Roost selection and ecology of Hipposideros pomona in China

Hipposideros pomona is a typical cave-dwelling bat (IUCN endangered), and its roost selection mechanism has not been studied. From January 2018 to December 2020, 135 potential roosts were investigated in mainland China. To understand the impact of cave microclimate, structure, surrounding and human disturbance on roost selection of H. pomona, 16 variables related to microclimate and roost characteristics were measured. The differences in environmental conditions in the roost of this species in different seasons were studied. The roost preferences of H. pomona were evaluated using independent-samples t-tests and chi-squared tests. The major environmental factors affecting the selection of roosts were determined by principal components analysis (PCA). The results were as follows: (1) H. pomona preferred free-hanging with a cluster spatial arrangement in small rooms deep in the caves. (2) H. pomona and other species of bats all tended to live in natural caves. However, compared to other bats, H. pomona preferred to roost in caves with relatively lower cave ceilings, more entrances, and farther from residential areas. Roosts of H. pomona were warmer and wetter with significantly lower levels of disturbance than those without H. pomona. (3) H. pomona preferred to hibernate in natural caves with little human disturbance and higher temperature and relative humidity. (4) Compared with nonbreeding roosts, breeding roosts of H. pomona had more areas covered by water and had a higher temperature and relative humidity. (5) The PCA analysis showed that microclimate factors, structure factors, and geographical factors were significant environmental factors for H. pomona roost selection.