06.21.17

Spring and summer are memorialized for good reason: along with warmer weather and longer days come spectacular blooms in every habitat. In April and May, agave and columnar cacti like organ pipe and saguaro unfurl their musky night blooms, and migrating bats from Mexico follow this nectar trail north to fuel their bodies during breeding season.

As key pollinators of such desert plants, the Mexican long-nosed (Leptonycteris nivalis), lesser long-nosed (Leptonycteris yerbabuenae), and Mexican long-tongued (Choeronycteris mexicana) bats play an important role in desert ecology. These three species are found only in the southwest of the United States: in southeastern Arizona, the boot heel of southwestern New Mexico, and in Big Bend National Park in extreme southern Texas. Although these species are primarily nectar-feeding pollinators, they also disperse seeds when they switch to eating cactus fruits later in the summer.

These species are under pressure from increased development, human disturbance at their cave roosts, and loss of habitat. Shifts in the bloom seasons of their primary food plants and extreme weather events linked to climate change could also threaten these migratory species that depend on predictable timing of flowering.

The Mexican long-nosed bat is considered endangered in both the U.S. and in Mexico, and researchers from both countries are working together on the protection and conservation of this species. The lesser long-nosed bat, once also considered endangered, was recently lifted from imperiled status in Mexico. Earlier this year, the species was proposed to be de-listed from the Endangered Species Act by the U.S. Fish and Wildlife Servicean indication that conservation efforts to protect and improve the population outlook of these species can be successful.

Here are a few ways to help if you, or someone you know, lives in the southwestern U.S.

1. Keep your hummingbird feeder clean. Both species will readily visit a feeder filled with the same 4:1 water-sugar solution hummingbirds enjoy. Change out the nectar regularly, being sure to rinse the bottle thoroughly after sanitizing with white vinegar or a mild bleach solutionnever soap.

2. Nectar Recipe

Mix 1 cup of sugar into 4 cups of water in a small saucepan on the stove.

Bring the mix to a boil, then remove from the heat.

Cover and allow to cool before using or pouring into a feeder or storage bottle.

3. Get involved in habitat restoration, or plant native food sources. Gardening for nectar bats can be challenging, as they tend to prefer areas where they can visit a great many flowers in a night, and plants like columnar cacti can take decades to mature. Dont hesitate to plant your own, but also check out volunteer and educational opportunities with groups involved in habitat restoration:

Arizona Native Plant Society

Sky Island Alliance

New Mexico Native Plant Society.

4. Document bat visits. Though most smartphone cameras cant keep up with the rapid dip-n-sip maneuvers bats employ in dim light at a feeder, a decent camera and multi-flash setup will do the trick for capturing visual evidence of your visitors.

Mount the camera on a tripod and use a remote shutter release to avoid shaky images.

A dim porch light shouldnt bother your visitors, either, and will improve the quality of your pictures.

Setting up flashes in several places to provide light from various angles helps avoid deep, one-directional shadows.

Have patience! It can take bats a while to find the feeder and become acclimated to the surroundings.

And dont forget to report your observations through citizen science projects like Marana, Arizonas bat and hummingbird study or iNaturalist.