Philip H. Krutzsch

Observations on the Mexican Free-Tailed Bat, Tadarida mexicana

The Mexican free-tailed bat ( Tadarida mexicana ) ranges over much of western North America and is common and easily obtained. In spite of the wide distribution and ease of collection of these bats, data regarding their life-history are fragmentary. The observations presented here were gathered as part of a general study of the bats of southern California. Field work was done intermittently through most of the years 1938 to 1943 and in the summers (June to September) of 1946, 1948, 1949, and 1951. A planned life-history study was not made. However, a considerable amount of new information regarding this species has been recorded. Most of the observations here reported upon were made in San Diego County, California and unless otherwise noted all geographic localities are in this area. I wish to acknowledge the assistance given by Drs. Richard W. Neil, Carl Engler (1938–1943), and Keith L. Dixon (1946). Mexican free-tailed bats most often inhabit the Lower and Upper Sonoran Life Zones, however, they are not uncommon in the Transition Zone. In San Diego County these bats are most abundant at lower elevations, particularly on the western slopes of the mountains. Tadarida mexicana has a wide habitat tolerance and occurs in cultivated areas, on chaparral flats, on rocky hillsides, in open forests of yellow pine and black oak, and on juniper covered slopes of the eastern foothills. The free-tailed bats utilize a wide variety of diurnal roosting sites, selecting hiding places in both man-made and natural situations. These bats have been found roosting in the following man-made structures: wooden bridges, warehouses, barns, wooden and stucco houses, schools, behind signboards, milking sheds, attics, beneath tile roofs, and in open garages. Natural retreats are less often recorded, possibly because of the difficulty of locating such sites. Bats were found to frequent cracks and crevices …

Observations on the California Mastiff Bat

The mastiff bat is one of the largest and most impressive Chiroptera inhabiting North America. Eumops perotis californicus occurs most abundantly in southern California but its range also includes southern Arizona, western Texas and north-western Mexico. Much of our present knowledge of the life-history of this bat stems from work by H. W. Grinnell (1918), A. B. Howell (1920a, 6), A. B. Howell and L. Little (1924), P. H. Krutzsch (1943, 1945), and W. W. Dalquest (1946). The present paper synthesizes the foregoing citations and adds additional data. Many of the observations presented here were made in San Diego County, California and were gathered intermittently through most of the years 1935 to 1943 and in the summer months (June to September) of 1946, 1948, 1949, 1951, and 1953. I wish to acknowledge the assistance of Messrs. K. Dixon, C. Engler, J. R. Homesley, R. Neil, and A. C. Olson, Jr., all of whom accompanied me at one time or another in search of these bats. Thanks are also due Drs. S. B. Benson and Hildegard Howard for permission to examine material in their care. Eumops perotis calif ornicus is a species of the Lower and Upper Sonoran life zones and has been found in cultivated areas, in rocky places where chaparral and live oak intermingle, and in more arid, rocky situations where vegetation is sparse. Mastiff bats utilize a variety of roosting places: Von Blocker (1932) records one which was found hanging in a black acacia tree; Stephens (1906) lists a signboard and a tunnel as roosting sites; Howell (1920a, 6) records several old buildings (either stone or wood) as roosts; Krutzsch (1943, 1945) and Dalquest (1946) report having found them in crevices in rocks; and we have one taken from under a …

Ectoparasites from Some Species of Bats from Western North America

The ectoparasitic fauna of many species of bats has only begun to be known. A summary catalogue for the Chiroptera prepared by Stiles and Noland (Bul. Nat. Inst. of Health, 155: 603–742, 1931) presents a list of bats and their known parasites complete to the year 1930. G. M. Allen (bats, Harvard Univ. Press, 1939) reviewed much of the literature concerning parasites of bats and presented an excellent synthesis of this data. More recent data are to be found in monographs on various groups of arthropods (such as ticks, mites, fleas and flies) and in descriptions of new bat-inhabiting species. Accounts of a faunistic nature are poorly represented in the literature; therefore it is thought that the following notes, although admittedly incomplete, will indicate something of the ectoparasitic fauna for the 12 kinds of western North American bats considered. I wish to acknowledge the assistance of Dr. Furman of the Department of Entomology, University of California, Berkeley, who most kindly identified the parasites. The specimens reported upon were obtained at various localities in San Diego County, California in the months June, July, August, and September, 1946. The author was aided in their collection by Dr. Keith L. Dixon of Texas Agricultural and Mechanical College. It seems likely that most, and perhaps all, species of bats have ectoparasites of one sort or another. Certainly some individuals of all species that we collected were infested. Observations indicate that …

Some Normal Values of Peripheral Blood in the Vampire Bat

Data derived from study of peripheral blood samples of adult captive vampire bats, Desmodus rotundus , are here presented in order to provide some standard values for the blood of this important species; these include total red and white cell counts, differential white cell count, hematocrit and hemoglobin values. The red cell values are high as in other bats, and the total white cell population is characteristically low, being only 30%, however, of the value previously reported for the vampire. Hematocrit and hemoglobin values are higher than in mammals generally (related to the high red cell value) but approximate values reported in other bat species.

Additional Data on the Os Penis of Megachiroptera

Descriptions of the os penis of representative specimens of 22 species of Megachiroptera are presented. It is clear that differences between bacula from various species of a single genus are chiefly in minor details of outline and gross size, whereas, genera are distinguished by more profound differences in size and morphological characteristics of the baculum. It is recognized that the os penis is but one of several criteria for evaluating relationship and that the samples described are limited in number; therefore variations between individuals and in age are poorly understood. Nevertheless, strong intrageneric similarities exist and representative bacula of various genera differ distinctly. Such observations have been taken to indicate probable degree of relationship between groups but give little insight as to which group is specialized or primitive or representative of a basic evolutionary line. An arrangement of specimens according to similarities of bacular structure agrees favorably with one based on traditional skeletal and external characteristics.