Species abundance distribution and ecological niches of chigger mites on small mammals in Yunnan province, southwest China

The ecological niches and species abundance distributions of chigger mites were studied on small mammal hosts captured from 34 sites in Yunnan Province of southwest China between 2001 and 2015. Levins’ niche breadth and Colwell-Futuyma’s method were used to quantitatively evaluate host-specificity and similarity of host selection. Hierarchical analysis was used to illustrate niche overlap among mite species. Most mite species had a wide range of hosts with low host specificity. The niche overlaps between different mite species did not correlate with their taxonomic positions. Some mite species from different genera showed high niche overlaps and some others within the same genus showed low niche overlaps. Preston’s lognormal distribution model was used to fit the theoretical curve of species abundance distribution of mite community on Rattus tanezumi, the most dominant host species. The total expected mite species were then estimated roughly based on Preston’s method. The theoretical curve tendency of species abundance distribution indicated that the majority of mite species were rare species and that there were few dominant species with abundant individuals. The total expected number of mite species on R. tanezumi was estimated to be 224 species, and 92 species were likely missed in the sampling investigation.