Sibaja Leyton Malena, Lattorff H Michael G, Kiatoko Nkoba, Requier Fabrice
Université Paris-Saclay, CNRS, IRD, UMR Évolution, Génomes, Comportement et Écologie, Gif-sur-Yvette, France; International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya.
University of KwaZulu-Natal, School of Life Sciences, Westville Campus, Durban, South Africa.
J Environ Manage. 2025 Feb;374:123879. doi: 10.1016/j.jenvman.2024.123879. Epub 2025 Jan 6.
In recent decades, worldwide concerns about the health of honey bees motivated the development of surveys to monitor the colony losses, of which Sub-Saharan Africa has had limited representation. In the context of climate change, understanding how climate affects colony losses has become fundamental, yet literature on this subject is scarce. For the first time, we conducted a survey to estimate the livestock decrease of honey bee colonies in Kenya for the year 2021-2022 to explore the effects of environmental conditions, such as temperature and precipitation, on livestock decrease. We define "livestock decrease" from the beekeeper's perspective, including dead colonies but also, in the specific context of the tropics, the colonies that absconded from the apiary. A total of 589 beekeepers from a variety of areas participated in the survey. Kenyan beekeepers had an average of 36.6% livestock decrease in 2021-2022, with higher decreases during the dry and hot (31.9%) than during the wet and cold season (20.2%). We found that livestock decreases were more important with temperature for both dry and hot and wet and cold seasons. Interestingly, we found that precipitation mitigated temperature effects on livestock decrease for both seasons. Finally, we found that beekeepers practicing water supplementation had up to 10% less livestock decrease during the dry and hot season than those that did not, suggesting it to be a relevant adaptive strategy to mitigate livestock decrease. It is worth noting that beekeepers can renew their stock by trapping swarms, yet this represents a cost in time and baiting materials. Based on climate change projections, we predicted that annual and seasonal livestock decrease would remain in the same range at horizon 2050 and horizon 2100. These results pinpoint difficulties in maintaining livestock for beekeepers in Kenya and provide clues for strategies to pursue in the context of climate change.
近几十年来,全球对蜜蜂健康的关注推动了监测蜂群损失的调查的开展,而撒哈拉以南非洲在这些调查中的代表性有限。在气候变化的背景下,了解气候如何影响蜂群损失已变得至关重要,但关于这一主题的文献却很匮乏。我们首次开展了一项调查,以估算2021 - 2022年肯尼亚蜜蜂蜂群数量的减少情况,探讨温度和降水等环境条件对蜂群数量减少的影响。我们从养蜂人的角度定义“蜂群数量减少”,包括死亡的蜂群,在热带地区的特定背景下,还包括逃离蜂箱的蜂群。来自不同地区的589名养蜂人参与了此次调查。2021 - 2022年,肯尼亚养蜂人的蜂群平均减少了36.6%,干旱炎热季节(31.9%)的减少幅度高于湿冷季节(20.2%)。我们发现,无论是干旱炎热季节还是湿冷季节,蜂群数量减少都与温度更为相关。有趣的是,我们发现降水在两个季节都减轻了温度对蜂群数量减少的影响。最后,我们发现,在干旱炎热季节,进行水分补充的养蜂人的蜂群数量减少比未进行水分补充的养蜂人少多达10%,这表明水分补充是减轻蜂群数量减少的一种相关适应策略。值得注意的是,养蜂人可以通过诱捕蜂群来补充蜂群数量,但这需要花费时间和诱饵材料成本。基于气候变化预测,我们预计到2050年和2100年,年度和季节性的蜂群数量减少仍将保持在相同范围内。这些结果指出了肯尼亚养蜂人在维持蜂群数量方面面临的困难,并为在气候变化背景下应采取的策略提供了线索。