Lesser Log-Nosed Bat

Leptonycteris curasoae yerbabuenae

Written by Sadie Carlson

Photo by Merlin D. Tuttle, Bat Conservation International

Bat Overview
2.5 inches from head to tail and 10 inches from wing tip to wing tip. The species has a yellow/grey hued coloring. This desert bat is nocturnal and feasts primarily on pollen, nectar, paniculate agave fruit, and columnar cacti. Before being exposed to human engineering, the bat presided solely in caves and trees, but now lives in abandoned buildings as well.

Geographic range

    Currently inhabiting only 40 roosts, within the U.S., the Lesser Long-Nosed bat Is known to preside in the Arizona counties of Cochise, Graham, Greenlee, Maricopa, Pima, Pinal, Santa Cruz, and Yuma, and in the New Mexico County of Hidalgo. Outside of the U.S. the bat is known to inhabit parts of Mexico.¹ Historically, the bat is recorded to have had a territory spanning from the Peloncillo mountains in New Mexico, through a large portion of Mexico, and into El Salvador.² This particular species of bat is known to migrate between its northern nesting areas in the U.S., and its winter lodging in Mexico.³

Listing History

In 1987 it was first proposed that the Lesser Long-Nosed Bat be added to the endangered species list. The Species was first listed on the endangered (vs. critically endangered)species list as “Endangered” on 09/30/1988. The report containing the final ruling on the listing can be found at http:/ecos.fws.gov/docs/federal_register/fr1487.pdf . It wasn’t until 1998 that a formal recovery plan was drafted.

                             Word Search         

           AGAVE                                ARIZONA

               BAT                                     CAVE

           COLUMNAR CACTI            ENDANGERED

           LESSER                              LONG NOSED

           MEXICO                              MIGRATION

           MINE                                   NEW MEXICO

           QUESTIONABLE

Why were they listed?

The main causes for listing include diminishing population sizes. Estimations for current population size is estimated to be 60,000, much lower than it was in previous years. This assertion is widely regarded as truthful, even though no reports have been validated as conclusive. All the same, the species was has not recently been spotted in many of the caves and mines that it was known to inhabit during the 1970s. Although this report was also lacking in certainty, the long nosed bat has been listed is due to the detriments that would result in its extinction. The Bat is a known pollinator of the agave plant. If the Lesser long nose bat were to become extinct, and subsequently cease pollination of the agave, many scientists claim that we would see a large reduction in agave plants. This claim is weakened by the fact that many other species, such as bats and birds aid in the reproduction of the agave plant, thus creating the claim that the bats presence does not have a substantial impact on the agave plant.

But are they really at risk?

Since the severity of the endangerment of the bats is under question, the gravity of the causes are also uncertain. The most likely causes include the closing of abandoned mines. Abandoned mines play a crucial role in the nesting of the lesser long nosed bats. As safety precautions have encouraged the closure of abandoned mines, many bats have lost their breeding grounds. Beyond caves, these bats roost in abandoned homes, hollow trees, and any undisturbed dark space. These bats are so sensitive that even a visit from a curious individual can cause a mass abandonment from the roosting space. This disturbance greatly affects breeding, and can lead to an overall decline in species numbers.4

What happens when you close the door on an abandoned house/bat roost? …RECOVERY!

The U.S. Fish and Wildlife service has published a very comprehensive recovery plan. The entire process is expected to be relatively quick and inexpensive; costing an estimated $1,061,000. The first step towards recovery is to protect roosting sites and food supplies. The next order will be to monitor and survey the roost sites throughout the bats native territory. This will also include surveys of other bat species. Lastly, the recovery plan calls for more research into the bats so that we can better know what is affecting them.5 More detailed information can be found in the recovery plan which is located at: http://ecos.fws.gov/docs/recovery_plan/970304.pdf

What can you do?

Since very little is known about the lesser long nosed bat, the best thing that we can do is avoid disturbing them. So if you are ever in their native region, stay out of old trees and caves. Also, avoid abandoned houses and mines. In general, it is a wise choice to avoid all of those locations. The next thing that we can do is stay connected. As the recovery plan progresses, and we learn more about what is affecting the Lesser Long Nosed Bat, we will better know how to protect them. Lastly, all protective services are being paid for by the federal government. To extend the aid to more species, write your local representative asking for more of the federal government’s budget to be allocated to environmental protection services.

References

1. Species Profile for Lesser Long-Nosed bat, ECOS, U.S. Fish and Wildlife Service
2. General Species information, July 2001, Arizona Ecological Service Field Office
3. 5 Year Review: Summary and Evaluation, U.S. Fish and Wildlife Service, LLNB
4. Cockrum 1991, Hoyt et al. 1994, Lesser Long Nosed Bat Recovery Plan, May 1998, U.S. Fish and Wildlife Service.
5. Lesser Long Nosed Bat Recovery Plan, May 1998, U.S. Fish and Wildlife Service.