The importance of a holistic approach to the factors determining population abundances.

Research Highlight: Ogilvie, J. E., & CaraDonna, P. J. (2022). The shifting importance of abiotic and biotic factors across the life cycles of wild pollinators. Journal of Animal Ecology, 91, 2412-2423. https://doi.org/10.1111/1365-2656.13825. As global change and its multiple impacts continue to unfold across most of the planet, understanding how populations of wild species respond to changing conditions has become a major focus of ecological studies. Ogilvie and CaraDonna (Ogilvie & CaraDonna, 2022) focus on understanding how biotic and abiotic conditions affect bumblebee abundances. A major advance in their work is that, rather than focusing on a single measure of abundance at a particular life stage for each of the seven bumblebee species they survey (e.g. adult abundance), they focus on understanding the drivers of population abundance across the different stages of the species' life cycles. The authors specifically assess how three factors in particular, climate conditions, floral resource availability and previous life-stage abundances impact these abundances. A main finding in their study is that each of these three factors directly impacted a different life stage, showing that just focusing on a single life-stage would have resulted on a biased and incomplete picture of how abiotic and biotic factors affect bumblebee population dynamics. Studies like this one emphasize the need to focus on understanding the demographic mechanisms that determine population abundances.