Lasiurus ega (Gervais 1856)

D, K D., L, A M., M, B, B, R J. & A, L K., 2012, N C R 14 B S B S S T D S H S, Occasional Papers of the Museum 315, pp. 1-16 : 4-5

Lasiurus ega (Gervais 1856)

Southern Yellow Bat

The southern yellow bat is a neotropical species that has expanded its range northward into the United States in recent years ( Ammerman et al. 2012). It has been suggested by Spencer et al. (1988) that these bats are using the increasing number of ornamental palm trees planted by residents in the Southern Texas Plains and Gulf Coastal Plains ecoregions of Texas. This medium sized yellow bat is sometimes confused with Lasiurus intermedius , the northern yellow bat, which also occurs in southern Texas. Several morphological features vary between the two species. Overall size can be used for determining if an adult specimen is L. ega (average total length of 118 mm) or L. intermedius (average total length of 133 mm) ( Ammerman et al. 2012). Skull features are difficult to use in specimens from DSHS because of damage that occurs to the skull when brain tissue is removed for rabies testing. In that case, and when specimens are juveniles, additional confirmation (such as from molecular data) might be required in order to determine the species (Tipps et al., in press). L. xanthinus , the western yellow bat, is also similar to L. ega ( Baker et al. 1988) . However, confusion between these two species is rare because they occur in different ecological regions of Texas ( Schmidly 2004). We present a total of six county records including records in Fayette and Comal counties that extend the known range of the southern yellow bat northward by more than 200 km.

Aransas County.—Aransas County is just outside the northeastern limit of the southern yellow bat’s previously known range. A female specimen (TTU 113429, TK 171041) was received on 7 July 2010; this Gulf Coast county expands the known distribution of the species. The specimen had a recorded total length of 78 mm, a hind foot length of 8 mm, and a forearm length of 48 mm.

Comal County.— An adult male specimen ( ASNHC 15072 , ASK 9381 ) was received on 1 December 2011. This specimen had a total length of 111 mm, a hind foot length of 10 mm, and a forearm length of 47 mm. This record extends the known range of the southern yellow bat into the Edwards Plateau and the Texas Blackland Prairies ecoregions .

Fayette County.— An adult female ( TTU 113509 , TK 171121) was received on 17 November 2009 with a recorded total length of 115 mm, a hind foot length of 9 mm, and a forearm length of 46 mm. The total length of the specimen complies with the expected length of L. ega . Therefore , Fayette County extends the known range of the southern yellow bat. Fayette County is included in the Texas Blackland Prairies and East Central Texas Plains ecoregions .

Hidalgo County.— Hidalgo County previously was listed by Ammerman et al. (2012) as a literature record based on Chapman and Chapman (1990). Chapman and Chapman (1990) examined a single specimen housed at Pan American University. An additional six specimens of L. ega were received from this county and are important for validating established populations there. The first was a female specimen (TTU 113592, TK 171204) on 23 April 2008. Another adult female (TTU 113594, TK 171206) was received on 4 May 2008. A female (TTU 113432, TK 171044) was received on 9 June 2009. In 2010, an adult female (TTU 113436, TK 171048) was received on 18 February. A male (TTU 113434, TK 171046) was received on 30 June 2010. On 8 July 2010, a juvenile female (TTU 113433, TK 171045) was received. Thus, populations of L. ega appear to be established in Hidalgo County.

Webb County.— A female specimen ( TTU 113425 , TK 171037) was received on 18 March 2010. This county is located within the Southern Texas Plains and previously was documented as a DSHS record. However , because the specimen supporting this record was discarded, we consider the new voucher as a county record .

Willacy County.—A female specimen (TTU 113438, TK 171050) was received on 11 December 2008. The specimen had a hind foot length of 9 mm and a forearm length of 47 mm. Total body length was not recorded for this specimen. This record is within the previously known distribution for the species.