James B. Cope

Summer Habitat and Ecology of the Endangered Indiana Bat, Myotis sodalis

A nursery population of M. sodalis was discovered in Indiana and studied for 2 years. The nursery roost was located under the loose bark of a dead tree. Sometimes the bats temporarily moved to bark crevices of a living shagbark hickory tree. Weather strongly affected roost microclimate. The nursery tree was unshaded and received maximal solar warmth during clear, mild or hot weather, whereas temperature at the shaded alternate tree was more stable during spring and autumn cold. The nursery population consisted of adult females and young, and few males were netted in local foraging areas. Each female bore a single young and these incurred eight percent mortality between birth and weaning. Social behaviors included “checking,” mothers carrying young to an apparently warmer portion of the roost tree, and apparent mother-young foraging flights as the young became volant. Unusually cool weather in summer 1974 slowed the growth of young; this delayed recruitment of flying young more than 2 weeks and the completion of migration by 3 weeks. The delay exposed some bats to freezing weather at the nursery and may have affected mortality, autumn mating, or fat storage for winter. No problems were evident during the favorable summer of 1975. Foraging habitat included the foliage of riparian and floodplain trees, and the 50 bats used a 0.82 kilometer (km) linear strip of creek. Similar habitat was used by two other populations in Ohio. Before young were volant, adults fed only about riparian trees; when young began to fly, feeding extended to solitary trees and forest edge on the floodplain. This reduced foraging density from 17 to 11 bats per hectare (ha). Suitable foraging habitat occurs over much of the eastern United States, and use of local trees for nurseries makes a large summer distribution possible. Humans also value floodplain habitat, and a land use conflict exists between the two species.

Survival Rates of the Endangered Indiana Bat, Myotis sodalis

Rates of survival of Myotis sodalis are calculated from recaptures of bats marked in cohorts of unknown age. Such data can be misleading, so the proper types ot interpretation are identified. Survival rates are high for 10 years after marking in females and 6 years in males. Females can live as long as 14.8 years and males as long as 13.5 years. Survival of the species is good in undisturbed environments, and endangerment results from loss of habitat.

Distribution and Status of the Chiroptera of Indiana

The following species are recorded for the State: Myotis lucifugus, M. austroriparius, M. grisescens, M. keenii, M. sodalis, Lasionycteris noctivagans, Pipistrellus subflavus, Eptesicus fuscus, Lasiurus borealis, L. cinereus, Nycticeius humeralis, Plecotus rafinesquii. Of these, Myotis austroriparius, M. grisescens, and Plecotus rafinesquii are rare and occur locally. Data on known breeding colony locations are mapped by counties. A key to adult bats is included. Among native Indiana mammals, the least known are the Chiroptera. Bats are extremely difficult to study, and since they are of less economic importance than game animals our knowledge of bats has lagged far behind that of many other species. Early Indiana naturalists and mammalogists, with the exception of Walter L. Hahn, worked little with bats. Many old literature references are to specimens not preserved or to collected material no longer extant; many identifications (especially in the genus Myotis) cannot be verified. More recently, mammalogists have taken a renewed interest in these fascinating mammals. The availability of Japanese mist nets for collecting has greatly facilitated field work. Also, more research funds have become available since several insectivorous species of bats in the United States have been implicated in diseases harmful to man, such as rabies, histoplasmosis, and encephalitis. Our own interests date from the late 1940s, and when we obtained bat-banding permits in the fall of 1951, field work began in earnest. Cope worked under National Science Foundation Grant No. 9321 from 1958 to 1961. A five-year study of the mammals of Indiana, supported by the Agricultural Experiment Station, Purdue University, was begun by Mumford in 1958. Our studies are continuing, but have already revealed much new data concerning the 12 species of bats known from the State. This is the first attempt since Lyon (1936) to bring distribution and population data up to date. Common names used in this report are from Hall and Kelson (1959). We follow Handley (1959) with regard to the taxonomy of the big-eared bat. The synonymy for each species applies only to names used by authors in reference to Indiana. In the following species accounts, information under History refers to the literature prior to and including Lyons Mammals of Indiana in 1936, after which a decided break in data existed until our own work began. Acknowledgments.-We thank the National Science Foundation and Purdue University for financial assistance in carrying out the later phases of our research. Among the many persons who provided considerable aid in the field or supplied field notes were Ted Brown, Jack Confer, Cameron Gifford, Bernard * This is Journal Paper No. 2248 from the Purdue University Agricultural Experiment Station.

Summer Records of Myotis sodalis in Indiana

Although the breeding range of Myotis sodalis remains a mystery, bat collecting in Indiana during the past decade has shed some light on its summer distribution. Lyon (1936) recorded the species from only Crawford (Wyandotte Cave, the type locality), Greene and Knox counties. Some of these were June and August specimens, but no mention was made of this fact. This may have been because sodalis was then so little known, having been described a short time previously by Miller and Allen (1928). Kirkpatrick and Conaway (1948) published a record of a female (Purdue Wildlife Laboratory Coll. 366) taken May 13, 1947, at Lafayette, Tippecanoe County. We have examined recent specimens from Clay, Kosciusko, Lawrence, Monroe, Montgomery, Parke, Steuben, Tippecanoe, Washington and Wayne counties. With the exception of the Lawrence and Monroe county records (which are for the wintering period) these additional localities from which sodalis has been taken are of considerable interest. Due to the paucity of published records for sodalis in summer, we have included all of …