The serotine makes its appearance in public about sunset, apparently retiring early and flying again in the early morning.
The serotine and the Noctule are our two largest Bats, and in the early records they were very much confused.
The best known species (Tnia obtusata) has been found in the serotine, in the mouse-colored bat, and in Vespertilio lasiurus.
"late," 1590s, from French sérotine, from Latin serotinus "that which comes late; that which happens in the evening," from sero, adverb of serus "late" (see soiree). Also as a noun, a type of small, brown bat, from 1771. Related: serotinous, in botany (1880) "appearing later in the season than usual."