Among China’s bee-eaters (Meropidae), the blue-throated bee-eater ( Merops viridis ) and the blue-tailed bee-eater ( M. philippinus ) are both widely distributed and listed as second-class nationally protected species. However, their population statuses appear to contrast sharply. This study integrated online media reports, field surveys, and existing research to map their distributions, estimate population sizes, and analyze the ecological mechanisms behind their divergent conservation statuses. We found that the blue-tailed bee-eater maintains a large population (~44,000 individuals) concentrated in several key provinces (especially Yunnan), whereas the blue-throated bee-eater, though geographically more widespread, persists in numerous small, isolated groups totaling only about 2,000–4,000 individuals. This fragmented population structure creates a vicious cycle: small colonies are inherently vulnerable to local extinction, and when a colony is lost due to habitat degradation, there are no nearby source populations to recolonize the area, leading to a progressive, irreversible population decline. This paradox appears to stem largely from their divergent nesting strategies, although other factors such as predation and food availability may also play a role. Blue-tailed bee-eaters nest efficiently in vertical sandy banks, enabling high-density colonies, while blue-throated bee-eaters rely on flat sandy riverbanks, a habitat that is scarce, vulnerable to disturbance, and low in carrying capacity. Moreover, because blue-throated bee-eaters space their burrows at some distance from one another on flat terrain, supporting a colony of a given size requires a much larger area of suitable habitat than for blue-tailed bee-eaters, making large colonies inherently rare. Based on these findings, we recommend: for the blue-throated bee-eater, (1) upgrading it to Class I national protection; (2) creating engineered artificial sand piles to supplement nesting habitat; and (3) establishing a network of managed nesting sites to sustain its fragmented populations. This study underscores how subtle differences in resource use can drive vastly different population trajectories in closely related species, offering a model for targeted, evidence-based conservation.
Ke et al. (Mon,) studied this question.