Information about the Mexican Long-nosed Bat (Leptonycteris nivalis), a species found in the State of Texas. Abstract. In this study we analyze the population dynamics of the migratory and nectarivorous Leptonycteris nivalis (Mexican long-nosed bat) in relation to foo. Learn more about the Mexican long-nosed bat – with amazing Mexican long- nosed bat videos, photos and facts on Arkive.
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Greater long-nosed bat
Most occurrences in Mexico are at elevations of 1, meters, but this bat been captured at an elevation of 3, meters see Aritaand the type specimen reportedly was caught near snow line at 17, feet 5, meters on Mt. The range has been described as extending into Guatemala and adjacent southern Mexico Hensley and Wilkins ; Simmons, in Wilson and Reederbut specimens collected from those areas were assigned to L.
Simmons in Wilson and Reeder described elptonycteris range of L. Area of Occupancy Comments: Suitable roosts may be a limiting factor; area of occupancy is quite small if based on the known area number of 2 km x 2 km grid cells occupied by roosting bats. Just a few roosting sites exist in the United States, but there could be additional sites that have not yet been detected.
Total adult population size is unknown but presumably exceeds 10, and may exceed , based on the bivalis range and the periodic presence of several thousand individuals in the single roost in Texas.
This species is widespread but “scarce” in most of its range AritaArita and Santos-del-Prado In Mexico, the species forms cave colonies of fewer than individuals orindividuals Arita Roost at Emory Peak Cave Texas: Large annual fluctuation may be in part due to some counts being made before or after the main period of bat occupation of the cave Cockrum and Petryszynor it may be an artifact of some bats being present but not detected Ammerman et al.
The number of roost-based occurrences or subpopulations with good viability is uncertain but likely there are not very many.
Several caves in central Mexico were known to contain considerable numbers in the past but now contain only small colonies leptobycteris none at all see USFWS High – medium Overall Threat Impact Comments: Primary threats include disturbance of roosts, loss of food sources through clearing of land for agriculture and human exploitation of agaves e.
Other threats may include negative effects of ingestion of pesticides applied to plants, competition for roosts and nectar, natural catastrophes, disease, and predation; however, these are not believed to be major limiting factors, though some of them could become significant for populations reduced to small size by other nivalks see USFWS These bats are sensitive to disturbance in their roosting sites they often quickly take flight upon human entry; WilsonWilson et al.
Human disturbance and destruction of roost sites is a common occurrence in Mexico. The availability of roost sites free from disturbance may be a significant limiting factor. A major problem for bats all over Mexico is that uninformed citizens frequently destroy all bats in a roost, nvialis them to be vampire bats USFWS The only known mating site for the species, Cueva del Diablo located in Tepoztlan, Morelos, Mexico, is threatened by residential development for tourism Emma P.
Gomez-Ruiz and Thomas E. Foraging habitat can be degraded or destroyed by harvesting of agave an important food resource. It has been estimated that bootleg mescal makers are eliminating betweenand 1, wild paniculate agave a year in Sonora alone. Agave plant parts are harvested just before they bloom; this prevents flowering and can prevent reproduction by the affected plant an agave plant grows for 10 to 20 years, flowers only once, then dies.
However, there are few places in Sonora or elsewhere in Mexico where wild Agave harvesting has eliminated a significant percentage of nectar-producing genets, and plants harvested by indigenous people generally produce vegetative offshoots that may eventually produce flowers Nabhan and Fleming Populations of unharvested plants persist in many areas that are not easily accessible to humans.
The negative impact of agave harvest probably is not as great as was previously believed. On the other hand, reduced pollination resulting from decreased bat populations may eventually lead to a reduction in agave distribution and abundance. Preliminary data suggest that Agave is the main food source for L. Human exploitation of wild agaves in the northern range needs to be evaluated to quantify this potential threat.
Some foraging habitat has been degraded or destroyed by expansion of agriculture and other land uses. Land clearing is a threat in northern Mexico, especially with recent plans for shale gas extraction and wind farm development Emma P. Evidence suggests that mainly pregnant females migrate to the North maternity caves have only been reported in the North ; wind turbine fatalities of pregnant females may pose a high risk to population stability leptonycteros better understanding of this risk is needed Emma P.
Changes in precipitation levels and timing have an effect on blooming events of Agave spp. This species may experience predation from owls, hawks, snakes, and mammals, but natural levels of predation likely are inconsequential to the overall status of the species. However, increased populations of domestic and feral cats and other predators near human habitations may affect the survival of colonies, particularly maternity colonies USFWS Unknown Short-term Trend Nuvalis Trend over the past 10 years or three generations is uncertain.
Long-term trend is unclear. Extent of occurrence and area of occupancy probably have not changed much, but the number of occurrences or subpopulations and population size may have dramatically decreased in some locations during the last three decades.
Wilson found that this species was either completely absent or present in reduced numbers in known roosts. nivaliw
The number of bats found represented only a fraction of the total reported in lleptonycteris studies. For example, in an nivvalis mine in Nuevo Leon, Mexico, where an estimated population of 10, was observed inno individuals of L. Another mine in Nuevo Leon had a ceiling covered with newborn bats inbut only one bat was found in A few other roosts had reduced numbers of bats compared to findings during previous surveys.
These changes could indicate a decline in the overall population, but they might reflect movement of bats among different roosting leptonycteirs in different years, or they could result from seasonal changes in bat distribution survey dates varied. A colony of L. Reasons for the fluctuations are not completely understood, but they apparently reflect annual variations in regional food resources number of flowering agave plants USFWSAmmerman and Tabor ; a similar pattern has been observed at a cave in Nuevo Leon, Mexico Moreno-Valdez et al.
Historical count data for Emory Peak Cave may leptonycheris be completely reliable; bats present in the cave may go undetected Ammerman et al. However, better population data based on improved monitoring methods are needed before a reliable trend determination can be made Ammerman et al. Further regular surveys are needed to leptonycterls important roost sites, abundance, and trends. Conservation of this bat will require maintenance of relatively large areas of wild agave Moreno-Valdez et al.
Identification and protection of currently and formerly occupied roost sites and protection of foraging habitat in at least several areas throughout the range are important conservation needs.
States and Canadian Provinces Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
Range depicted for New World only.
The scale of the maps may cause narrow coastal ranges or ranges on small islands not to appear. Not all vagrant or small disjunct occurrences are depicted. For migratory birds, some individuals occur outside of the passage migrant range depicted. For information on how to obtain shapefiles of species ranges see our Species Mapping pages at www.
This grayish brown bat has a leaflike nose projection and no tail; forearm mm Whitaker Leptonycteris curasoae is usually smaller, with a shorter forearm mm Whitaker Choeronycteris mexicana has a small tail. Litter size normally is 1. Young are born apparently in spring April-Juneprimarily in Mexico before females arrive in Texas, though pregnant females have been captured in Texas in late April BrownAmmerman et al.
In Texas, lactating females have been observed in June-July, flying juveniles in late June. Young are weaned in July or August. These bats are highly colonial.
Leptonycteris nivalis – Bats of Texas
These bats are effective pollinators of cacti and agave; the plants are dependent on bats for sexual reproduction. Y Long Distance Migrant: Y Mobility and Migration Comments: This species is migratory in the northern portion of its range Wilson et al. Seasonal movements likely correspond with food availability. Most northward migrants in Texas are females, but in New Mexico the sex ratio is more balanced Hoyt et al.
Riparian Terrestrial Habitat s: Desert, Woodland – Mixed Subterranean Habitat s: Habitats include desert scrub, nkvalis conifer-oak woodlands, and pine forests in the Upper Sonoran and Transition Life Zones; generally arid areas where agave plants are present USFWS Colonies roost in caves or similar mines and tunnelssometimes in culverts, hollow trees, or unused buildings. Roosting habitat requirements are not well known.
Frugivore, Nectarivore Immature Food Habits: Frugivore, Nectarivore Food Comments: In the northern part of the range, the bats often feed at the flowers of cacti and paniculate agaves. In Texas; nectar of mescal and Chisos agave flowers probably are the main food Schmidly The diet may include insects associated with flowers, and probably some fruits, especially in the southern part of the range.
Activity occurs throughout the year. Emergence to feed occurs relatively late in the evening. Conservation of this bat likely will require maintenance of relatively large areas of wild Agave Moreno-Valdez et al.
Planting of agave has been initiated in some areas of northern Mexico. Public education is needed to reduce the level of human disturbance and destruction of roost sites in Mexico. Populations need to be defined, then several of them throughout the range need to be adequately protected. Populations need to be defined, and movement patterns need to be better understood. Accurate censusing methods need to be developed and implemented.
Phyllostomid Bats Use Class: Bachelor colony Subtype s: An area occupied either historically or at present by a persisting or recurring bachelor male population.
Comprehensive Report Species – Leptonycteris nivalis
Identification evidence minimally includes collection or reliable observation and detailed documentation of one or more individuals. The EO includes both the colony site and the associated foraging areas. If separate, the colony site and foraging areas are bounded nivaalis separate polygons; that is, areas over which the bats simply commute to and from foraging areas and the colony are not included in the EO.