Contributions to the natural history of Mormopterus kalinowskii (Chiroptera: Molossidae) in the southwest of Peru

Abstract

Mormopterus kalinowskii, is an insectivorous species restricted to the Andean western slopes of Peru and Chile, it is rare and has very scarce available information. We evaluated sex ratio, roost use, and relationship between reproductive patterns and monthly seasonal variation throughout a 13-month period. In addition, we performed the first description and characterization of its echolocation calls. The study area was located in the Ite Valley, Tacna department (southwestern Peru) at the northernmost part of the Atacama Desert, one of the driest deserts in the world. Bats were caught using mist-nets. Sex ratio in the population was calculated from all individuals captured, and its difference with regard to a 1:1 ratio was assessed through a Binomial Coefficient Test. Roost use was assessed through observation and inspection of the study area. Pearson and Spearman correlation coefficients were calculated to establish the relationship between the number of captures and temperature and precipitation data. Echolocation calls were recorded using a Petterson D240x Ultrasound detector plugged to a digital recorder. Spectrogram displays of recorded calls allowed describing structural patterns within echolocation calls and to measure frequency and time parameters. 79 individuals of M. kalinowskii were captured; 30 males and 49 females. Sex ratio obtained, 1:1.63, evidenced more females in the study area. M. kalinowskii uses crevices as roosts and has a single reproductive cycle per year. Higher capture rates are correlated with temperature (r = 0.526), but not precipitation (r = 0.096). Calls in search phase exhibited long duration pulses and a descending quasi-constant frequency (QCF) component from 39 to 33 kHz, reducing length and increasing bandwidth when attempting to catch prey. The sex ratio, 1:1.63 (≈ 2), suggests that M. kalinowskii is a polygamous species, as occurs in the others molossids, whereas the single annual reproductive cycle shown by M. kalinowskii would indicate a seasonal monoestrous reproductive pattern. Echolocation calls share several traits observed in other molossids; however, the frequency values for M. kalinowskii search phase pulses could be the highest recorded among the molossid bats of the Pacific coastal desert, allowing them to detect smaller prey as a strategy to mitigate food competition among insectivorous bats in arid environments. Mormopterus kalinowskii, es una especie insectívora restringida a la vertiente occidental de Perú y Chile, monotípica y rara con muy escasa información disponible. Evaluamos la proporción de sexos, uso de refugios y la relación entre el patrón reproductivo de la especie y las épocas de calor y precipitación durante 13 meses en una población de M. kalinowskii en el Valle de Ite, departamento de Tacna (al suroeste del Perú), al comienzo del desierto de Atacama, uno de los más secos del mundo. Además, realizamos la primera descripción y caracterización de las llamadas de ecolocalización de la especie. Los murciélagos fueron capturados usando redes de niebla...

New record of Nyctinomops aurispinosus with an update of its known distribution

“…The roosts that N. aurispinosus probably uses in the Sama valley are rock cracks in steep slopes, as has been observed for Mormopterus kalinowskii, Promops davisoni, and Tadarida brasiliensis in nearby valleys (Aragón and Aguirre 2014;Flores-Quispe et al 2019). Previous reports referred to its occupation of cracks and caves with other molossids (Ortiz de la Puente 1951;Sanborn 1951;Carter and Davis 1961;Álvarez 1963), as well as high-rise human constructions (Taddei and Garutti 1981;Ochoa 1984;Bianconi et al 2009).…”

Uso de hábitat de los murciélagos insectívoros en un bosque artificial de La Molina y alrededores (Lima, Perú)

“…El análisis de las grabaciones se realizó con el programa BatExplorer (Elekon AG, Versión 2.1, http://www.batlogger.com) obteniendo de cada llamada en fase de búsqueda 8 parámetros acústicos: frecuencia inicial (FI), frecuencia final (FF), duración del pulso (D), intervalo entre pulsos (IP, en ms), frecuencia de máxima amplitud (FMA), ancho de banda (BW), número de armónicos y los datos de componentes (Comp) que pueden ser frecuencia modulada (FM), frecuencia cuasi-constante (FQC) y frecuencia constante (FC) (Fraser et al 2020). Las especies registradas se identificaron comparando los sonogramas con la biblioteca bioacústica del Centro de Investigación Biodiversidad Sostenible y con otros estudios referentes a la bioacústica en murciélagos insectívoros presentes en Lima (Guillam & McCracken 2007, Falcão et al 2015, Pacheco et al 2015, Arias-Aguilar et al 2018, Ossa et al 2018, Flores-Quispe et al 2019, Pacheco et al 2020, Ugarte et al 2020. A cada especie, se le asignó el gremio trófico según Gannon et al (2003): recolector, con señales de frecuencia mínima mayor a 30 kHz, multiarmónicos y de duración corta entre 1 a 3 ms; cazador aéreo, con señales de búsqueda de banda estrecha con larga duración entre 8 a 25 ms, frecuencia menor a 30 kHz; o estratega mixto, con señales de duración entre 3 a 10 ms, frecuencia media entre 30 a 60 kHz.…”