Record Of Bat Research Articles

Van Gelder's Bat (Bauerus dubiaquercus) from El Salvador, Central America

Abstract We report the first record of Van Gelder's bat (Bauerus dubiaquercus) from El Salvador, Central America. This is the first report of Van Gelder's bat from the Pacific versant of Mesoamerica, between Guerrero, Mexico, and Costa Rica, a distance of ca. 1,850 km.

Records of Bats from Oaxaca, Mexico

Abstract During a survey of small mammals in the municipality of Santa Maria Chimalapa in eastern Oaxaca, Mexico, we obtained the first record of Thomas' shaggy bat (Centronycteris centralis, Vespertilionidae) and the funnel-eared bat (Natalus lanatus, Natalidae), as well as the second record of the false vampire bat (Vampyrum spectrum, Phyllostomidae) for the state. With these new records, the list of bats for Oaxaca increased to 86 species, confirming Oaxaca as the Mexican state with the greatest number of species of terrestrial mammals and, in particular, the Chimalapas region as one of the most diverse regions in the country.

First record of Bechstein's bat (Myotis bechsteinii Kuhl, 1817) at north of Portugal and new specie for the Site of Communitary Importance Alvão-Marão

First record of Bechstein's bat (Myotis bechsteinii Kuhl, 1817) at north of Portugal and new specie for the Site of Communitary Importance Alvão-Marão

Determinants of echolocation call frequency variation in the Formosan lesser horseshoe bat (Rhinolophus monoceros).

The origin and maintenance of intraspecific variation in vocal signals is important for population divergence and speciation. Where vocalizations are transmitted by vertical cultural inheritance, similarity will reflect co-ancestry, and thus vocal divergence should reflect genetic structure. Horseshoe bats are characterized by echolocation calls dominated by a constant frequency component that is partly determined by maternal imprinting. Although previous studies showed that constant frequency calls are also influenced by some non-genetic factors, it is not known how frequency relates to genetic structure. To test this, we related constant frequency variation to genetic and non-genetic variables in the Formosan lesser horseshoe bat (Rhinolophus monoceros). Recordings of bats from across Taiwan revealed that females called at higher frequencies than males; however, we found no effect of environmental or morphological factors on call frequency. By comparison, variation showed clear population structure, with frequencies lower in the centre and east, and higher in the north and south. Within these regions, frequency divergence was directional and correlated with geographical distance, suggesting that call frequencies are subject to cultural drift. However, microsatellite clustering analysis showed that broad differences in constant frequency among populations corresponded to discontinuities in allele frequencies resulting from vicariant events. Our results provide evidence that the processes shaping genetic subdivision have concomitant consequences for divergence in echolocation call frequency.

Global Completeness of the Bat Fossil Record

Bats are unique among mammals in their use of powered flight and their widespread capacity for laryngeal echolocation. Understanding how and when these and other abilities evolved could be improved by examining the bat fossil record. However, the fossil record of bats is commonly believed to be very poor. Quantitative analyses of this record have rarely been attempted, so it has been difficult to gauge just how depauperate the bat fossil record really is. A crucial step in analyzing the quality of the fossil record is to be able to accurately estimate completeness. Measures of completeness of the fossil record have important consequences for our understanding of evolutionary rates and patterns among bats. In this study, we applied previously developed statistical methods of analyzing completeness to the bat fossil record. The main utility of these methods over others used to study completeness is their independence from phylogeny. This phylogenetic-independence is desirable, given the recent state of flux in the higher-level phylogenetic relationships of bats. All known fossil bat genera were tabulated at the geologic stage or sub-epoch level. This binning strategy allowed an estimate of the extinction rate for each bat genus per bin. Extinction rate—together with per-genus estimates of preservation probability and original temporal distributions—was used to calculate completeness. At the genus level, the bat fossil record is estimated to be 12% complete. Within the order, Pteropodidae is missing most of its fossil history, while Rhinolophoidea and Vespertilionoidea are missing the least. These results suggest that 88% of bats that existed never left a fossil record, and that the fossil record of bats is indeed poor. Much of the taxonomic and evolutionary history of bats has yet to be uncovered.

Quantifying bat call detection performance of humans and machines

Methods for detecting echolocation calls in field recordings of bats vary in performance and influence the effective range of a recording system. In experiments using synthetic calls from five species, human detection accuracy was 89.7+/-0.6%, compared to 76.3+/-0.8% for a model-based detector, 72.2+/-0.8% for an energy-based detector, and 98.4+/-0.2% for an optimal linear detector. The energy-based detector was 11 times faster than the model-based detector and 110 times faster than humans. Human accuracy was positively correlated with test duration (R(2)=0.43, P<0.05), meaning that higher accuracy was achieved at the expense of slower performance. Species was a significant factor determining accuracy for all detectors (P<0.001) because of call bandwidth: Narrowband calls concentrated energy in a narrower frequency band and were easier to detect. For a hypothetical recording system, range at 90% human detection accuracy varied from 10 to 35 m among species, while range dropped by approximately 20% using the automated detectors. The optimal detector outperformed humans by 5 dB and the automated methods by 9 dB. The results quantify the tradeoff between detector speed and accuracy and are useful for designing field studies of bats.

Noteworthy Records of Bats from Central Georgia

On the basis of published records, 16 bat species occur in Georgia. Of these, only one species is documented from Baldwin County in central Georgia, but records from surrounding counties suggest the likelihood of additional species inhabiting the county. On the basis of museum specimens in the mammal collection of Georgia College and State University, we report seven species of bats inhabiting the county: Perimyotis subflavus (Eastern Pipistrelle), Nycticeius humeralis (Evening Bat), Lasiurus borealis (Red Bat), Lasiurus seminolus (Seminole Bat), Eptesicus fuscus (Big Brown Bat), Myotis austroriparius (Southeastern Myotis), and Tadarida brasiliensis (Brazilian Free-tailed Bat). With the exception of the Brazilian Free-tailed Bat, the specimens represent first records from Baldwin County. Moreover, the records significantly add to the general baseline information of species richness and distribution of bats in central Georgia, and they help fill distribution gaps in this part of the southeastern United States.

Primitive Early Eocene bat from Wyoming and the evolution of flight and echolocation

Bats (Chiroptera) represent one of the largest and most diverse radiations of mammals, accounting for one-fifth of extant species. Although recent studies unambiguously support bat monophyly and consensus is rapidly emerging about evolutionary relationships among extant lineages, the fossil record of bats extends over 50 million years, and early evolution of the group remains poorly understood. Here we describe a new bat from the Early Eocene Green River Formation of Wyoming, USA, with features that are more primitive than seen in any previously known bat. The evolutionary pathways that led to flapping flight and echolocation in bats have been in dispute, and until now fossils have been of limited use in documenting transitions involved in this marked change in lifestyle. Phylogenetically informed comparisons of the new taxon with other bats and non-flying mammals reveal that critical morphological and functional changes evolved incrementally. Forelimb anatomy indicates that the new bat was capable of powered flight like other Eocene bats, but ear morphology suggests that it lacked their echolocation abilities, supporting a 'flight first' hypothesis for chiropteran evolution. The shape of the wings suggests that an undulating gliding-fluttering flight style may be primitive for bats, and the presence of a long calcar indicates that a broad tail membrane evolved early in Chiroptera, probably functioning as an additional airfoil rather than as a prey-capture device. Limb proportions and retention of claws on all digits indicate that the new bat may have been an agile climber that employed quadrupedal locomotion and under-branch hanging behaviour.

Link-based feature extraction for model-based detection of echolocation calls

Frame-based acoustical analysis of echolocation calls from bats has recently been proposed to improve the robustness of automated call detection. Statistical models, popularized and honed by automated human speech processing research, learn the distributions of call features extracted identically from short overlapping frames of time. A fundamental assumption is that each frame contains at most one echolocation call. In field recordings of bats, this assumption is often violated by the presence of echoes and overlapping calls from multiple bats, which degrade automated detection performance. Simple rules, based on expert knowledge of echolocation calls, were used to follow local spectrogram ridges and to group ridge points into links. Frame-based features were extracted from the links, which may overlap in time, allowing links to be used in the existing model-based analysis paradigm. Improved performance using links is demonstrated for several pathological cases, including conspecific interaction and high-duty-cycle foraging.

High bat (Chiroptera) diversity in the Early Eocene of India

The geographic origin of bats is still unknown, and fossils of earliest bats are rare and poorly diversified, with, maybe, the exception of Europe. The earliest bats are recorded from the Early Eocene of North America, Europe, North Africa and Australia where they seem to appear suddenly and simultaneously. Until now, the oldest record in Asia was from the Middle Eocene. In this paper, we report the discovery of the oldest bat fauna of Asia dating from the Early Eocene of the Cambay Formation at Vastan Lignite Mine in Western India. The fossil taxa are described on the basis of well-preserved fragments of dentaries and lower teeth. The fauna is highly diversified and is represented by seven species belonging to seven genera and at least four families. Two genera and five species are new. Three species exhibit very primitive dental characters, whereas four others indicate more advanced states. Unexpectedly, this fauna presents strong affinities with the European faunas from the French Paris Basin and the German Messel locality. This could result from the limited fossil record of bats in Asia, but could also suggest new palaeobiogeographic scenarios involving the relative position of India during the Early Eocene.

Northern Long-eared Bat, &lt;em&gt;Myotis septentrionalis&lt;/em&gt; (Chiroptera: Vespertilionidae), on Prince Edward Island: First Records of Occurrence and Over-Wintering

First occurrence of the Northern Long-eared Bat, Myotis septentrionalis, on Prince Edward Island is reported. A mixed-species hibernaculum of M. septentrionalis and the Little Brown Bat, M. lucifugus, is also described from southeastern Prince Edward Island. This is the first record of bats over-wintering in the province and the first time either species has been reported making use of a building as a hibernaculum.

Record of bats from Kochi Prefecture: Forest-dwelling bats caught by mist nets (Ⅱ)

Record of bats from Kochi Prefecture: Forest-dwelling bats caught by mist nets (Ⅱ)

北海道十勝・日高地方の翼手類相(6) : 帯広市農耕地域の防風保安林における捕獲記録

北海道十勝・日高地方の翼手類相(6) : 帯広市農耕地域の防風保安林における捕獲記録

The First Record of Late Miocene Bat from European Russia

A single bone fragment of a Vespertilionine bat was discovered in the rich Late Turolian (MN12-13) vertebrate fauna of Morskaya 2 site near Taganrog (Sea of Azov re- gion). This is the first record of bat remains from Late Miocene deposits of the European Russia. The morphology of the discovered fossil, represented by mandibular fragment with two molars, resembles the recent genera Vespertilio and Eptesicus. Comparative analysis with recent and fossil species of these two taxa allows us to assign this fossil to Vespertilio cf. villanyiensis.

Bat fauna in Hidaka and Tokachi districts, central and eastern Hokkaido (7) : Capture record of bats in the Inada and Kawanishi areas of Obihiro City

Bat fauna in Hidaka and Tokachi districts, central and eastern Hokkaido (7) : Capture record of bats in the Inada and Kawanishi areas of Obihiro City

Bats fauna in Hidaka and Tokachi districts, central and eastern Hokkaido (4) : Records of bats in Shihoro River and Osarushinai River, in central Tokachi

Bats fauna in Hidaka and Tokachi districts, central and eastern Hokkaido (4) : Records of bats in Shihoro River and Osarushinai River, in central Tokachi

Record of bats from Kochi Prefecture : Woodland bats caught by mist nets

Record of bats from Kochi Prefecture : Woodland bats caught by mist nets

Bats fauna of Hidaka and Tokachi districts, central and south-eastern Hokkaido : (2) Records of bats in Meto area, Ashoro, north-eastern Tokachi

Bats fauna of Hidaka and Tokachi districts, central and south-eastern Hokkaido : (2) Records of bats in Meto area, Ashoro, north-eastern Tokachi

Records of bats in Akan and Shiranuka towns, eastern Hokkaido

Records of bats in Akan and Shiranuka towns, eastern Hokkaido

New Records of Bats from Nagaland, India

New Records of Bats from Nagaland, India