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Digitized by the Internet Archivein 2012 with funding fromRoyal Ontario Museumhttp://archive.org/details/leafletr10royaROYAL ONTARIO MUSEUM OF ZOOLOGYTORONTOLEAFLET NO. 10BATS*The Silver-haired BatFROM early times bats havebeen regarded with fear anddislike. So many tales havebeen told of their evil characterthat even to-day people are horri-fied by these harmless creatures.When we study bats, we find thatmost of the stories told about themare untrue, and that in general theyare interesting and useful animals,well equipped to fill their particularniche in the animal kingdom.The bat is the only mammalwhich can really fly. There are afew others like the flying squirreland the flying lemur which have theskin extended on either side of thebod}\ enabling them to glide or plane for some distance, but this isnot true flight. Man too can fly, but he needs the help of a machine. Sothe bat is the only mammal that has learned to use its body for flying upand down, or turning sharply in the air, just as birds do. But bats do notresemble birds at all, except in their ability to fly. Being mammals, theyneither lay eggs nor build nests. Young bats are born alive, and are fedfor a time on milk produced by the mother. Their warm-blooded bodies,like those of most other mammals, are covered with short, fine hair.The bat's wing is quite different from that of a bird. The bird'swing is made up of many overlapping feathers, while the wing of a batconsists of a single piece of skin, stretched between the front and hindlegs. The support for this airtight wing is provided by the long bones ofthe arm and hand. The bones of the front limb of a bat correspond tothose of other mammals, but they are much longer in proportion to therest of the body. The bones of the four fingers especially are enormouslyelongated, as will be seen from the accompanying illustration. The thumbReprinted from T IK SCHOOL February, L937. /TV y^\W))is the only bone of the hand which is not enlarged. It has a claw on it andis not attached to the wing membrane.The hind leg of a bat is not altered as the front leg is. It is quitesmall really, and is not of much use in walking. A bat can only shufflealong a flat surface, for both pairs of legs are attached to the big wingmembrane. The toes of the hind foot have claws on them, by means ofwhich the bat hangs upside down when roosting, as you will see in theillustration. In Ontario bats, the wing membrane is also continued acrossfrom the hind legs to the tail. When the tail and legs are drawn up underthe body, a useful pouch is formed.The flight of a bat is quick and jerky. This jerkiness is the resultof a bat's way of hunting. Each insect is chased separately, and that iswhy a bat flies in such a zig-zag fashion, for it is pursuing first one insect,then another. Bats fly very silently, even through thick woods. For morethan a century naturalists have known of their ability to avoid obstacles.Experiments with blinded bats prove that they can make their way throughcrossing lines of fine silk without becoming entangled. Bats have a moredelicate sense of feeling than other animals, for they are aware of objectswithout either seeing or touching them. A captive bat will not try to flyout through a closed window as a bird will, for it is aware of the glassas a solid object without ever bumping up against it.There are two great groups of bats, the Big Bats which feed mostlyon fruit, and the Little Bats which live on insects. The large, fruit-eating bats are found in Australia and the tropical regions of Asia andAfrica. Some of these, known as "flying foxes", have a wing spread offive feet. The little bats are all insect eaters, except the dreaded vampirebats of Central and South America and the West Indies. The vampirebats feed only on blood. They puncture the skin of a sleeping animalwith their sharp front teeth so skilfully that the sleeper does not wake up,and then they lap up the blood, as it flows from the wound. All NorthAmerican bats feed only on insects. For this reason they are beneficial,as they keep down the numbers of night-flying insects. Because batshave large stomachs and eat very rapidly, they consume enormous num-bers of insects.Many bats prefer to roost with large numbers of their own kind.Sometimes they choose roosting quarters in homes. The little brown batis the only one in Ontario which has this habit. Typical roosting placesare attics, walls, chimneys, the space behind shutters and similar situationswhich are undisturbed and to which access is afforded by small openings.The disagreeable odour quickly associated with a bat roost, the noise madeby the bats, and the general aversion people have to them, make theirpresence in homes objectionable.The best way to prevent bats from roosting in homes is to board overor plug up all the openings by which they enter. Where there are a num-ber of openings, all hut one or two can he closed in the daytime. Aftera day or two, when the hats have learned to use the remaining exits, theseshould be closed several hours after dusk, after all the hats have left. Asthey can squeeze through openings less than an inch in width, even smallholes should be closed. The strong odour clinging to a hat roost is veryattractive to their kind, and hats will try to return to a roost, if any open-ings to it can be found.If it is impossible to seal the openings to the roost, but is possible toreach it, a repellent such as naphthalene flakes may be used. The gasgiven off by these flakes is very objectionable to bats, although harmlessto humans. Two to five pounds are usually required to drive out a colony.The flakes should be liberally thrown around the roost. A second applica-tion is sometimes required, if the bats return after the naphthalene fumeshave disappeared.Fumigation may be necessary as a last resort if the colony cannot bedislodged in any other way. The hydrocyanic acid gas usually employedis extremely poisonous to humans, and the work should be carried outonly by an experienced operator.Much of the fear and dislike of bats is due to ignorance, some of itverging on superstition. One of the most widespread fallacies is that batswill become entangled in women's hair. A bat finding itself in a woman'shair would be as ill at ease as the owner of the hair. Their ability toavoid flying into objects injurious to them can be counted on to keep themout of a head of hair. The popular saying "as blind as a bat" is also false.Bats have small but well-developed eyes, and can distinguish light anddarkness and moving objects at least. Even when blinded, their sense ofdirection is still good, and they can locate flying insects and avoid obstacles.Bats are often accused of harbouring insect pests. Colony-dwellingbats are troubled by ticks and fleas, sometimes in great numbers, but noneof these are the same as those affecting man. The bat is host to a "batbug", which in appearance resembles the human bed bug of notoriousreputation. These bugs are quite different, however, and bat bugs willnot continue to infest human dwellings if the bats are eradicated.There is still much to be learned about bats. One of the most inter-esting problems concerns their migration. That they do migrate is indi-cated by the following facts. In the north, bats disappear in the fall andappear again in the late spring. Bats have been killed at lighthouses incompany with migrating birds. There are scattered records of numbersof bats seen in flight in late autumn, and of bats coming to rest on ships atsea. Red and hoary bats are known to occur in Bermuda during the wintermonths, and to disappear during the summer. Of Ontario bats the red,hoary, and silver-haired are known to migrate. Some of the large brownhats migrate, but others hibernate, and it is not unusual in southernOntario for big brown bats to be seen flying about in mid-winter, after aperiod of unusually mild weather. Very little is known definitely aboutbat migrations, and information about the winter occurrence of batswould be of much interest to the Museum.Six species of bats are common in Ontario : the big brown bat, twospecies of little brown bats, the red bat, the silver-haired bat, and the hoarybat. Three rare species, the pipistrelle, the least brown bat, and the eve-ning bat, have also been recorded in southern Ontario.The common names of our native bats are all based on the coatcolour. The big brown and the little brown bats are generally woodbrown, sometimes with a bronzed cast to the coat. The fur of the redbat varies from yellow to red, and is often very beautiful. The silver-haired bat is dark brown or black, with silvery-white tips to the hairs,which give the coat the appearance of being frosted.- The hoary bat isyellowish gray or brown with white tips to the hairs on the back.The hoary bat is the largest of our Ontario species, with a wingspreadof fifteen inches in the adult. The little brown bat is the smallest, witha wing spread of nine and a half inches. The wing spread of the silver-haired bat is eleven inches, that of the red bat and the big brown bat abouttwelve inches. The length of body and tail together varies from threeand one-half inches in the little brown bats to five inches in the hoary bat.The little brown bat is a typical colony dwelling bat. The big brownbat is also found roosting in homes, behind blinds or shutters, or in attics,but not in numbers. The red, hoary and silver-haired bats are moresolitary, forest-dwelling types.Bats appear at regular times in the evening, and it is possible toidentify them on the wing from the time of their appearance and fromtheir manner of flight. The little brown bats appear early in the evening,and their small size and quick dodging flight are characteristic. Thesilver-haired bat and the red bat also appear rather early. The big brownbat comes out later, and the hoary bat is the last one to be seen.The distribution of bats over the whole of Ontario is not well known.Generally speaking, they are more common in the southern half of Ontariothan in the northern part. The hoary bat is the rarest, the common littlebrown bat the most abundant. The red, hoary, and silver-haired bats areusually seen in forested sections, patrolling up and down streams andrivers, or circling around lakes. The little brown and big brown bats aremore often seen around cities.The Museum would appreciate any information on the distributionof bats in Ontario, records of their appearance in spring and disappear-ance in fall, dates when young bats are first seen, and evidence of migra-tion or hibernation. Specimens are always welcome. Enquiries aboutbats are invited. p. m. o.

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