expanse of the outstretched wings of the noctule reaches 13 or 14 inches, and as it flies before the light has faded, often before the swifts have vanished, it is a conspicuous object against the evening sky.
Donovan, in 1820, said of the noctule that it "is of a colour far less dismal than that of the common bat," and though the pelage of the pipistrelle is hardly dismal, the fur of the noctule is a beautiful ruddy brown, almost golden at certain seasons. The question of the seasonal and age variation in colour of mammals is not fully investigated, and the researches in bats have yielded little result. Barrett-Hamilton found no evidence of change in the noctule, but thought it probable that the colour was richest just before hibernation—that is, after the season's activity and constant feeding. Old males, I have always found, are far more golden than immature bats. These aged males, at the height of the breeding season, are wonderfully sleek and glossy. Donovan's picture of the noctule was, I hope, drawn from memory; the colour is curious, and it possesses a leaf nose not unlike a vampire, whilst the tragus is depicted as long and pointed instead of short and rounded. Bingley's plate, published in 1809, is far better. The Rev. W. Bingley is little known as an authority on British animals, but of mammals in particular he was a careful observer, deserving a better reputation than he enjoys. At last we can boast good figures of our British bats, for Mr. Thorburn's lifelike pictures can hardly be improved.
The noctule emerges from its winter slumbers in March or April, and it is usually the beginning of the latter month before it is much in evidence; it has been seen flying in February and exceptionally earlier. In September, if the weather is suitable, it is abundant until the end of the month, and often is abroad regularly in the early part of October, but a November noctule is rare.
