| OCR Text |
Show 7 SI' j 1 P i I 1 I M F,! i t S Q . ; . - 1 V-jo ... Science y . The cmon Bat C: iV: Discovers Many IM ew and , Who Help Men j 1 5 s , Do5.,stHyisKTui i xv" Curious Facts About Enemies. ( g .s " ' A lfV, , v These Strange Flying i .?:' A, X?W' lif !4 and Proves Their .-:: S4 S .-Mosqmt-s and - ' f .iA Umbrella . V V V W yY. J Af-llAir Pcfc 4 ' 7 " ::v?s Duringa v-i, r vT iv. iltlier rests . , v f -' ' ' Rainstorm. " -i.' Folds ' 'f J 'Jl Himself Up t f " - " S 'x 5 Waterproof "l ' SUf Wings, Hangs ' " -' Himself Up . i ' , xXW- v iif by His Hind 5 1 r ; "V 'i- Legs and Goes V i , ' ' , ; CHC Comfortably , J - ( ! " to Sleep i ( - . ? $fl It Ram. By W. H. Ballou, D. Sc. PERHAPS it is because of the existence of one lone mammal that can fly that " you and I exist. The bat, mind you, probably evolved prior to all other mammals, mam-mals, and it was his province to reduce in the air the dominant, swarming insect tribes which in those early times easily owned the earth after nine million years, of continuous breeding on a vast scale. His associate in the good work of insect destruction, evolving not long after him, was the ant-eater. The function of the latter was to clear the ground of a class of insects as deadly as those which had wings. First birds were not insect eaters. They were car-nivora, car-nivora, and probably fed on the fat, insect-eating insect-eating bats, preventing them, in turn, from becoming too dominant. Thus all nature checks growth of too dominant animals and plants, and makes for an average of species. Nor will man himself permit any particular race or nation of men to become too dominant. domi-nant. Hence there have been wars' between men, somewhere on earth, if not over most of it, ever since primitive man was evolved. The bats have strange habits of living. Thousand of them mass together in caves and attics, or fill up a hollow tree to its capacity. It is doubtful if bats could perform per-form their whole province in nature, that of vast insect extermination if life were not conducted in a manner, productive of immense im-mense progeny. , Three new scientific works on bats have just been issued from the laboratories of as man' institutions. These comprise "The American Museum Congo Expedition Collection Col-lection of Rats." by J. A. Allen, Herbert Lang and James P. Chapin; "A Synopsis of the Bats of California." by Hilda Wood Grinnell. University of California Museum : and "The families and Tenera ot bats, by Gerrit S. Miller, Jr., United States National Na-tional Museum. From them and other contributions con-tributions the present observations are taken. Dr. "W. K. Gregory refers the origin of bats back beyond the beginning of the Age. of Mammals: "The group was very highly specialized as far back as the Eocene . . . and probably acquired many of their ordinal or-dinal characters before the known Terfiary record began. There can be little doubt that, they descended from late Mesozoic or early Tertiary insect ivora." Linnaeus, who placed the bats with the Primates m I108, from which they were separated by Gray in 1821, was not so far out of the way. Gregory shows that the ancestors were tree and elephant shrews, with large hands and feet, whieh lived in trees. These were followed by the Cobego, an iencst eater. Because he was of the original flapper with near wings some one named him the tl flying lemnr," although he was not a lemur. The third stage of evolution was the bats proper, with small hands and feet, followed by the Primates proper, comprising lemurs, monkeys, apes and man. Gray divided the bats into two classes, those which from the beginning have ' lived upon insects and those which descended from them, the fruit eaters. Of the latter, the largest species extant is the so-called "flying fox," of Malay, which has a spread of wings of five feet or more. Of the former class, or rather, out of it, is the South American vam- pire bat. which lives on blood only, and which, when confronted with a choice, as between a mule and the man on its back, lights on the mule and sucks its blood until dispossessed. Lang and Chapin say: "South America also has fishing bats. In Africa, where there are large herds of game, there are no vampire bats. In the Neotropical region, where there are numbers of fruits in the large Equatorial forests, there are no fruit eating bats. The fruit eaters command attention by their great, flights, continuing for weeks across the African country. Their noisy voices cannot be compared with the faint squeaks of even a dozen hawk bats, though they may appear regularly on the village square. By infesting double-roofed houses or uninhabited rooms they make themselves a nuisance, since the smell becomes unbearable unbear-able in the moist atmosphere. ' ' TVhen they emerge at night, each bat hunts Blainville's'Eat, Showing the Hair &ff That Give the Animal Its Sixth ll'WC'S.k Sense, Enabling It to Avoid Ob- , Ai K-$ iects It Cannot See. h ' 1 A separately. The African insect hats, common in both zones, show preference for neither rain forest nor bushveldt, but for localities where are the types of insects they like best. Fruit bats are more common in African regions covered by rain forests, where fruit ripens throughout the year. Since fruits are not always equally plentiful, they have to shift continually, having nowhere established roosts. It is within their powers of flight to travel across the country between 5 degrees north and 5 degrees south of the Equator. Since travellers note the occurrence of several sev-eral species throughout this range, migration is the only possible solution, otherwise they would starve if they remained in one region continuously. "The digestion of fruit bats is so rapid that they must travel afar and often to keep supplied. sup-plied. They cause no devastation to plantations, planta-tions, as the natives do not cultivate indigenous fruits, and plantains and bananas are picked before they ripen. The natives c eat bats because of their large, juicy lumps of fat in and about the abdomen, raiding cave's which may contain colonies of thousands, made up habitually of a single species." It is evident from the final statement that bats, however miscellaneous in their breeding, breed-ing, do not cross species, but stick to their individuality. Anderson discloses that a single species, Rhinopoma microphyllum, inhabited the pyramids for 3,000 years, "without showing any perceptible changes." Although Spallanzani has shown that insect in-sect eating bats will not strike objects in flight if blinded, Lang and Chapin find no such delicate sense of touch in fruit bats. Fruit eating is evidently a specialization, a breaking away from the ancestral insect eating eat-ing types. Some insect eaters must have found their food in the larvae of insects inside of fruit. In digging out the insects, they must have acquired a taste for fruit. Some individuals were perhaps forced to Ireat Bat Roost Erected by Dr. C. A. K. Campbell, Camp-bell, at San Antonio, Tex., to Encourage the Bats to Stay and Fight Mosquitoes. eat the fruit, when no larvae were found, or perhaps came to prefer fruit to insects. Result Re-sult : the modification of feeding habits caused a gradual modification of structure, . and many species of fruit eating bats arose. I find no evidence recorded, however, that any of these bats reject fruits having insects in-sects inside or insect larvae. That bats were food for primitive men is indicated by Miss Grinnell in her work on bats of California: "The bat had become, master of the air long before man walked upright. The rocky refuge revealed to the cave" man the little upside down bat clinging cling-ing to the roof of his cavern. One bat takes its food off the ground, since it brings to its roost wingless Jerusalem crickets, cither at- tracted by the noise the insect makes in crawling or the air currents made by such movements. Bats seeking to escape from a room do not dash against a window pane as birds do. Approach to such obstacles is detected by the ' ' ! V svi ,-.-. S sirs 1 . ' "TlnterestinE Pictures of the Hump-Nosed Bat. X. Sound Asleep a Awakened. 3- Ready for Flight. Copyright. 1918. .by the Star Company. Great Britain Rights Reserved. reflex currents of air. Three species only of bats are known to be common all over North America, the silver-haired, the hoary and the red bat. Each species is migratory. Merriam classifies American bats, excepting those the habits of which have been modified by pi-ox-imity to humans, as cave dwelling or tree dwelling, according to the places in which they spend the day. Hoary bats migrate at) least as far south as the Bermudas, crossing 600 miles of ocean, or as Miller thinks, fly from Cape Cod by the 700-mile route. "" Dr. W. D. Matthew points out that bats j are easily able to cross ocean barriers, because be-cause of the plain fact that they have done ' i so frequently. I have found red bats in ever- ' green trees in Winter and eever in caves, but Seton asserts that while they roost in trees ; in Manitoba, they gather in vast numbers in 1 caves of the South for hibernation. Mearns records all day migratory flights of red bats, each flock of one sex. It is not generally gen-erally realized that bats possess powers of flight superior to those of many birds. This j may be inferred from the fact that a red bat has been known to catch flies in the air, ! while burdened vrith young that, together weighed more than she did. Most California bats catch and devour prey on the wing. They bite off and reject the hard parts of insects, and hence it is difficult to identify the species of insects in the stomach. One species brings the larger insects to itsroost and devours them while hanging head down. At least two species of British , bats, according to Barrett-Hamilton, hold the tail , curved beneath them in flight, thrusting struggling insects in the sac formed until they get a firm grip upon them. The . tail curving must be due to an unusually far back center of gravity. In the Autumn bats have become very fat, ready for migration or hibernation. Even the bats on the wing all of the year rely on this stored fat to balance a scarcity of insects. Buildings are readily cleared of colonies of bats by boarding up their entrance places at night when they are on the wing. Bats are as valuable to humans as insec- tivorous birds. They are especially important in keeping in check nocturnal insects, especially disease f carriers. Campbell at Mitchell's Lake, Texas, found that 90 per cent of the food of bate there con-sisted con-sisted of malarial carrier mosquitoes. He advocated ad-vocated erecting roosts in all parts of the country where mosquitoes are pestiferous. San Antonio responded by erecting a roost and protecting bats by law. The Hudson Bay Company, however, protected bats as far back as 1839, to enable them to exterminate the insect in-sect Dermestes, which abounded in fur establishments. estab-lishments. If a bat has his cheek provided with sharp cusp teeth for piercing beetles, etc., it is an insect eater. If it has modified front teeth for piercing skins of animals, it is a blood ;uoker or vampire. If the crowns of the cheek teeth are smooth and grooved, it is a fruit eater. Some species of bats exist at high altitudes. alti-tudes. Grinnell found the Tejon bat at 8.500 feet above the sea in the San Bernardino Mountains and the High Sierra Bat at 10.350 feet. Bats are powerful swimmers. They have to be. Muscallonge, pickerel, salmon, etc., capture cap-ture many of them as they come down to the surface for insects. They are difficult to shoot because of swift, erratic flight; perhaps also having some ability to dodge, shot when warned by an approaching air wave. Most female bats have two mammae. The females of the genus Nycteris have four mammae (breasts). Bats with two mammae may produce pro-duce one or two young; with four mammae, up to four young. r |
