Natalus mexicanus (Chiroptera: Natalidae)

Abstract

Natalus mexicanus Miller, 1902 is the smallest species of Natalus and is commonly called the Mexican greater funnel-eared bat. This insectivorous bat is the most widely distributed species of Natalidae, occurring from northern Mexico to Panama, inhabiting mainly deciduous and semideciduous tropical forests, generally at elevations below 300 m. N. mexicanus, a cave-dwelling bat, is considered as a “Least Concern” species by the International Union for Conservation of Nature and Natural Resources, and some data indicate moderate population sizes in several caves, although the population status at other sites is currently unknown.

Genetic Consequences of Forest Fragmentation in a Widespread Forest Bat (Natalus mexicanus, Chiroptera: Natalidae)

“…This may be a consequence of habitat fragmentation, which should be interpreted as a warning signal, given that the loss of genetic variation and flow can reduce the ability of individuals to adapt to a changing environment, resulting in endogamic depression [121], lower reproduction [122,123], and a higher probability of extinction [124,125]. The information obtained for Natalus mexicanus in this study is also alarming because the current status of most of its populations is unknown [40], and during the development of our field work, we have been able to verify that some populations have either declined or completely disappeared due to human disturbances [126].…”

“…In these localities, geographic barriers (e.g., Sierra Madre Oriental, Sierra Madre Occidental, Isthmus of Tehuantepec) do not seem to hamper connections between the Gulf of Mexico and Pacific slopes, as well as with the Yucatan Peninsula; nonetheless, the gene flow is low (Table 5). Natalus mexicanus thrives in the interior of forests, although also being able to prosper in the remnants of tropical forests by using resources in the coastal corridors that stretch across landscapes [7,40]. Thus, we can assume that this species may be migrating locally through the Balsas depression or the Isthmus of Tehuantepec lowlands, both suggested as biological corridors for other bat species [50,[113][114][115].…”

“…In this context, a population genetic study on an insectivorous bat species such as Natalus mexicanus Miller 1902, which is being affected by habitat fragmentation [38,39], will be very helpful to determine the effects of landscape alterations on this type of organism. Natalus mexicanus is a small-sized species with a delicate body weighing from 3.0 to 8.0 g [40]. In Mexico, this species is distributed across two separate narrow strips stretching along the Pacific coast (Sonora to Chiapas) and the Gulf of Mexico (Tamaulipas to Tabasco), which converge in the area from the Balsas depression to the Yucatan peninsula [41], at elevations from sea level to 2540 m [42].…”

“…In Mexico, this species is distributed across two separate narrow strips stretching along the Pacific coast (Sonora to Chiapas) and the Gulf of Mexico (Tamaulipas to Tabasco), which converge in the area from the Balsas depression to the Yucatan peninsula [41], at elevations from sea level to 2540 m [42]. It usually inhabits the interior of forests, showing less mobility in landscapes outside forests [19], and is more abundant in well-conserved forests [43], where it forages insects from surfaces among vegetation, avoiding open spaces [40,44]. The distribution pattern of N. mexicanus is common among tropical Mexican bats [45] and is generally explained by ecological requirements [46].…”

“…Considering that Natalus mexicanus is a sedentary, common, and habitat-dependent species, that inhabits the interior region of forests [40], the present study aims to test the hypothesis that the growing fragmentation of Mexican tropical habitats is affecting gene flow among their populations; as a result, populations-even those previously considered abundant and not threatened-are becoming increasingly isolated and more vulnerable to extinction. Our aim was to infer levels of population connectedness in N. mexicanus throughout its distribution range in Mexico, where the natural landscapes have been fragmented as a result of human activities, and to test whether population genetic isolation is occurring due to the lack of dispersion.…”