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86 result(s) for "nectar‐feeding bats"
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Foraging Movement Patterns of Lactating Mexican Long‐Nosed Bats in Central Mexico
The Mexican long‐nosed bat (Leptonycteris nivalis) is a nectar‐feeding bat distributed seasonally between Mexico and the United States, and it has been declared an endangered species in both countries. Here, we describe for the first time the movement patterns and locations of foraging areas used by lactating females from the only known maternity roost in central Mexico. GPS loggers were placed on 29 lactating females, adhered to the interscapular area with short‐term surgical glue. We obtained movement tracks of at least one night for 21 different individuals. Movement patterns were identified using the first passage time segmentation method and classified into commutative and foraging flights. Bats made up to three trips on the same night, visiting between one and three foraging areas. On average, the total distance traveled was 61.72 km per night (minimum 23.11 km, maximum 160.55 km), and 37 foraging areas were identified, located between 13 and 40 km north of the roost, mainly in desert shrublands, followed by agricultural areas and temperate forests. In these places, they spent most of their time outside the roost (2.16 h mean ± 1.14 h SD), feeding on the resources available in an average area of 0.38 km2. Bats traveled long distances each night, using areas with abundant wild and human‐cultivated floral resources, reflecting the importance of integrating movement ecology for the design of conservation and habitat management strategies that ensure the availability of necessary resources for this species. RESUMEN El Murciélago Magueyero Mayor (Leptonycteris nivalis), es un murciélago nectarívoro que se distribuye estacionalmente entre México y Estados Unidos, la especie está declarada en peligro en ambos países. En este trabajo, describimos por primera vez los patrones de movimiento y las ubicaciones de las áreas de forrajeo de hembras lactantes en el único refugio de maternidad conocido en el centro de México. Se colocaron dispositivos GPS en 29 hembras lactantes, adheridos al área interescapular con pegamento quirúrgico de corta de duración. Se obtuvieron rutas de movimiento de al menos una noche para 21 individuos diferentes. Los patrones de movimiento se idenfiticaron utilizando el método de segmentación pasaje de primer tiempo y se clasificaron como vuelos conmutativos y de forrajeo. Los murciélagos realizaron hasta tres viajes en la misma noche y visitaron entre una a tres áreas de forrajeo. En promedio, la distancia total recorrida fue de 61.72 km por noche (mínimo 23.11 km, máximo 160.55 km). Se identificaron 37 áreas de forrajeo localizadas entre 13 y 40 km hacia el norte del refugio, principalmente en matorrales xerófilos, seguido de áreas agrícolas y bosques templados. En estos lugares, los murciélagos pasaron la mayor parte de su tiempo fuera del refugio (2.16 h mean ± 1.14 h SD), aliméntadose de los recursos disponibles en un área promedio de 0.38 km2. Los murciélagos recorren grandes distancias cada noche, utilizando áreas con abundantes recursos florales silvestres y cultivados, reflejando la importancia de integrar la ecología del movimiento en el diseño de estrategias de conservación y manejo de hábitat que aseguren la disponibilidad de los rercusos necesarios para la especie. We tracked 21 lactating females of a migratory and endangered nectar‐feeding bat using GPS devices, and analyzed their foraging movements in one of the most important maternity roosts for the conservation of the species. Bats foraged within 50 km from the roost, made up to three foraging trips on the same night, and visited multiple foraging grounds with an average area of 0.38 km2.
evolution of bat pollination: a phylogenetic perspective
BACKGROUND: Most tropical and subtropical plants are biotically pollinated, and insects are the major pollinators. A small but ecologically and economically important group of plants classified in 28 orders, 67 families and about 528 species of angiosperms are pollinated by nectar-feeding bats. From a phylogenetic perspective this is a derived pollination mode involving a relatively large and energetically expensive pollinator. Here its ecological and evolutionary consequences are explored. SCOPE AND CONCLUSIONS: This review summarizes adaptations in bats and plants that facilitate this interaction and discusses the evolution of bat pollination from a plant phylogenetic perspective. Two families of bats contain specialized flower visitors, one in the Old World and one in the New World. Adaptation to pollination by bats has evolved independently many times from a variety of ancestral conditions, including insect-, bird- and non-volant mammal-pollination. Bat pollination predominates in very few families but is relatively common in certain angiosperm subfamilies and tribes. We propose that flower-visiting bats provide two important benefits to plants: they deposit large amounts of pollen and a variety of pollen genotypes on plant stigmas and, compared with many other pollinators, they are long-distance pollen dispersers. Bat pollination tends to occur in plants that occur in low densities and in lineages producing large flowers. In highly fragmented tropical habitats, nectar bats play an important role in maintaining the genetic continuity of plant populations and thus have considerable conservation value.
The pollination biology of two paniculate agaves (Agavaceae) from northwestern Mexico: contrasting roles of bats as pollinators
Paniculate agaves from tropical deserts depend on nectar-feeding bats for their reproduction, while species from extratropical areas near the northern limit of Leptonycteris curasoae are pollinated by diurnal and nocturnal insects and birds. Agave angustifolia is a paniculate agave with a broad distribution in Mexico whose range coincides with the distribution of L. curasoae, while A. subsimplex has a narrow distribution in Sonora within the range of nectar-feeding bats. We studied the pollination biology of A. angustifolia and A. subsimplex in northwestern Mexico to evaluate the relative importance of bat pollination in a region where L. curasoae is seasonal. Flower visitors included a wide variety of animals, with bats having greater visitation rates in A. angustifolia. A pollinator-exclusion experiment revealed that bats were responsible for most of the control fruit set in A. angustifolia, whereas for A. subsimplex, diurnal and nocturnal visitors were equally effective. Overall, our data indicate that in central Sonora, A. angustifolia depends on nectar-feeding bats for its sexual reproductive success, while A. subsimplex relies on both diurnal and nocturnal pollinators. Given the contrasting distribution ranges of paniculate agaves, our results seem to support the trend from specialization to generalization along the continuum of tropical to extratropical deserts.
Pollination ecology of Stenocereus queretaroensis (Cactaceae), a chiropterophilous columnar cactus, in a tropical dry forest of Mexico
Flowers of columnar cacti are animal-pollinated, often displaying a chiropterophylic syndrome. This study examined if the columnar cactus Stenocereus queretaroensis, a tropical species endemic to western Mexico, is bat-pollinated, by studying its pollination biology and the foraging behavior of potential pollinators. Flowers were produced in winter through spring, peaking in April. Anthesis was nocturnal, and stigma and anther turgidity began around 2200 hours. Production of nectar secretion and highest sugar concentration and energy supply were nocturnal, peaking between 2200 and 2400 hours. Manual auto-pollination and exclusion experiments showed that self-pollination yielded no fruits, while nocturnal pollinators resulted in high fruit set and seed set compared to diurnal pollination treatments. The nectar-feeding bat Leptonycteris curasoae (Phyllostomidae) was the main nocturnal pollinator with the highest effective pollination. Peak bat visitation coincided with peaks in nectar production. The high abundance of L. curasoae throughout the 4-yr study, suggests that it is a seasonally reliable pollinator for this columnar cactus. While pollination syndromes have been increasingly called into question in recent years, this study suggests that at least for this system, there is a fairly close fit between pollinator and pollination syndrome.
Ambient temperature drives sex ratio and presence of pregnant females of Anoura geoffroyi (Phyllostomidae) bats living in temperate forests
Phenology in animals is strongly influenced by seasonality that promotes changes in abundance of food resources and temperature. These changes may impose energetic constraints to organisms in certain seasons during the year, especially on those animals facing high energetic demands, such as nectarivorous bats. Seasonality in temperate forests could, therefore, promote migration of female nectarivorous bat to find warmer sites, thus enhancing breeding success. To test this hypothesis, we compared the proportion of females and the proportion of pregnant females of the nectarivorous bat Anoura geoffroyi, between months, in six different populations across temperate forests of Mexico. Bats were captured over a complete season cycle either with sweep or mist nets at the entrance or near their roosting caves, and their age, sex, and reproductive condition were recorded. We found that over 50% of bats present in the cave roosts across different populations in temperate forests of the Trans-Mexican Neovolcanic Belt of Mexico during the warmer and wetter months (April–September) were females, both pregnant and nonpregnant. In contrast, fewer than 30% of bats present in the roosting caves sampled in the colder and drier months (October–March) were females. In addition, we found that the temperature that favors the proportion of females at the studied sites was greater than 8°C. We concluded that seasonality affects sex ratio and phenology of A. geoffroyi in Mexican temperate forests. Our findings suggest females' migrations to lowland warmer sites to improve prenatal development.
Pollination ecology of Agave macroacantha (Agavaceae) in a Mexican tropical desert. I. Floral biology and pollination mechanisms
In a study of sexual reproduction in long-lived semelparous plants, we observed Agave macroacantha in the tropical desert of Tehuacan-Cuicatlan, Mexico, describing duration of flowering, flower phenology, and nectar production patterns. We also performed two manipulative experiments evaluating (a) the seed production efficiency of different crossing systems (selfing, cross-pollination, apomixis, and control), and (b) the effect of different pollinators (diurnal exposure to pollinators, nocturnal exposure, exclusion, and control) on the seeds produced. Flowering occurred from early May to late July and had a mean duration of 29 days in the individual rosettes. The flowers were protandrous; anthesis occurred in the afternoon of the third day after floral opening, and the pistils matured in the afternoon of the fifth day. The stigmas remained receptive from dusk to the following morning. Pollination was mostly allogamous. Nectar was produced principally during the night, from the first stages of floral aperture until the stigmas wilted and flowering ceased. The flowers were visited during the day by hymenoptera, butterflies, and hummingbirds and during the night by bats and moths. Only the nocturnal visitors, however, were successful pollinators. Agave macroacantha is extremely dependent on nocturnal pollinators for its reproductive success.
Pollination ecology of Agave macroacantha (Agavaceae) in a Mexican tropical desert. II. The role of pollinators
We did a series of observational studies and manipulative experiments on the guild of nocturnal visitors of Agave macroacantha, including (1) a description of the hourly patterns of visits by moths and bats, (2) an evaluation of the relative contribution of bats and moths to flowering success, and (3) an evaluation of the pollination efficiency of the different bat species. Scapes exposed to moths but excluded to bats yielded ∼50% fewer fruits than those exposed to both pollinator groups. Flowers exposed to the bat species Leptonycteris curasoae showed similar fruiting success to those exposed to Choeronycteris mexicana and to those exposed to the whole nocturnal visitor guild. However, the fruits originated from flowers pollinated by Leptonycteris curasoae yielded significantly more seed than those exposed to Choeronycteris mexicana or to the whole pollinator guild. It is concluded that Agave macroacantha is extremely dependent on nocturnal pollinators for its reproductive success and that bats are especially important for successful pollination. Some of these pollinators are migratory and have been reported to be steadily declining. A continuing decline in the populations of pollinators may impede the successful sexual reproduction of the plant host and may put the long-term survival of this agave species under risk.
Pollination biology of two columnar cacti (Neobuxbaumia mezcalaensis and Neobuxbaumia macrocephala) in the Tehuacan Valley, central Mexico
We document the pollination biology and mating systems of Neobuxbaumia mezcalaensis and Neoburbaumia macrocephala, two Mexican giant columnar cacti. These two species form mixed forests in the western Tehuacan Valley, Mexico. The flowers of both N. mezcalaensis and N. macrocephala exhibit nocturnal anthesis, are self-incompatible, and are pollinated primarily by three species of nectar-feeding bats (Choeronycteris mexicana, Leptonycteris curasoae, and Leptonycteris nivalis). Neobuxbaumia mezcalaensis is androdioecious, a breeding system that appears to be uncommon among Cactacese. Neobuxbaumia macrocephala is hermaphroditic. We hypothesize that columnar cacti show a geographical dichotomy in floral biology specialization that probably can be related to predictability in pollinator abundance
New records on distribution and habitat of the lesser long-nosed bat (Leptonycteris yerbabuenae) in Honduras
The lesser long-nosed bat ( Leptonycteris yerbabuenae Martínez & Villa-R, 1940) is a specialized nectar feeding species found from southern USA to Nicaragua in Central America, mostly in dry forest. We sampled bats using mist nets and Anabat detectors, and also looked for them at refuges and other sites in Honduras from 2011 to 2016. The lesser long-nosed bat is known in Honduras from only two localities in the southern dry forests below 100 m elevation, and there are no recent records of this species in the country. Our objective is to report new records on distribution and habitat of the lesser long-nosed bat in Honduras. We found eight lesser long-nosed bats at Cerro de Hula, Francisco Morazán department in 2012, and 10 at La Anonilla, Choluteca department, southern Honduras in 2015. Based on these 18 individuals of the lesser long-nosed bat, we report two new localities in Honduras, an altitude record, and the use of another habitat other than the dry forest. The highest point registered was at 1710 m a.s.l. in pastureland with forest remnants in an area heavily impacted by human activities. The new localities are found in the Subtropical Moist Forest. Populations of long-nosed bats in Honduras are probably resident and may include altitudinal movements. Although this species has been described widely in North America, its behavior in Honduras is practically unknown. It is a key species for the tequila and mezcal industry, but its range extends beyond the tequila production area, where it maintains a key role as a pollinator and link between habitats. As a result, research and conservation efforts should be an international goal.
Seasonal intake responses in the nectar-feeding bat Glossophaga soricina
Food intake in nectar-feeding animals is affected by food quality, their energetic demands, and the environmental conditions they face. These animals increase their food intake in response to a decrease in food quality, a behavior named “intake response”. However, their capacity to achieve compensatory feeding, in which they maintain a constant flux of energy, could be constrained by physiological processes. Here we evaluated how both a seasonal change in environmental conditions and physiological constraints affected the food ingestion in the bat Glossophaga soricina . We measured food intake rate during both the wet/warm and dry/cool seasons at sucrose solutions ranging from 146 to 1,022 mmol L −1 . We expected that food intake and metabolic demands would be greater during the dry/cool season. Bats ingested ~20% more food in the dry/cool than in the wet/warm season. Regardless of season, bats were unable to achieve a constant flux of energy when facing the different sugar concentrations that we used in our experiments. This suggests that the rate of food intake is physiologically constrained in G. soricina . Using the digestive capacity of bats we modeled their food intake. The analytic model we used predicts that digestive limitations to ingest energy should have an important effect on the ecology of this species.