Aim Recent breakthroughs in environmental niche models (ENMs) have substantially improved our insights in niche evolution. Assuming that closely related taxa have similar niches (i.e. niche conservatism), the combination of ENMs with phylogenetic information allows the reconstruction of ancestral niches. This reconstruction helps to identify the underlying speciation processes leading to diversification (i.e. ecological speciation under niche divergence and mutation-order speciation under niche conservatism). Here, we studied the niche evolution in white-eyes (the so-called 'great speciator') to understand their extraordinarily fast diversification rate, wide distribution and rather conserved phenotypes. In a broader perspective, unravelling niche evolution in white-eyes can shed light on how different niche properties such as climate, habitat or trophic level may contribute to diversification.