Nyctinomops aurispinosus is one of four species of the genus Nyctinomops (Molossidae) and is considered monotypic. This insectivorous species has a wide but poorly known neotropical distribution. This study documents the first record of the species for the Sama Valley, Tacna department, Perú. In addition, a current distribution map of the species is presented together with facts concerning its dietary composition. The specimen was collected using mist nets during a local bat study and compared with N. aurispinosus individuals in the scientific collection of the Museo de Historia Natural Javier Prado, Universidad Nacional Mayor de San Marcos. The distribution map was made of published records and the diet of the specimen was analyzed by stereoscopy of the contents of its digestive tract. The collected specimen was identified as an adult male N. aurispinosus in reproductive condition. Analysis of the digestive tract contents showed that its diet was composed of lepidopterans. The current distribution map of the species consisted of a total of 78 published records. This new record for Tacna department expands the distribution of N. aurispinosus ca. 270 km to the south of Camaná, Arequipa department, becoming the southernmost record for the Pacific coast. The lepidopteran remains in the digestive tract show that its diet is similar to those reported for other molossids. This finding extends the known distribution of this species to the southwest of South America and increases to ten the number of bat species known from Tacna department. The proximity of this Peruvian record to Chilean territory and regional habitat continuity suggests the probable presence of N. aurispinosus in that country.

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...

The recently described bat Lasiurus arequipae Málaga, Díaz, Arias & Medina, 2020 is endemic to Peru. Lasiurus are­quipae is currently known to occur at two localities in the department of Arequipa and one locality in the department of Tacna in southwestern Peru. Here, based on morphological and molecular data, we present a fourth locality that represents the southernmost record of this species and extends its known range 62 km south from the nearest locality in Tacna. Additionally, we provide information some aspects on the natural history and acoustic profile of L. arequipae.