Acoustic characterization of the threatened bat Neoeptesicus innoxius (Chiroptera: Vespertilionidae) and two sympatric species in western Ecuador
DOI:
https://doi.org/10.15517/jm7kr371Keywords:
insectivorous bats; echolocation; Isla Santay; Ecuador; Molossidae; Vespertilionidae.Abstract
Introduction: Bioacoustics allows the study of the ecology and behavior of bats through the analysis of echolocation signals. In insectivorous bats, foraging strategies, prey preference, and habitat use are closely related to the emission patterns of echolocation signals. Identifying significant bat habitats and improving conservation efforts can benefit from understanding these relationships. Objectives: To describe the echolocation signals of an endangered species Neoeptesicus innoxius, and other commonly detected species in the study area, Myotis nigricans and Molossus molossus, to contribute to the construction of a bat echolocation call reference library in Western Ecuador. Methods: Mist nets were used to capture bats, and reference recordings were subsequently obtained using the Anabat Swift ultrasonic detector. Echolocation pulse selection for each species was carried out using Kaleidoscope Pro 5.6.8 and BatSound 4.2.1, measuring the following spectral and temporal parameters of the echolocation signals in the search phase: initial, final, and maximum energy frequency, pulse duration, and interpulse interval. Results: N. innoxius presented the echolocation signals with the greatest variability of the spectral and temporal parameters, emitting pulses with high modulation speed (with one prominent FM component), and of low modulation speed (with one prominent QCF component); M. nigricans emissions were characterized by broadband signals of very short duration; and M. molossus presented alternation in its echolocation signals, where both high and low pulses had very little variability. Conclusions: The acoustic description of an endangered species like N. innoxius alongside the descriptions of other species frequently detected at the same study site, contributes to the construction of a bat echolocation call reference library. This input is the basis of future research of the ecology and behavior of the insectivorous bats that inhabit the Western Ecuador, which in turn is very valuable for designing tools and strategies for bat conservation.
References
Adams, A. M., Davis, K., & Smotherman, M. (2017). Suppression of emission rates improves sonar performance by flying bats. Scientific reports, 7(41641), 1–9. https://doi.org/10.1038/srep41641
Arias-Aguilar, A., Hintze, F., Aguiar, L. M., Rufray, V., Bernard, E., & Ramos, M. J. (2018). Who’s calling? Acoustic identification of Brazilian bats. Mammal Research, 63, 231–253. https://doi.org/10.1007/s13364-018-0367-z
Arévalo-Cortés, J., Tulcan-Flores, J., Zurc, D., Montenegro-Muñoz, S. A., Calderón-Leytón, J. J., & Fernández-Gómez, R. A. (2024). Description of the echolocation pulses of insectivorous bats with new records for Southwest Colombia. Mammal Research, 69, 231–244. https://doi.org/10.1007/s13364-023-00734-x
Barbosa, E. S., Figueiredo, D., de Melo, F. Â., da Costa-Pinto, A. L., Brito, A. C., Hintze, F., Vilar, E. M., Lopes, A. M., Ranulpho, R., Ferrari, S. F., & de Queiróz, D. (2022). Bats from Alagoas State, Northeastern Brazil: Updated checklist based on literature, collections and acoustic records. Mastozoología Neotropical, 29(2), e0613. https://doi.org/10.31687/saremMN.22.29.2.02.e0613
Barclay, R. M. R., & Brigham, R. M. (2004). Geographic variation in the echolocation calls of bats: A complication for identifying species by their calls. In R. M. Brigham, E. K. V. Kalko, G. Jones, S. Parsons, & H. J. G. A. Limpens (Eds.), Bat echolocation research: Tools, techniques and analysis (pp. 144). Bat Conservation International.
Barlow, K. (1999). Expedition field techniques: Bats (Serie Expedition Field Techniques). Expedition Advisory Centre, Royal Geographical Society.
Burneo, S., Proaño, M., & Tirira, D. (2015). Plan de acción para la conservación de los murciélagos del Ecuador. Programa para la Conservación de los Murciélagos del Ecuador y Ministerio del Ambiente del Ecuador. https://www.relcomlatinoamerica.net/images/PDFs/PlanAccionPCME.pdf
Carvalho, W. D., Miguel, J. D., & da Silva, X. B. (2023). Complementariedad entre redes de niebla y grabadores acústicos de bajo costo para muestrear murciélagos en las selvas y sabanas amazónicas. Ecología Comunitaria, 24, 47–60.
Cao, Z., Li, C., Wang, K., He, K., Wang, X., & Yu, W. (2023). A fast and accurate identification model for Rhinolophus bats based on fine-grained information. Scientific Reports, 13(1), 16375. https://doi.org/10.1038/s41598-023-42577-1
Centro Interdisciplinare di Bioacustica e Ricerche Ambientali. (2013). SeaWave – Sound Emission Analyzer Wave edition 2.0 [Software]. Università degli Studi di Pavia, Italy.
Cláudio, V. C., Novaes, R. L. M., Gardner, A. L., Nogueira, M. R., Wilson, D. E., Maldonado, J. E., Oliveira, J. A., & Moratelli, R. (2023). Taxonomic re-evaluation of New World Eptesicus and Histiotus (Chiroptera: Vespertilionidae), with the description of a new genus. Zoologia (Curitiba), 40, e22029. https://doi.org/10.1590/S1984-4689.v40.e22029
Cruz-Cordovez, C., Freire-Mayorga, E., Espinoza de Janon, F., Herrera-Gonzalez, I., Rizzo-Ochoa, K., & Ordoñez-Carpio, L. (2019). Plantas Terrestres Vasculares en la Ciclovía de Isla Santay. Universidad de Especialidades Espíritu Santo, Ecuador.
Estrada-Villegas, S., Rodríguez-Moreno, R., & Barboza-Marquez, K. (2018). Bioacústica: Ecolocación en murciélagos: fundamentos, usos y equipos. Red latinoamericana y del Caribe para la conservación de los murciélagos. https://relcomlatinoamerica.net/investigaci%C3%B3n/bioac%C3%BAstica.html
Fenton, M. B., Acharya, L., Audet, D., Hickey, M. B. C., Merriman, C., Obrist, M. K., Syme, D. M., & Adkins, B. (1992). Phyllostomid bats (Chiroptera: Phyllostomidae) as indicators of habitat disruption in the Neotropics. Biotropica, 24(3), 440–446. https://doi.org/10.2307/2388615
Frick, W. F. (2013). Acoustic monitoring of bats, considerations of options for long-term monitoring. Therya, 4(1), 69–70. https://doi.org/10.12933/therya-13-109
Görföl, T., Huang, J. C., Csorba, G., Győrössy, D., Estók, P., Kingston, T., Szabadi, K. L., McArthur, E., Senawi, J., Furey, N. M., Tu, V. T., Thong, V. D., Khan, F. A. A., Jinggong, E. R., Donnelly, M., Kumaran, J. V., Liu, J. N., Chen, S. F., Tuanmu, M. N., … Zsebők, S. (2022). ChiroVox: a public library of bat calls. PeerJ, 10, e12445. https://doi.org/10.7717/peerj.12445
Jacobs, D. S., Barclay, R. M. R., & Walker, M. H. (2007). The allometry of echolocation call frequencies of insectivorous bats: why do some species deviate from the pattern? Oecologia, 152, 583–594.
Jones, G. (1997). Acoustic signals and speciation: the roles of natural and sexual selection in the evolution of cryptic species. Advances in the Study of Behaviour, 26, 317–354.
Jones, G., & Holderied, M. W. (2007). Bat echolocation calls: adaptation and convergent evolution. Proceedings of the Royal Society B: Biological Sciences, 274(1612), 905–912. https://doi.org/10.1098/rspb.2006.0200
Jones, G., & Rayner, J. M. (1989). Foraging behavior and echolocation of wild horseshoe bats Rhinolophus ferrumequinum and R. hipposideros (Chiroptera, Rhinolophidae). Behavioral Ecology and Sociobiology, 25, 183–191. https://doi.org/10.1007/BF00302917
Jones, G., & Teeling, E. C. (2006). The evolution of echolocation in bats. Trends in Ecology and Evolution, 21(3), 149–156.
Jung, K., Molinari, J., & Kalko, E. K. (2014). Driving factors for the evolution of species-specific echolocation call design in New World free-tailed bats (Molossidae). PLOS One, 9, e85279. https://doi.org/10.1371/journal.pone.0085279
Kössl, M., Mora, E., Coro, F., & Vater, M. (1999). Two-toned echolocation calls from Molossus molossus in Cuba. Journal of Mammalogy, 80(3), 929–932. https://doi.org/10.2307/1383262
Kraker-Castañeda, C., Santos-Moreno, A., Lorenzo, C., & MacSwiney, M. C. (2018). Effect of intrinsic and extrinsic factors on the variability of echolocation pulses of Myotis nigricans (Schinz, 1821) (Chiroptera: Vespertilionidae). Bioacoustics, 28(4), 366–380. https://doi.org/10.1080/09524622.2018.1461685
Limpens, H. J. G. A. (2004). Field identification: Using bat detectors to identify species. In R. M. Brigham, E. Kalko, G. Jones, S. Parsons, & H. Limpens (Eds.), Bat echolocation research: Tools, techniques and analysis (pp. 46–57). Bat Conservation International.
Linares, O. J., & Zabala, E. (2018). Refugios diurnos de Eptesicus innoxius (Chiroptera, Vespertilionidae), en la Provincia de Guayas, Ecuador. Investigatio, (11), 29–40. https://revistas.uees.edu.ec/index.php/IRR/article/view/172.
López-Bosch, D., Huang, J. C. C., Wang, Y., Palmeirim, A. F., Gibson, L., & López-Baucells, A. (2021). Bat echolocation in continental China: a systematic review and first acoustic identification key for the country. Mammal Research, 66, 405–416. https://doi.org/10.1007/s13364-021-00570-x
Mancini, M. C. S., Bobrowiec, P. E. D., Oliveira, L. L., Del Sarto-Oliveira, L. L., & Gregorin, R. (2024). Better together: integrating mist-nets and bioacoustics reveals large-scale native vegetation as a key predictor of bat community conservation in a fragmented landscape. Biodiversity Conservation, 33, 1503–1521. https://doi.org/10.1007/s10531-024-02813-0
Martínez-Medina, D., Sánchez, J., Zurc, D., Sánchez, F., Otálora-Ardila, A., Restrepo-Giraldo, C., Acevedo-Charry, O., Hernández, F., & Lizcano, D. J. (2021). Estándares para registrar señales de ecolocalización y construir bibliotecas de referencia de murciélagos en Colombia. Biota Colombiana, 22(1), 36–56.
Mora, E. C., Macías, S., Rojas, D., Rodríguez, A., Quiñonez, I., García, A., Cádiz, A., & Boburg, B. (2002). Aplicación de métodos bio acústicos y convencionales en la caracterización de la comunidad de murciélagos de la Cueva del Indio, Tapaste, La Habana, Cuba. Revista Biología, 16(2), 159–166.
Mora, E. C., Macías, S., Vater, M., Coro, F., & Kössl, M. (2004). Specializations for aerial hawking in the echolocation system of Molossus molossus (Molossidae, Chiroptera). Journal of Comparative Physiology A, 190, 561–574. https://doi.org/10.1007/s00359-004-0519-2
Orozco-Lugo, L., Guillén-Servent, A., Valenzuela-Galván, D., & Arita, H. T. (2013). Descripción de los pulsos de ecolocalización de once especies de murciélagos insectívoros aéreos de una selva baja caducifolia en Morelos, México. Therya, 4(1), 33–46. https://doi.org/10.12933/therya-13-103
Paz-Ramírez, T., Au Hing Cujilán, A., & Salas, J. A. (2018). Notas sobre algunas Especies de Quirópteros en Tres Bosques Protectores Periurbanos de Guayaquil, con Comentarios sobre su Estado de Conservación. Investigatio, 11, 41–56. http://revistas.uees.edu.ec/index.php/IRR/article/view/164/168
Paz-Ramírez, T., & Salas, J. A. (2019). Evaluación de tres bosques protectores periurbanos del cantón Guayaquil (Guayas, Ecuador) como potenciales áreas de importancia para la conservación de murciélagos. Mammalia aequatorialis, 1, 31–41. https://doi.org/10.59763/mam.aeq.v1i.5
Pech-Canche, J. M., Estrella, E., López-Castillo, D. L., Hernández-Betancourt, S. F., & Moreno, C. E. (2011). Complementarity and efficiency of bat capture methods in a lowland tropical dry forest of Yucatán, Mexico. Revista Mexicana de Biodiversidad, 82(3), 896–903. http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1870-34532011000300016&lng=es&tlng=en
Pettersson Elektronik AB. (2013). BatSound (Versión 4.2.1) [Software]. Uppsala, Sweden.
R Core Team. (2024). R: A Language and Environment for Statistical Computing [Software]. R Foundation for Statistical Computing. https://www.R-project.org/
Redgwell, R. D., Szewczak, J. M., Jones, G., & Parsons, S. (2009). Classification of echolocation calls from 14 species of bat by support vector machines and ensembles of neural networks. Algorithms, 2(3), 907–924. https://doi.org/10.3390/a2030907
Rivera-Parra, P., & Burneo, S. (2013). Primera biblioteca de llamadas de ecolocalización de murciélagos del Ecuador. Therya, 4(1), 79–88. https://doi.org/10.12933/therya-13-104
Russo, D., & Voigt, C. C. (2016). The use of automated identification of bat echolocation calls in acoustic monitoring: A cautionary note for a sound analysis. Ecological Indicators, 66, 598–602. https://doi.org/10.1016/j.ecolind.2016.02.036
Rydell, J., Nyman, S., Eklöf, J., Jones, G., & Russo, D. (2017). Testing the performances of automated identification of bat echolocation calls: A request for prudence. Ecological Indicators, 78, 416–420. https://doi.org/10.1016/j.ecolind.2017.03.023
Salas, J. A., Burneo, S. F., Viteri, F., & Carvajal, R. (2014). First record of the pale-faced bat Phylloderma stenops Peters 1865 (Chiroptera: Phyllostomidae) in the province of Guayas, Southwest Ecuador. Check List, 10(5), 1218–1222. https://doi.org/10.15560/10.5.1218
Salas, J. A. (2019). Revisión del estado del conocimiento sobre los murciélagos neotropicales y el ecosistema de manglar: completando un vacío de la biodiversidad en los manglares del Ecuador. In N. Molina-Moreira & F. Galvis (Comp.), Manglares del Ecuador. Primer Congreso Manglares de América (pp. 69–79). Universidad Espíritu Santo, Samborondón-Ecuador.
Salas, J. A. (2022). Ecuador / A-EC-008: Isla Santay. In R. M. Barquez, L. F. Aguirre, J. M. Nassar, S. F. Burneo, C. A. Mancina, & M. M. Díaz (Eds.), Áreas y sitios de importancia para la conservación de los murciélagos en Latinoamérica y el Caribe (p. 290). RELCOM.
Salas, J. A., Loaiza, C. R., & Cadenillas, R. (2023). Eptesicus innoxius (Chiroptera: Vespertilionidae). Mammalian Species, 55(1033), 1–9. https://doi.org/10.1093/mspecies/sead008
Schnitzler, H. U., & Kalko, E. K. V. (2001). Echolocation by insect-eating bats: We define four distinct functional groups of bats and find differences in signal structure that correlate with the typical echolocation tasks faced by each group. BioScience, 51(7), 557–569. https://doi.org/10.1641/0006-3568(2001)051[0557:EBIEB]2.0.CO;2
Siemers, B. M., Kalko, E. K. V., & Schnitzler, H. U. (2001). Echolocation behavior and signal plasticity in the Neotropical bat Myotis nigricans (Schinz, 1821) (Vespertilionidae): A convergent case with European species of Pipistrellus? Behavioral Ecology and Sociobiology, 50, 317–328. https://doi.org/10.1007/s002650100379
Stahlschmidt, P., & Brühl, C. A. (2012). Bats as bioindicators – The need of a standardized method for acoustic bat activity surveys. Methods in Ecology and Evolution, 3(3), 503–508. https://doi.org/10.1111/j.2041-210X.2012.00188.x
Stidsholt, L., Johnson, M., Goerlitz, H. R., & Madsen, P. T. (2021). Wild bats briefly decouple sound production from wingbeats to increase sensory flow during prey captures. iScience, 24(8), 102896. https://doi.org/10.1016/j.isci.2021.102896
Stilz, W. P., & Schnitzler, H. U. (2012). Estimation of the acoustic range of bat echolocation for extended targets. The Journal of the Acoustical Society of America, 132(3), 1765–1775. https://doi.org/10.1121/1.4733537
Surlykke, A., & Kalko, E. K. V. (2008). Echolocating bats cry out loud to detect their prey. PLoS ONE, 3(4), e2036. https://doi.org/10.1371/journal.pone.0002036
Tinajero, J. (2017). Composición de los ensambles de comunidades de murciélagos del Bosque Protector Cerro Blanco, Guayaquil [Trabajo de titulación de licenciatura, Pontificia Universidad Católica del Ecuador]. Quito, Ecuador.
Tirira, D. G. (2017). Guía de campo de los mamíferos del Ecuador (2ª ed.). Asociación Ecuatoriana de Mastozoología y Editorial Murciélago Blanco.
Torres-Domínguez, A., Salas, J. A., & Hurtado, C. M. (2022). Medium and large-sized mammals from Isla Santay National Recreation Area in western Ecuador. Revista Peruana de Biología, 29(1), e21497. https://doi.org/10.15381/rpb.v29i1.21497
Velazco, P., & Aguirre, L. (2020). Eptesicus innoxius (amended version of 2016 assessment). The IUCN Red List of Threatened Species. https://www.iucnredlist.org/species/7932/166506353
Wildlife Acoustics Inc. (2024). Kaleidoscope Pro (version 5.6.8) [Software]. Maynard, Massachusetts, United States.
Yoh, N., Kingston, T., McArthur, E., Aylen, O. E., Huang, J., Jinggong, E. R., Khan, F., Lee, B., Mitchell, S. L., Bicknell, J. E., & Struebig, M. J. (2022). A machine learning framework to classify Southeast Asian echolocating bats. Ecological Indicators, 136, 108696. https://doi.org/10.1016/j.ecolind.2022.108696
Zamora‐Gutierrez, V., Lopez‐Gonzalez, C., MacSwiney Gonzalez, M. C., Fenton, B., Jones, G., Kalko, E. K. V., Puechmaille, S. J., Stathopoulos, V., & Jones, K. E. (2016). Acoustic identification of Mexican bats based on taxonomic and ecological constraints on call design. Methods in Ecology and Evolution, 7(9), 1082–1091. https://doi.org/10.1111/2041-210X.12556
Zamora-Gutierrez, V., Ortega, J., Avila-Flores, R., Aguilar-Rodríguez, P. A., Alarcón-Montano, M., Avila-Torresagatón, L. G., Ayala-Berdón, J., Bolívar-Cimé, B., Briones-Salas, M., Chan-Noh, M., Chávez-Cauich, M., Chávez, C., Cortés-Calva, P., Cruzado, J., Cuevas, J. C., Del Real-Monroy, M., Elizalde-Arellano, C., García-Luis, M., García-Morales, R., … McSwiney, M. C. (2020). The Sonozotz project: Assembling an echolocation call library for bats in a megadiverse country. Ecology and Evolution, 10(11), 4928–4943. https://doi.org/10.1002/ece3.6245
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