@article {58054, title = {Contribution of acoustic methods to the study of insectivorous bat diversity in protected areas from northern Venezuela }, journal = {Acta ChiropterologicaActa Chiropterologica}, volume = {2}, number = {2}, year = {2000}, pages = {171-183}, abstract = {We present the results of an acoustic survey of aerial insectivorous bats conducted in four protected areas in
northern Venezuela. These areas represent localities where the taxonomic composition of the bat communities
was relatively well known. We conducted field surveys using the Anabat II detector and analysis system. We
compared acoustic inventories with previous lists obtained with conventional sampling methods (principally
mist nets). We identified 30 species acoustically (representing 15 genera of the families Emballonuridae,
Noctilionidae, Mormoopidae, Vespertilionidae, and Molossidae) on the basis of vocal signatures. Nineteen of
these were verified by capture and subsequent recording of released animals; the remainder were identified by
comparison with verified vocalizations from other localities. An additional 11 unidentified but distinct taxa
were recorded and are referred to here as {\textquoteright}sonotypes{\textquoteright} (based on similarities in call structure to known species)
representing eight genera of the families Emballonuridae, Vespertilionidae, and Molossidae. The short-term
acoustic surveys nearly equaled or exceeded the known species richness at three ofthe four localities, and added
two to nine species to previous lists from all locations; many of these bats correspond to taxa difficult to detect
with conventional capture methods.}, keywords = {acoustic survey, Anabat, community inventory, insectivorous bats, Neotropics, protected areas, sonotypes, technique comparison, Venezuela}, author = {Ochoa, Jos{\'e} and O{\textquoteright}Farrell, Michael J. and Miller, Bruce W.} } @article {58053, title = {A New Examination of Echolocation Calls of Some Neotropical Bats (Emballonuridae and Mormoopidae)}, journal = {Journal of MammalogyJournal of Mammalogy}, volume = {87}, number = {3}, year = {1997}, pages = {954-963}, abstract = {

In northwestern Belize, two emballonurids Rhynchonycteris naso and Saccopteryx bilineata) and three mormoopids Pteronotus parnellii, P. davyi, and P. personatus) were examined acoustically with the Anabat II bat detector and associated analysis system. R. naso used calls consisting of a short constant frequency CF) at 47 kHz and concave downward frequency modulated FM) sweep to about 40 kHz with two strong harmonics. Echolocation sequences of S. bilineata revealed a paired cadence of calls. Both signals in a pair slowly increased in frequency, forming a quasi-CF QCF) component and terminated with a short, downward FM sweep. The initial call of a pair ranged from 44.5 to 46.6 kHz and the second ranged from 46.6 to 48.7 kHz. P. parnellii used a long CF call at 63.5 kHz, with a terminal downward FM sweep to about 54.5 kHz. P. davyi produced calls with an initial short CF at 68.1 kHz, a downward FM sweep, and a terminal short CF at 58.0 kHz. P. personatus emitted calls similar in shape to P. davyi, with the initial CF at 83.0 kHz and the terminal CF at about 68.0 kHz. Previous descriptions of echolocation calls for these species compare favorably with those obtained in this study, but the Anabat equipment generally revealed more variation and detail than previously described. The echolocation calls described in this study provide precise vocal signatures for the accurate identification of free-flying individuals of the species studied.

}, keywords = {Anabat, bats, echolocation, Pteronotus davyi, Pteronotus parnellii, Pteronotus personatus, Rhynchonycteris naso, Saccopteryx bilineata, vocal signatures}, author = {O{\textquoteright}Farrell, Michael J. and Miller, Bruce W.} } @article {58052, title = {Use of vocal signatures for the inventory of free-flying Neotropical bats}, journal = {BiotropicaBiotropica}, volume = {31}, number = {3}, year = {1999}, pages = {507-516}, abstract = {

An ongoing study is being conducted to test the efficacy of the Anabat II detector and analysis system in obtaining reliable vocal signatures for the identification of non-phyllostomid species of bats. We sampled a wide range of elevations and associated habitat types throughout Belize. Anabat provides an instantaneous output of echolocation call structure with a laptop computer. Select sequences can be saved directly to the hard drive, avoiding extraneous noise and sound distortion commonly associated with tape recorders. To date, 18 of the 37 species known or expected
to occur in the study region were identified by recognizable differences in the time-frequency characteristics of echolocation calls. In general, each family is recognizable by call structure patterns and species readily separated by frequency range parameters. Species that commute or forage at high altitudes are not susceptible to capture but are conspicuous by acoustic sampling. Further work is needed to determine limitations of the equipment, establish better sampling procedures, and develop a comprehensive library of vocal signatures incorporating the range of variation
inherent in each species. As this work progresses, we predict the addition of hitherto unknown species occurring within the study region.

}, keywords = {acoustic identification, Anabat, bats, Bauerus dubiaquercus, Chiroptera, diversity assessment, Emballonuridae, Eptesicus furinalis, inventory, Mormoopidae, Mormoops megalophylla, Myotis elegans, Neotropics, Noctilio leporinus, Pteronotus davyi, Pteronotus parnellii, Pteronotus personatus, Rhogeessa tumida, Saccopteryx bilineata, Saccopteryx leptura}, author = {O{\textquoteright}Farrell, Michael J. and Miller, Bruce W.} } @article {58051, title = {Qualitative Identification of Free-flying Bats Using the Anabat Detector}, journal = {Journal of MammalogyJournal of Mammalogy}, volume = {80}, number = {1}, year = {1999}, note = {JRS}, pages = {11-23}, abstract = {

A variety of ultrasonic bat detectors have been used over the past 3 decades to identify freeflying bats. Analyses of recorded echolocation calls were slow and typically restricted to few calls and at a resolution obscuring details of call structure. The Anabat II detector and associated zerocrossings analysis system allows an immediate examination, via a laptop computer, of the timefrequency structure of calls as they are detected. These calls can be stored on the hard drive for later examination, editing, and measurement. Many North American bats can be identified to species by qualitatively using certain structural characteristics of calls, primarily approximate maximum and minimum frequencies and morphological aspects of calls e.g., linearity and changes in slope). To identify calls precisely, it is important to use a continuous sequence of calls from an individual in normal flight rather than from single isolated calls. All calls are not equally useful, and many fragmentary calls must be discarded before making a determination. Each sequence of calls must be examined to ensure that multiple bats have not been simultaneously recorded, which confounds correct identification. We found the percentage of nonusable calls within usable vocal sequences to be highest in vespertilionids 20-40\%), whereas for other families this was frequently \<10\%. Active rather than passive collection of data maximizes quality and quantity of diagnostic calls and provides a contextual base for the investigator.

}, keywords = {Anabat, bats, Chiroptera, echolocation, Eptesicus furinalis, identification, Lasionycteris noctivagans, Lasiurus cinereus, Lasiurus ega, Molossus ater, Molossus molossus, Molossus sinaloae, Myotis californicus, Myotis ciliolabrum, Myotis yumanensis, Noctilio leporinus, Saccopteryx bilineata, Tadarida brasiliensis, technique, vocal signatures}, author = {O{\textquoteright}Farrell, Michael J. and Miller, Bruce W. and Gannon, William L.} } @article {58050, title = {A method for determining relative activity of free flying bats using a new activity index for acoustic monitoring}, journal = {Acta ChiropterologicaActa Chiropterologica}, volume = {3}, number = {1}, year = {2001}, pages = {93-105}, abstract = {

A new activity index for acoustical bat data is presented. The AI acoustical activity index) was highly correlated to bat passes but proved to be a less biased index of activity. The method dispenses with the need to define, identify and count bat passes and provides a simple means to quantify activity. This method uses the Anabat system where acoustic surveys are carried out in real time with the data saved directly to a computer hard drive, taking advantage of the date-time information encoded into each file. The method is based upon the presence absence of a species occurrence during one-minute time intervals and avoids inflating an index of activity that may reflect the behavior of the species sampled. Examples are given showing that the AI is an effective measure of bat activity allowing comparisons between sites, times and species.

}, keywords = {acoustic activity index, acoustic monitoring, AI, Anabat, bat pass, Chiroptera, echolocation, relative abundance, relative activity}, author = {Miller, Bruce W.} }