赖的资源限制下，食物习性和生活史发生了巨大的变化，那么这种变化是否会导致磨牙磨损率的时间变化，以及在这种短暂但强烈的选择压力下，过度兴奋的程度是否会发生变化，这是非常有意义的。我们利用日本北海道中岛岛梅花鹿种群的长期监测数据，检验了磨牙磨损率的时间变化。与食物习性的改变相对应，摩尔磨损率的变化主要是因为当鹿以落叶为食时，二次摄取的土壤数量。在现存的梅花鹿种群中，摩尔磨损率是中岛岛第一次种群崩溃后最快的水平。然而，我们没有发现任何证据表明中岛鹿的性欲增加。增加磨牙耐久性的自然选择可能一直在Nakanoshima鹿身上发挥作用，但这种适应性变化尚未出现在统计上显著的水平。
Negative effects of density‐dependent food limitation on molar wear rate in ungulate populations, as well as unworn molar size and its sex differences in ruminants, have been studied for a long time. However, these studies were based on comparisons of populations from different districts or habitats. If drastic changes in food habits and life history occurred under density‐dependent resource limitation, it is of great interest whether this change caused temporal changes in molar wear rate, and whether the degree of hypsodonty changed under this short but intensive selective pressure. We examined the temporal change in molar wear rate using long‐term monitoring data of a sika deer (Cervus nipon) population on Nakanoshima Island, Hokkaido, Japan. Corresponding to the change in food habits, the molar wear rate changed mainly because of the amount of soil that was secondarily ingested when deer fed on fallen leaves. Molar wear rate was the fastest level after the first population crash on Nakanoshima Island among extant sika deer populations. Nevertheless, we did not find any evidence of increased hypsodonty in Nakanoshima deer. It is possible that natural selection for increased molar durability (hypsodonty) has been working on Nakanoshima deer, but the adaptive change has not yet appeared at a statistically significant level.