Balčiauskas Linas, Balčiauskienė Laima
Nature Research Centre, Akademijos 2, 08412 Vilnius, Lithuania.
Animals (Basel). 2024 Jun 5;14(11):1686. doi: 10.3390/ani14111686.
The body condition index (BCI) is an indicator of both reproductive success and health in small mammals and might help to understand ecological roles of species. We analyzed BCI data from 28,567 individuals trapped in Lithuania between 1980 and 2023. We compared BCIs between species and examined differences in age groups, gender, and reproductive statuses within each species. Seven out of eighteen species had sample sizes with N < 100. In terms of species, we found that seven of the eight species with the highest average BCIs are granivores or omnivores, which can consume animal-based food at least seasonally. The two contrasting (decreasing or increasing) BCI patterns observed during ontogeny can be related to diet differences among juveniles, subadults, and adult animals. Our results demonstrate that reproductive stress has a negative impact on the BCI of adult females in all analyzed species and nearly all adult males. Although the animals with extremely low BCI consisted mostly of shrews, for the first time we found 23 common and pygmy shrews exhibiting the Chitty effect, i.e., a very high body mass resulting in a BCI > 5.0. This is the first multi-species approach of body condition at middle latitudes. The results increase our understanding of how changing environmental conditions are affecting small mammals.
身体状况指数（BCI）是小型哺乳动物繁殖成功率和健康状况的一个指标，可能有助于理解物种的生态作用。我们分析了1980年至2023年期间在立陶宛捕获的28567只个体的BCI数据。我们比较了不同物种之间的BCI，并研究了每个物种内不同年龄组、性别和繁殖状态的差异。18个物种中有7个物种的样本量N < 100。在物种方面，我们发现平均BCI最高的8个物种中有7个是食谷动物或杂食动物，它们至少在季节性时可以食用动物性食物。在个体发育过程中观察到的两种相反（下降或上升）的BCI模式可能与幼年、亚成年和成年动物的饮食差异有关。我们的结果表明，繁殖压力对所有分析物种的成年雌性和几乎所有成年雄性的BCI都有负面影响。尽管BCI极低的动物大多是鼩鼱，但我们首次发现23只普通鼩鼱和侏儒鼩鼱表现出奇特效应，即体重极高导致BCI > 5.0。这是首次在中纬度地区采用多物种方法研究身体状况。这些结果增进了我们对不断变化的环境条件如何影响小型哺乳动物的理解。
