To some extent, lack of information regarding basic life history for this species may be attributed to the combination of Leptonycteris nivalis with Leptonycteris curasoae in classification of these species from 1940-1962 (U.S. Fish and Wildlife Service, 2000).
Perception Channels: tactile ; chemical
Leptonycteris nivalis was listed in 1988 as an endangered species by the US Fish and Wildlife service and by the state of Texas. In 1990, New Mexico listed L. nivalis as endangered, and in 1991 L. nivalis was listed as endangered under the Mexican Endangered Species Act. The Mexican long-nosed bat population has been steadily declining over the years due to declining number of roost sites and the increased harvesting of Agave sp. to make liquor; these harvests decreased the primary food source of the bats (U.S. Fish and Wildlife Service, 2000). In southern Mexico many L. nivalis have been mistaken for vampire bats and killed in attempts to reduce the number of that species (Texas Parks and Wildlife, 2001). Efforts of conservation focus on increasing the abundance of roost sites, protecting existing roost sites, protecting critical Agave sp., and expanding biological information including the obtainment of an accurate population estimate (U.S. Fish and Wildlife Service, 2000).
Temperate North American bats are now threatened by a fungal disease called “white-nose syndrome.” This disease has devastated eastern North American bat populations at hibernation sites since 2007. The fungus, Geomyces destructans, grows best in cold, humid conditions that are typical of many bat hibernacula. The fungus grows on, and in some cases invades, the bodies of hibernating bats and seems to result in disturbance from hibernation, causing a debilitating loss of important metabolic resources and mass deaths. Mortality rates at some hibernation sites have been as high as 90%. While there are currently no reports of Leptonycteris nivalis mortalities as a result of white-nose syndrome, the disease continues to expand its range in North America.
US Federal List: endangered
CITES: no special status
IUCN Red List of Threatened Species: endangered
Leptonycteris nivalis has been known to roost on attic and parking garage ceilings. Beyond the inconvenience of having a bat living in your home, long-nosed bats produce large amounts of bat excrement or guano that can sustain bacteria and insects. The breakdown process of guano also releases large amounts of ammonia, which if humans are exposed to for periods of time can cause lung deterioration (Garza, 2001).
Agave sp. are of great economic importance in Mexico. Fibers called henequin are produced from the leaves of certain species of Agave. These fibers are exported, and they generate a substantial amount of revenue for some regional and local economies in Mexico. Tequila, another highly exported good produced in Mexico is primarily produced from Agave tequilana. The sale of tequila in international markets also produces a large amount of revenue for the country. The reproductive success of Agave spp. relies on the Mexican long-nosed bat to pollinate and cross pollinate plants. Without the bats, Agave seed count would drop to 1/3000th of normal (Arita & Wilson, 1987). L.nivalis also produce mass quantities of guano, which can be collected and used as fertilizer (Garza, 2001).
Positive Impacts: produces fertilizer; pollinates crops
L. nivalis has a very important role in the ecosystem; its presence directly and indirectly affects many biological interactions within its community. Many plants, like Agave, depend on the bat for the cross-pollination that maintains crucial genetic diversity within each plant species. Other species are dependent on plants pollinated by L. nivalis for their food and shelter. These include bees, moths, lizards, hummingbirds, woodpeckers, orioles, finches, sparrows, and field mice (Arita & Wilson, 1987). A decline in L. nivalis population could mean a reduction in the Agave population and many other species that rely on these plants, thereby changing the dynamics and interactions within the community. Leptonycteris nivalis has a mutualistic or symbiotic relationship with Agave, its primary food source (U.S. Fish and Wildlife Service, 2000).
Ecosystem Impact: pollinates; keystone species
Mutualist Species:
In general Mexican long-nosed bats are nectarivores. They feed primarily on the nectar of Agave spp. Researchers have suggested that Mexican long-nosed bats physical adaptations of short ears and the presence of a triangular noseleaf are evidence that they use their sense of smell to locate Agave sp. plants rather than echolocation (Arita and Wilson, 1987). Mexican long-nosed bats feed secondarily on pollen from cactus flowers, and some berries and fruits. Leptonycteris nivalis feeds at night in flocks when Agave sp. are blooming. Its migratory patterns also match the blooming patterns of certain plants of Agave such as A. angustifolia (mezcal plant), A. salmiana (pulque plant), and A. tequilana (tequila plant) (Arita, 1991). Mexican long-nosed bats forage by hovering over the blooming Agave and by clinging to herbacious vegetation. Since L. nivalis eat a lot of nectar, their demand for water is very low to absent (New Mexico Game & Fish, 2000).
Plant Foods: fruit; nectar; pollen
Primary Diet: herbivore (Nectarivore )
Leptonycteris nivalis is a migratory species, with a range that includes W Texas, New Mexico, and SE Arizona (U.S. Fish and Wildlife Service, 2000), and extends south spanning Mexico, Honduras, and Guatemala (BCI, 2001).
Biogeographic Regions: nearctic (Native ); neotropical (Native )
The Mexican long-nosed bat primarily lives at elevations ranging from 1,550 - 9,330 feet in habitats described as “desert scrub, open conifer-oak woodlands, and pine forest habitats in the Upper Sonoran and Transitional Life Zones” (U.S. Fish and Wildlife Service 2001). During the day, L. nivalis roosts in sheltered places like caves, hollow trees, and mines. However, information on roosting habitats is limited (U.S. Fish and Wildlife Service, 2000).
Range elevation: 516.67 to 3110 m.
Terrestrial Biomes: desert or dune ; forest ; scrub forest
The average life span of the Mexican long-nosed bat is approximatly 10 years (Texas Parks and Wildlife, 2001).
Average lifespan
Status: wild: 10 years.
Leptonycteris nivalis is 70-90 mm long, weighing 18-30 g. Their hair coat on their back is pale brown to gray. They have three vertebrae in their tail; however, it is not visible externally. L. nivalis has a third finger that measures 105mm. Long hairs protrude from and extend past a narrow piece of skin along the inside edge of each leg called the interfemoral membrane or uropatagium. They have an elongated snout with a triangular nose leaf on the end. In order to feed on nectar, Mexican long-nosed bat have a long tongue with inward-pointing, elongated papillae at its tip (U.S. Fish and Wildlife Service, 2000). The dental formula is 2/2, 1/1, 2/3, 2/2x2 = 30 (Davis & Schmidly, 1997).
Average mass: 18-30 g.
Range length: 70 to 90 mm.
Other Physical Features: endothermic ; bilateral symmetry
Some studies have shown that L. nivalis may have two breeding peaks a year, one in spring and one in September. Other studies have shown that the breeding season is limited to the month of May (U.S. Fish and Wildlife Service, 2000). L. nivalis give birth to one offspring annually in Mexico in caves. Female Leptonycteris nivalis carry the offspring inflight until it can fly on its own when it is weaned, usually a couple of months after birth (Davis and Schmidly, 1997).
Breeding season: May possibly September
Average number of offspring: 1.
Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal ); viviparous
Parental Investment: altricial ; female parental care
The greater long-nosed bat or Mexican long-nosed bat (Leptonycteris nivalis) is a species of bat in the family Phyllostomidae. It is found in Mexico and the United States.[1] It chiefly consumes pollen and nectar, particularly from agave plants and cacti.[1] Its habitat includes desert scrub and open woodlands.[1] It is threatened by habitat loss.[1]
They are sooty brown in color, with a darker dorsally and lighter ventrally. Individual hairs are white at the base, and silver at the tips.[2] Their forearms are 54–59 mm (2.1–2.3 in) long.[3] They have moderately-furred interfemoral membranes, and their short tails only have three vertebrae.[2] Their muzzles are elongated, and their tongues are long and tipped with filiform papillae.[2] The tongue attaches at the posterior side of the sternum. Their nose-leafs are triangular and erect.[2] The average mass is 24 g (0.85 oz)[2] Their ears are 15 mm (0.59 in) long.[2] Like other nectarivores, this species has reduced teeth, missing the third molar while the other two molars are weakly cusped.[2] Loss of teeth and dental ridges indicate accurately that their diet does not necessitate biting and chewing.[4]
The species is found in southern Texas, Arizona, and New Mexico from June through August.[5][6] It is found in central Mexico throughout the rest of the year.[5] They roost primarily in caves and mines, but can also be found in unoccupied buildings, hollow trees, and even sewers.[5] While it has been alleged that the bats are found as far south as Guatemala,[7] the IUCN disputes this notion, and lists its southernmost occurrence as central Guerrero.[1]
Little research has focused on reproduction in this species, but there are speculations based on this limited body of work. Mating occurs in November and December in Cueva del Diablo, which coincides with the greatest availability of food around the cave.[5] They likely have a polygynandrous mating system, where males and females mate multiple times with different individuals.[8] Because male testes are significantly larger during the mating season and females mate with multiple males, there is likely sperm competition between males.[5] Females are hypothesized to exhibit sperm storage or embryonic diapause.[5] It is thought that they are monoestrous; therefore they only breed once per year.[5] Birth likely occurs during May, during female migration to northern Mexico or the southwestern United States.[5] Litters likely consist of a single pup.[9] Males are likely non-migratory, and adult males are rarely encountered in the United States.[10] Females form maternity colonies in the northern parts of their range, with lactating females and their young arriving at a cave in Texas in June.[11] There are records, however, of pregnant females arriving as early as mid-April, which shows that some females do not give birth until completing migration.[10] Based on censuses, it is thought that the pups do not become volant until July.[12] The adult females and their young leave Texas in August.[11]
While the greater long-nosed bat consumes nectar from the same plants as the southern long-nosed bat, the two species utilize different habitats. The greater long-nosed bat prefers higher altitudes and lower temperatures than the southern long-nosed bat, though they're both found in dry habitats.[13] The greater long-nosed bat selects habitats with more pine and oak trees than the southern long-nosed bat.[13] The species mates in only one known cave–Cueva del Diablo near Tepoztlán, Mexico, which it shares with the common vampire bat and Parnell's mustached bat.[5]
The greater long-nosed bat consumes nectar from multiple plants, including tree-like cacti, Ceiba trees, shaving brush trees, morning glory trees, powder puff plants, flowering shrubs, and four species of Agave (Agave dasylirioides, Agave horida, Agave inaequidens, and Agave of Salm).[14] This species is highly opportunistic, rotating its dietary selection as different plants come into bloom.[14]
Population numbers of this species have likely been in decline for several decades.[5] In 1988, the United States Fish and Wildlife Service listed it as endangered.[15] The species is listed as threatened in Mexico.[16] In 1995, The Program for the Conservation of Migratory Bats between Mexico and the United States was started by a concerned group of international bat specialists in response to a decline of multiple bat species in Mexico.[5] PCCM has been valuable in conducting censuses of the greater long-nosed bats in Cueva del Diablo.[5] To reduce vandalism in Cueva del Diablo and promote appreciation of bats, PCCM created a series of children's books, educational activities, and TV reports.[5] In 2013, Bat Conservation International listed this species as one of the 35 species of its worldwide priority list of conservation.[17] There is evidence that the population in the United States has increased since 1984, with the population in Arizona one hundred times greater in 2000 than it was in 1984.[6] Because it is a highly colonial species, disturbance at a single cave can have a significant negative impact on the entire species.[6]
The greater long-nosed bat or Mexican long-nosed bat (Leptonycteris nivalis) is a species of bat in the family Phyllostomidae. It is found in Mexico and the United States. It chiefly consumes pollen and nectar, particularly from agave plants and cacti. Its habitat includes desert scrub and open woodlands. It is threatened by habitat loss.
