Abstract: The Arizona myotis or occult myotis <i>(Myotis occultus)</i> is a southwestern U.S. endemic bat that possesses unique morphological variation throughout its distribution. Recent morphological analyses of crania, jaw, and dental features of M. occultus from Colorado and New Mexico have shown that there are three sizes related to geography. In general, individuals located in southern Colorado were overall the smallest in size compared to individuals from New Mexico. However, within New Mexico, individuals located in the lowlands of the Rio Grande Valley were smaller than the largest individuals occurring at higher elevations (e.g., mixed coniferous forests) throughout the state. Analyses of guano revealed that <i>M. occultus</i> from Colorado consumed mostly soft-bodied prey items (e.g., midges and wasps), whereas individuals from New Mexico consumed hard-bodied prey items (e.g., beetles) and differences in diet are likely one reason for geographic variation in morphology. Temperatures and time between first and last frosts also appear to be indirect contributing factors for morphological variation across the range of M. occultus. Additional key findings for diet of <i>M. occultus</i> include the presence of economic pests (i.e., bark beetle and click beetle). In addition to the analyses of morphological differences and diet of <i>M. occultus</i>, ectoparasites were also collected and identified. Prior to this study, only two ectoparasites were known to occur on M. occultus. After close examination of 202 specimens of <i>M. occultus</i>, over 2000 ectoparasites belonging to 9 families and 13 genera were documented. This represents the first extensive study of ectoparasites occurring on <i>M. occultus</i>. Additional highlights include the discovery of three new species of mites belonging to the genera <i>Alabidocarpus</i>, <i>Pteracarus</i>, and <i>Chiroptonyssus</i>.
Purpose: Little is known about the feeding ecology of southwestern bat species, even more so for the insectivorous bat Myotis occultus. Understanding diet of insectivorous bats will provide better understanding on impacts to agricultural pests as well as pest species on southwestern forests. Also, by understanding the diversity of ectoparasites occurring on bat species, information obtained can give insight on possible zoonotic diseases and possible impacts on rates of transmission to humans. Moreover, understanding systematic relationships between host and parasite can give insight on past, as well as, future ecological changes over time. From Piaggio et al. (2002), the clade and subclade groupings of M. occultus in New Mexico will be used as a guideline to determine if there are associated patterns in morphology and distribution.
Supplemental Information: Information used to prepare this metadata was extracted from entries in the USGS BASIS+ database for 83279SW.13.0 on 20071002

Progress: In work
Update Frequency: As needed

Theme Keywords: None, inventory, monitoring, migration, declining avian species, small mammals, reptiles, conservation ecology, stable isotopes, arid ecosystems, desert grasslands, taxonomy, disease, ecology, population status, rabies, technical assistance, wildlife, Amphibians, Bats
Place Keywords: United States, New Mexico, Colorado, NM, CO

Access Constraints: Contact principal investigator after completion of project.
Usage Constraints: Contact principal investigator after completion of project.