Department of Zoology and Entomology, University of Fort Hare, Alice, South Africa.
Centro de Investigação em Biodiversidade e Recursos Genéticos, CIBIO/InBio, Universidade do Porto, Vairão, Portugal.
Sci Rep. 2024 Nov 29;14(1):29701. doi: 10.1038/s41598-024-80619-4.
Animal activity patterns vary seasonally and between species, facilitating species coexistence. In Africa, however, factors affecting the activity of many small carnivores remain poorly understood, especially for congeneric and sympatric species whose similar sizes may lead to interspecific competition. Here, we investigated differences and variations in the activity patterns of two sympatric Viverridae species in a seasonal African landscape. We continuously radio-tracked 15 small-spotted genets (Genetta genetta) and five Cape genets (G. tigrina) over 24-h cycles throughout the year. We analysed the effects of season, sex, and interspecific interactions on circadian rhythms using multi-cosinor regression models. Both species maintained a nocturnal activity pattern year-round, decreasing activity significantly during the cold-dry season. This pattern aligns with the thermoregulatory hypothesis-especially for species with an elongated body like genets-suggesting decreased activity under extreme cold weather conditions to conserve energy. Females in both species were less active than males, possibly due to their smaller home ranges, especially during the cold-dry season. These effects were particularly pronounced in Cape genets, which primarily inhabit riverine forests. Female Cape genets adjusted their activity onset, possibly to minimize encounters with males, mostly during the hot-wet season when caring for their offspring. Small-spotted genets shifted their activity onset and peak in riverine forests-areas of potential contact with Cape genets-compared to areas without Cape genets. Overall, our study underscores the critical role of seasonal environmental changes and interspecific interactions in shaping the activity patterns of two carnivore species within a semi-arid Albany Thicket landscape.
动物的活动模式会随季节和物种而变化，从而促进物种共存。然而，在非洲，许多小型食肉动物的活动受哪些因素影响仍知之甚少，特别是对于那些体型相似的同属和同域物种，它们的相似体型可能导致种间竞争。在这里，我们研究了在季节性的非洲景观中两种同域灵猫科物种的活动模式差异和变化。我们全年通过 24 小时的连续无线电跟踪，对 15 只小斑灵猫（Genetta genetta）和 5 只海角灵猫（G. tigrina）进行了研究。我们使用多余弦回归模型分析了季节、性别和种间相互作用对昼夜节律的影响。两种物种全年都保持着夜行性的活动模式，在寒冷干燥的季节活动显著减少。这种模式与体温调节假说一致——特别是对于身体较长的物种，如灵猫——表明在极端寒冷的天气条件下，活动减少以节省能量。两种物种的雌性都比雄性不活跃，这可能是由于它们的家域较小，尤其是在寒冷干燥的季节。这些影响在主要栖息在河流森林中的海角灵猫中尤为明显。雌性海角灵猫调整了它们的活动开始时间，可能是为了尽量减少与雄性的相遇，尤其是在照顾幼崽的炎热潮湿季节。与没有海角灵猫的区域相比，小斑灵猫在河流森林——与海角灵猫有潜在接触的区域——改变了它们的活动开始时间和高峰期。总的来说，我们的研究强调了季节性环境变化和种间相互作用在塑造半干旱奥尔巴尼灌木丛景观中两种食肉动物活动模式方面的关键作用。
