Fig. 1 in Can biogeography help bumblebee conservation?

Fig. 1. Revising bumblebee species world-wide. The total bumblebee (indigenous) species richness is highest in Asia, especially in the Himalaya and Hengduan Mountains on the southern and eastern fringes of the Qinghai-Tibetan Plateau (Williams 1998, data updated). There are no indigenous bumblebees in sub-Saharan Africa, lowland India, or in Australia and New Zealand (and Antarctica). Species numbers peak in the region of Xining, Qinghai. Even when mapping such a globally well-sampled group as bumblebees, using a coarse-scale equal-area grid reduces species-area effects, reduces the effects of sampling heterogeneity (species-accumulation curves for these large grid cells are more nearly asymptotic than for many smaller grid cells), and smooths the effects of local habitat variation. The grid is based on intervals of 10° longitude, which are used to calculate graduated latitudinal intervals so as to provide equal-area cells (each cell has an area of approximately 611 000 km²). The colour scale has equal-frequency richness classes. Cylindrical orthomorphic equal-area projection (excluding Antarctica) with north at the top of the map. Lower left, inset: field-work sites sampled for bumblebees by the author 1971–2018 (red spots).