HF 



bat morphological characteristics, and data from existing 

 dichotomous keys (Jenkins 1949; Golley 1962; Barbour 

 and Davis 1969; Hoffmeister 1989; Schmidley 1991). AJl 

 measurements taken exclusively for our key were from 

 specimens from the Georgia Museum of Natural History 

 at the University of Georgia. Because the lower jaw often 

 is damaged or missing from museum skeletal specimens 

 or skulls found in the field, we constructed our key so 

 that the lower jaw is not required for identification. 



Many existing keys to southeastern bats do not 

 discriminate between the skulls of eastern red bats 

 {Lasiurus borealis) and Seminole bats (Z,. seminolus). We 

 incorporated distinguishing data on the size of the 

 protuberance of the lacrimal ridge (shelf), that proved to 

 be nearly 75-percent accurate (Lowery 1974; Laerm et al. 

 1999). Not included in The Mammals of Georgia (Golley 

 1962), we also included discriminatory information on 

 the eastern small-footed myotis [Myotis leibii) in our key 

 to the skins. We did not provide information about the 

 differentiation of the myotids for the skull key. With the 

 dichotomous key to the skulls presented here, the user can 

 classify a skull only as belonging to the genus Myotis. 

 Although the skins of the six Myotis species that are found 

 in the Southeastern and Mid-Atlantic regions can be 



Figure 1 . — Standard bat measurements include total 

 length (TL), tail length (TV), forearm length (FA), 

 and foot length (HF). The inset illustrates the extent 

 of fusion in the epiphyseal gap of the finger joints of 

 adults and juveniles. Adult joints (AD) appear fused 

 and consist of a single protuberance; juvenile joints 

 (JV) are not fused (cartilaginous plates remain in the 

 joints) and consist of two protuberances or a single 

 protuberance that is larger and more tapered than in 

 adult joints. 



identified accurately using qualitative characteristics or 

 univariate metrics, myotid skulls cannot be distinguished 

 reliably using qualitative characteristics, univariate 

 metrics, or bivariate scattergrams.' Skulls of the six 

 southeastern myotid species can be identified accurately 

 (96+ percent correct classification) using complex 

 multivariate techniques such as discriminate function 

 analysis. 



Exclusive of myotids, many bat skulls can be identified by 

 counting the number of teeth in one upper quadrant 

 (one-half of the upper jaw) and measuring the greatest 

 length of the skull (from the posterior-most margin to the 

 anterior-most portion, not including the incisors) and 

 comparing these measures to dental formulae of each 

 species (Table 1 ) and the skull key. 



Locations of six standard body measurements used in 

 identification — total length (TL), tail length (TV), foot 

 length (HF), ear length (E), forearm length (FA), and 

 tragus length (TR) — are illustrated in Figures 1 and 2. 

 These measurements can be taken on dead specimens 

 prior to preparation or on live specimens prior to release. 

 Our key was designed using characteristics and 

 measurements recorded from adult individuals and may 



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