Department, BCI partner to improve bat habitat at Double E

The New Mexico Department of Game and Fish (Department) Share with Wildlife program has partnered with Bat Conservation International (BCI) to monitor and improve habitat for nectar-feeding bats on the Double E Wildlife Management Area (WMA).

Double E WMA is on the southwest edge of the Gila National Forest outside of Gila, New Mexico. The Double E WMA consists of large cottonwood and sycamore trees lining Bear Creek, but also has many acres of higher-elevation pinyon juniper hills.  In 2020, Department habitat biologist Jennifer D’Annibale officially documented a large, dense patch of Palmer’s agave (Agave palmeri) on the Double E WMA by sending photos to a nectar-feeding bat expert.  This photo sparked interest from multiple nectar-feeding bat experts, as this was one of the most northern locations where this species of agave has been documented and is known to be an important foraging source for these bats.

In New Mexico, the range of Palmer’s agave is primarily in the Bootheel and throughout the Sky islands, and, to a lesser extent, in the Gila region, mostly in the Burro Mountains, so it was exciting to see the presence of agave farther north on the WMA.

This particular a group of nectar-feeding bats forage on the flowers of columnar cacti and agave species, such as the Palmer’s agave. These bats include the Mexican long-tongued bat (Choeronycteris mexicana), Mexican long-nosed bat (Leptonycteris nivalis) and lesser long-nosed bat (Leptonycteris yerbabuenae), and they migrate from south-central Mexico to the southwestern United States foraging along the way. The Mexican long-nosed bat is considered endangered by the United States, and all three of these bats are on the Species of Greatest Conservation Need (SCGN) list that was compiled in the Department’s State Wildlife Action Plan.

Once the patch of Palmer’s agave was confirmed on the Double E WMA, acoustic detectors were deployed in 2021, and the WMA was documented to have high activity of long-nosed bats. However, the two species of long-nosed bats cannot be differentiated using acoustics, so additional survey methods were needed to confirm which species are foraging here. To learn more about what species exactly are using this patch and recognizing that this might be an important area for these bats, the Department partnered with BCI through the Share with Wildlife program in 2024.

BCI completed a non-invasive survey method for identifying the species foraging on the agave patch with environmental DNA collection (eDNA) that fall. Once the eDNA was analyzed, BCI was able to confirm that the endangered Mexican long-nosed bat and the lesser long-nosed bat species were utilizing the Palmer’s agave on the Double E WMA. This detection, along with a handful of eDNA samples collected in 2024 by BCI, detected the Mexican long-nosed bat outside of its known range. Currently, this area is about 100 miles north of the closest known roost for the endangered Mexican long-nosed bat.

Not only was the Mexican long-nosed bat detected outside of its known range, but there were also high detection rates with the eDNA. This suggested that these northern patches of Palmer’s agave are important foraging areas for these bats in the late summer before migrating back to Mexico.

Additionally, this patch of agave will only become more important as the state experiences more extreme droughts in the lower elevations, where Palmer’s agave is primarily found. This agave patch will provide a food source for these bats as the surrounding area becomes hotter and drier, and other food sources die off as a result. However, the Department and BCI recognized that the agave patch on the Double E WMA wasn’t nearly robust enough to support a large population of bats, and that it is important to complete agave habitat enhancement work in the area.  BCI has collected more eDNA samples during the summer. They also collected seeds and are actively growing out agave from the Double E WMA patch to preserve any unique genetics. They arecurrently mapping all the agave on the property (more patches have been found!), and planning on planting Palmer’s agave in three separate locations on the WMA.

BCI is currently identifying suitable locations for future agave plantings, with crews coming in to plant agave in the selected areas afterward.

By planting agave in various locations, it will allow us to create a robust population of agaves on the WMA.  In addition to improving the agave population and habitat, the Department also hopes to rehabilitate two or three water sources near the existing agave patch, allowing bats and all wildlife in the area to have access to water year-round.  The Department’s Share with Wildlife program was initiated in 1981 to help species that do not receive funding from any other source. The program funds research, education, habitat enhancement and rehabilitation projects. It is largely funded through the state income tax check-off program, as well as direct donations and the sale of Share with Wildlife license plates, along with matching federal funds. More information on the Share with Wildlife program is available on the Department’s website.