Myotis Vivesi Research Articles

ISOLATION OF ENTERIC PATHOGENS FROM BATS IN TRINIDAD

Bats are one of the most widely distributed mammals in the world, and they are reservoirs or carriers of several zoonoses. Bats were trapped in 27 geographic locations across Trinidad and Tobago, and following euthanasia, gastrointestinal tracts were aseptically removed. Contents were subjected to bacteriologic analysis to detect Salmonella spp., Escherichia coli, and Campylobacter spp. Isolates of Salmonella were serotyped, and E. coli isolates were screened for O157 strains and antimicrobial sensitivity to eight antimicrobial agents; phenotypic characteristics also were determined. Of 377 tested bats, representing 12 species, four bats (1.1%) were positive for Samonella spp, 49 (13.0%) were positive for E. coli, and no bats were positive for E. coli O157 strain or Campylobacter spp. Isolated serotypes of Salmonella included Rubislaw and Molade, both from Noctilio leporinus, a fish-eating bat, Caracas recovered from Molossus major, and Salmonella Group I from Molossus ater, both insect-eating bats. Of the 49 isolates of E. coli tested, 40 (82%) exhibited resistance to one or more antimicrobial agents, and the prevalence of resistant strains was comparatively high to erythromycin (61%) and streptomycin (27%) but lower to gentamycin (0%) and sulphamethozaxole/trimethoprim (2%).

Conserving the endangered Mexican fishing bat (Myotis vivesi): genetic variation indicates extensive gene flow among islands in the Gulf of California

The endangered Mexican fishing bat, Myotis vivesi, appears to have suffered widespread extinction and population decline on islands throughout the Gulf of California, largely due to predation by introduced cats and rats. To restore populations of fishing bats and other native species, conservation efforts have focused on eradicating introduced vertebrates from several Gulf islands. These efforts assume that individuals from existing populations will recolonize islands and that continued dispersal will help sustain vulnerable populations thereafter. However, the extent of inter-island dispersal in fishing bats is unknown. In this study we analyzed patterns of genetic variation to gauge the extent of gene flow and, thus, potential dispersal among islands. DNA was sampled from 257 fishing bats on 11 Gulf islands (separated by ca. 6–685 km of open water), and individuals were genotyped at six microsatellite loci and haplotyped at a 282 bp fragment of the mtDNA control region. With microsatellites, we found weak population genetic structure and a pattern of isolation by distance, while with mtDNA we found strong structure but no isolation by distance. Our results indicate that island subpopulations separated by large expanses of open water are nonetheless capable of maintaining high genetic diversity and high rates of gene flow. Unfortunately, little is known about the spatial patterns of dispersal or mating system of fishing bats, and these behavioral factors, in particular female philopatry, might reduce the probability of the species recolonizing Gulf islands.

Patterns of island occupancy in bats: influences of area and isolation on insular incidence of volant mammals

ABSTRACTAim The influence of landscape structure on the distribution patterns of bats remains poorly understood for many species. This study investigates the relationship between area and isolation of islands and the probability of occurrence of six bat species to determine whether persistence and immigration abilities vary among bat species and foraging guilds.Location Thirty‐two islands in the Gulf of California near the Baja California peninsula in north‐west Mexico.Methods Using logistic regression and Akaike information criterion (AIC) model selection, we compared five a priori models for each of six bat species to explain patterns of island occupancy, including random patterns, minimum area effects, maximum isolation effects, additive area and isolation effects and compensatory area and isolation effects.Results Five species of insectivorous bats (Pipistrellus hesperus, Myotis californicus, Macrotus californicus, Antrozous pallidus and Mormoops megalophylla) displayed minimum area thresholds on incidence. The probability of occurrence tended to decrease at moderate distances of isolation (c. 10–15 km) for these species (excepting A. pallidus). The distributions of two non‐insectivorous species (Leptonycteris curasoae and Myotis vivesi) were not influenced by island size and isolation.Main conclusions Minimum area thresholds on incidence suggest that island occupancy by insectivorous bats may be limited by resource requirements. Islands smaller than 100 ha typically did not support occupancy or use by insectivorous bats, except at minimal isolation distances. Insectivorous bat species may also be more sensitive to moderate levels of habitat isolation in some landscape contexts than previously expected. Our results suggest that differences in foraging habits may have important implications for understanding the distribution patterns of bats.

ENDEMIC AND INTRODUCED VERTEBRATES IN THE DIET OF THE BARN OWL (TYTO ALBA) ON TWO ISLANDS IN THE GULF OF CALIFORNIA, MEXICO

Through the analysis of 458 barn owl (Tyto alba) pellets collected between 1981 and 1995 on 2 islands in the northern Gulf of California, Mexico, we found significant differences in the main components of the diet of barn owls on these islands, where introduced rodents, bats, and seabirds occur. On Rasa Island, the most important prey was Rattus rattus, followed by Myotis vivesi, Oceanodroma microsoma, Mus musculus, and 4 bird species. On Partida Island, the main prey was M. vivesi, followed by O. microsoma, R. rattus, and 3 bird species. The mean number of prey per pellet was higher on Partida Island (1.08) than on Rasa Island (0.91), but the mean biomass per pellet was higher on Rasa Island (75.8 g) than on Partida Island (25.8 g). The storm-petrels O. microsoma and O. melania were taken by barn owls in proportion to their abundance on both islands. Conversely, barn owls on Rasa Island ate more R. rattus than M. musculus, possibly because of the larger size of the former. Overall, our data suggest that barn owls in the Gulf of California behave as flexible predators that take prey according to availability and profitability.

Molecular Systematics of the Fishing Bat Myotis (Pizonyx) vivesi

Phylogenetic reconstructions based on molecular data have shown recurrent morphological convergence during evolution of the species-rich genus Myotis. Species or groups of species with similar feeding strategies have evolved independently several times to produce remarkable similarities in external morphology. In this context, we investigated the contentious phylogenetic position of 1 of the 2 piscivorous bat species, Myotis vivesi, which was not included in previous molecular studies. This bat, endemic to the coasts and islands of the Gulf of California, Mexico, was long classified in its own genus, Pizonyx, because of its distinctive morphology. To reconstruct its phylogenetic origins relative to other Myotis, we sequenced the mitochondrial cytochrome-b gene of 2 M. vivesi and related vespertilionids. These outgroups included Pipistrellus subflavus, a member of the subgenus Perimyotis, sometimes classified within the genus Myotis. Unexpectedly, all reconstructions placed M. vivesi within a strongly supported clade including all other typical neotropical and Nearctic Myotis. This molecular phylogeny supports an endemic radiation of New World Myotis. Other Myotis species with similar adaptations to gaffing prey from the water surface present no close phylogenetic relationships with M. vivesi, indicating that such adaptations are convergences. On the other hand, P. subflavus is genetically as distant from the genus Myotis as from other Pipistrellus species, suggesting that generic rank to Perimyotis is warranted.

Dietary analysis confirms that Rickett's big‐footed bat (Myotis ricketti) is a piscivore

AbstractThe diet of Myotis ricketti was examined by faecal analysis, and foraging behaviour was observed in the field. Scales from at least three species of small fish were found in the droppings, together with fragments of insects from six orders. This study demonstrates that M. ricketti is a fish‐eating bat. As with other trawling bats in the genus Myotis, M. ricketti emits short, broadband echolocation sounds. The sounds recorded from bats released from the hand swept downward from c. 70 to 28 kHz in 4 ms, and contained most energy at 41 kHz.

Six New Eimeria Species from Vespertilionid Bats of North America

Twenty species of bats (Molossidae, Vespertilionidae) were collected from California, New Mexico, Oregon, South Carolina, Utah, and Baja California Norte (Mexico), and 29 of 404 (7%) animals, including Antrozous pallidus, Eptesicus fuscus, Myotis auriculus, Myotis californicus, Myotis ciliolabrum, Myotis evotis, Myotis lucifugus, Myotis thysanodes, Myotis vivesi, Myotis volans, Myotis yumanensis, and Nycticeius humeralis were infected with Eimeria spp., which represent 6 new species. Sporulated oocysts of a new species from A. pallidus are subspheroidal, 24.8 x 21.6 (22-27 x 19-24) microm with a polar granule and a large globular residuum. The oocyst wall is sculptured, with 2 layers, approximately 1.5 thick. Ovoidal sporocysts are 11.5 x 7.8 (9-13 x 7-10) microm, with Stieda body and residuum of many large granules. Sporulated oocysts of a new species from M. californicus are subspheroidal, 20.7 x 18.2 (19-23 x 16-20) microm, with 1-7 tiny polar granules, but without oocyst residuum. The oocyst wall is rough, with 2 layers, approximately 1.4 thick. Ovoidal sporocysts are 11.2 x 7.3 (10-12 x 7-8) microm, with Stieda body and a globular residuum. Sporulated oocysts of a second new species from M. californicus are subspheroidal, 23.1 x 20.7 (20-26 x 19-23) microm, with residuum and 1 polar granule, but a micropyle is absent. The oocyst wall is rough with 2 layers, approximately 1.5 thick. Ovoidal sporocysts are 12.5 x 7.2 (11-14 x 7-8) microm, with a Stieda body and residuum. Sporulated oocysts of a new species from M. ciliolabrum are subspheroidal, 24.9 x 20.1 (18-27 x 17-23) microm, with 1-2 polar granules, but without micropyle and residuum. The oocyst wall is rough with 2 layers, approximately 1.5 thick. Ellipsoidal sporocysts are 12.5 x 9.0 (8-14 x 7-10) microm, with Stieda and substieda bodies and residuum. Sporulated oocysts of a new species from M. evotis are subspheroidal, 21.3 x 18.6 (20-24 x 15-20) microm, with a prominent polar granule, but without micropyle and residuum. The oocyst wall is smooth with 2 layers, approximately 1.0 thick. Ovoidal sporocysts are 12.2 x 8.0 (11-13 x 7.5-9) microm, with Stieda and substieda bodies and residuum. Sporulated oocysts of the new species from N. humeralis are subspheroidal, 22.4 x 18 (21-24 x 17-20) microm, with 1-3 polar granules, but residuum and micropyle are absent. The oocyst wall is lightly sculptured with 2 layers, approximately 1.4 thick. Ovoidal sporocysts are 10.9 x 7.7 (9-12 x 6-8) microm, with Stieda body and residuum. Sporulated oocysts of E. pilarensis Scott and Duszynski, 1997 and those of at least 12 other morphological forms were seen in the other infected bats; these latter forms were seen in too few numbers to be adequately described as new species.

Pizonyx wheeleriDalquest and Patrick (Mammalia: Chiroptera) from the Miocene of Texas referred to the genusAntrozousH. Allen

(1993). Pizonyx wheeleri Dalquest and Patrick (Mammalia: Chiroptera) from the Miocene of Texas referred to the genus Antrozous H. Allen. Journal of Vertebrate Paleontology: Vol. 13, No. 3, pp. 378-380.

Hydrodynamics of the feet of fish‐catching bats: Influence of the water surface on drag and morphological design

AbstractThe bats, Noctilio leporinus and Pizonyx vivesi, display similar hind foot morphologies specialized for their fish‐catching habits. The hydrodynamic drag force of isolated hind feet from fishing and closely related non‐fishing bats was measured in a water channel at velocities up to 0.74 ms−1. Drag force increased curvilinearly with increasing water velocity. The highest values of drag force for a given velocity were measured for the fishing bats, which have hind feet 1.8–3.9 times larger than related non‐fishing bats. However at high Froude Numbers, the dimensionless drag coefficient (CD) was 23–39% lower for fishing bats compared to non‐fishing bats. Cross‐sections of the laterally compressed toes of N. leporinus and P. vivesi conformed to hydrofoil designs with minimum drag capabilities, indicated by Fineness Ratio and shoulder position. Moveing at high Froude Numbers at the water surface results in the addition of spray drag to the other components of the total drag force (i.e., frictional, pressure, and wave). Spray drag is suppressed by a foil shape with a long pointed leading edge with a short rounded trailing edge. The configuration of the fishing bat toe with a sharp leading edge and relatively long forebody region compared to the maximum thickness provided a measurable drag reduction at the air‐water interface. It was concluded that hydrodynamic drag considerations at the water surface were important in the design of hind feed for fish‐catching bats.

Salt and water metabolism in the marine fish-eating bat, Pizonyx vivesi

1. 1. Water loss and salt excretion were measured in Pizonyx vivesi, a desert bat which feeds on marine crustacea and fish. 2. 2. Evaporative water losses were higher than those of other mammals, but were considerably reduced when bats were torpid. 3. 3. P. vivesi can concentratel saltes in the urine sufficiently to utilize sea water as a water source. 4. 4. Calculation of the complete water budget indicates with P. vivesi probably requires sea water to maintain water balance. 5. 5. Data on salt content of the bat's diet suggest that, with low evaporative losses, other marine mammals can obtain all necessary water from a diet of crustacea only, without utilizing sea water.

Comparative Echolocation by Fishing Bats

The acoustic orientation of two species of fish-catching bats was studied as they negotiated a row of strings or fine wires extending across their flight path. Orientation sounds of Pizonyx vivesi consisted of a steep descending FM sweep lasting about 3 msec. Noctilio leporinus used 8 to 10 msec pulses composed of an initial nearly constant frequency portion followed by a descending frequency modulation. The echolocation of small wires by N. leporimis differed from that of surface fish in that during wire avoidance no nearly constant frequency or entirely FM pulses were emitted, nor was the pulse duration markedly shortened as the barrier was approached. There was extensive temporal overlap at the animal's ear of returning echoes with the emitted cries when the bat was near the barrier—a strong contrast to the apparent careful minimization of such overlap during feeding maneuvers. Noctilio increased its average pulse duration about 2 msec when confronted with a barrier of 0.21 mm, as opposed to 0.51 mm, diameter wires. Pizonyx detected these wires well before pulse-echo overlap began, but at a shorter range than did N. leporinus, suggesting the latter species may have a longer effective range of echolocation.

Oxygen consumption, temperature, and water loss in bats from different environments.

Oxygen consumption, temperature, and water loss in bats from different environments.

Keeping Bats in Captivity

During the past ten years the writer, assisted by Mary Louise Perry, Berta B. Kessel and Jacqueline Schonewald, has been keeping bats in captivity for purposes of study. As a result, certain techniques have been developed which may be of use to others who find it necessary to maintain these animals for research. Several hundred bats representing 12 species were kept for periods varying from months to years. The species involved were: little brown myotis ( Myotis lucifugus ), Yuma myotis ( M. yumanensis ), fringed myotis ( M. thysanodes ), Indiana myotis ( M. sodalis ), California myotis ( M. californicus ), Mexican fish-eating bat ( Pizonyx vivesi ), big brown bat ( Eptesicus fuscus ), red bat ( Lasiurus borealis ), hoary bat ( L. cinereus ), western lump-nosed bat ( Corynorhinus rafinesquii ), pallid bat ( Antrozous pallidus ) and Mexican free-tail bat ( Tadarida mexicana ). All individuals except those belonging to two species were secured in northern or central California. The Indiana myotis were captured by Wayne H. Davis in West Virginia and the fish-eating bats by Prentice Bloedel near Guaymas, Sonora, Mexico. Field methods .—Before discussing the care of bats in the laboratory a few suggestions might be in order regarding the capture of these animals in the field for live study. Considerable care should be exerted to avoid injuring bats at such times. Although they are rather hardy creatures, an injured individual has less chance of survival than one that has not been hurt. Most bat collectors make use of long-handled insect nets and long forceps (10–12 inches) for catching bats in daytime roosts. Dexterity in the use of both these tools is a great advantage. The net should not be used as a fly swatter to produce concussion which may ultimately cause death nor should forceps be used in such a way as to tear flight membranes or cause dislocations. Another method of collecting bats involves …

Distribution, Type Locality, and Habits of the Fish-Eating Bat, Pizonyx vivesi

Distribution, Type Locality, and Habits of the Fish-Eating Bat, Pizonyx vivesi

Respiratory Water Loss in Some Birds of Southwestern United States

Respiratory Water Loss in Some Birds of Southwestern United States

General Notes

The Fish-Eating Habits of Pizonyx Vivesi (Menegaux) William Henry Burt William Henry Burt California Institute of Technology, Pasadena, California Search for other works by this author on: Oxford Academic Google Scholar Journal of Mammalogy, Volume 13, Issue 4, 2 November 1932, Pages 363–365, https://doi.org/10.2307/1374142 Published: 02 November 1932