Effects of elevated temperatures on the embryonic development and corpus luteum activity in the Japanese long-fingered bat, Miniopterus schreibersii fuliginosus.

Gravid female Japanese long-fingered bats were kept in captivity without hibernation at elevated temperatures (23-25 degrees C) in winter. The embryonic growth rate was accelerated and consequently parturition was advanced by a period equivalent to that of exclusion from hibernation as compared with that in the wild population. The corpus luteum became active, as indicated by an increase in the 'light' lutein cells in an experimental bat pregnant with a 15-mm embryo, but was less active (more 'dark' cells) in 2 hibernating control bats with an implanting blastocyst.