Roosting ecology of endangered plant-roosting bats on Okinawa Island: Implications for bat-friendly forestry practices.

Roosting information is crucial to guiding bat conservation and bat-friendly forestry practices. The Ryukyu tube-nosed bat (Endangered) and Yanbaru whiskered bat (Critically Endangered) are forest-dwelling bats endemic to the central Ryukyu Archipelago, Japan. Despite their threatened status, little is known about the roosting ecology of these species and the characteristics of natural maternity roosts are unknown. To inform sustainable forestry practices and conservation management, we radio-tracked day roosts of both species in the subtropical forests of Okinawa's Kunigami Village District. We compared roost and roost site characteristics statistically between nonmaternity roosts (males or nonreproductive females), maternity roosts, and all roosts. Generalized linear models were used to investigate roost site selection by irrespective of sex and age class. Lastly, we compiled data on phenology from this and prior studies. Nonreproductive roosted alone and primarily in understory foliage. maternity roosts were limited to stands >50 years old, and ~60% were in foliage. roosted almost entirely in cavities along gulch bottoms and only in stands >70 years old (~1/3 of Kunigami's total forest area). maternity roosts were higher (4.3 ± 0.6 m) than conspecific nonmaternity roosts (2.3 ± 0.5 m;  < .001) and roosts (2.7 ± 0.5 m; not significant). Model results were inconclusive. Both species appear to be obligate plant roosters throughout their life cycle, but the less flexible roosting preferences of may explain its striking rarity. To conserve these threatened bats, we recommend the following forestry practices: (a) reduce clearing of understory vegetation, (b) refrain from removing trees along streams, (c) promote greater tree cavity densities by protecting old-growth forests and retaining snags, and (d) refrain from removing trees or understory between April and July, while bats are pupping.