Northern distributional extensions of Peropteryx leucoptera and Peropteryx pallidoptera (Chiroptera: Emballonuridae) from Vichada, Colombia

The White-winged Dog-like Bat ( Peropteryx leucoptera ) and the Pale-winged Dog-like Bat ( Peropteryx pallidoptera ) are distinguished from the other emballonurid bats because they have white or translucent wings. Their distribution and biology are poorly known due to they are not usyally captured in traditional bat inventories using mist nets. In this contribution, we extend the known distribution of P . leucoptera 260 km NE and P . pallidoptera 290 km NE. Our records are from three specimens collected in a mammal assessment at the riparian corridor of the river Meta in the Vichada department. This locality is the northern limit of the distributional range of both species. We highlight the need to continue the fieldwork on mammals inventories with specimen collections through the Colombian Llanos. We call attention to the importance of horizontal rotten logs as roost of P . leucoptera and other little known neotropical bats.

The Dog-like bats of the genus Peropteryx Peters, 1867 are widely distributed in the lowlands of the Neotropics. The genus contains five recognized species (Bonaccorso 2019): P. macrotis (Wagner 1843); P. kappleri Peters, 1867;P. trinitatis Miller, 1899;P. leucoptera Peters, 1867 andP. pallidoptera Lim, Engstrom, Reid, Simmons, Voss, &Fleck, 2010. These bats are small to medium-sized emballonurids (forearm 38-54 mm) and differ from other species of the family Emballonuridae because they have a small wing sac located in the leading edge of the antebrachial membrane, the skull has an expanded rostrum an undivided basisphenoid pit without a medial septum, and a spicule-like anterior upper premolar (Hood & Gardner 2008).
Among Peropteryx species, P. leucoptera and P. pallidoptera are distinguishable because they have translucent or white wings. These species were previously confused among them, and their distribution and biology are poorly known due to they are no commonly captured in traditional bat inventories using mist nets McDonough et al. 2010). The current distribution of P. leucoptera comprises French Guiana, Guyana, Suriname, Venezuela, Colombia, Peru, Brazil, and Ecuador, where it inhabits tropical rainforest and riparian forest in savannas (Suarez-Castro et al. 2012;Mikalauskas et al. 2014). In Colombia, P. leucoptera has been reported from a riparian forest of savanna ecosystems in the Colombian Llanos and lowland tropical rainforest of La Macarena mountains, in the departments of Meta and Casanare (Suárez-Castro et al. 2012;Mantilla-Meluk et al. 2014). On the other hand, P. pallidotera is known from Ecuador, Peru, Brazil, and Colombia, where inhabits the Amazonian tropical rainforests and riparian forest in savanna ecosystems in the Colombian Llanos McDonough et al. 2010;Suárez-Castro et al. 2012;Morales-Martínez 2013). In Colombia, P. pallidoptera is known from the east versant of the Andes in the Caquetá department in a transitional forest between the Amazon and Andean regions, and from riparian forests of the Colombian Llanos in the Meta department During a mammal's rapid assessment in the floodplain forest of the Meta river in the Vichada department, we recorded three bats identified as P. leucoptera and P. pallidopera. Here, we report these records that significantly extend the range of distribution of both species.
The mammal's rapid assessment was conducted in June 2017 during the rainy season at La Bendición Farm (6°04'7,3''N, 69°10'30,4''W WGS84 Elevation 90 -110 m.a.s.l.), located in the north of the Vichada department ( Figure 1). This locality is in the Llanos ecoregion, in the Tropical and subtropical grasslands, savannas, and shrublands Biome (Dinerstein et al. 2017), and the flat high plain savannas ecosystem (Romero-Ruiz et al. 2010). The area comprises the riparian corridor of the Meta River. Sampled habitats comprise: 1. Meta river´s floodplain forest, 2. gallery forest of streams that empty into the Meta river, and 3. open savannas with spread shrubs. The weather is mega-thermal and wet, the mean temperature varies between 27 and 28 °C. Seasonality of precipitation is monomodal with two seasons, the dry season is between December and March and the wet between April and November, with annual precipitation between 2.000 and 2.500 mm, and the wettest month is June (Minorta-Cely & Rangel-Ch 2014). Bats were caught using mist nets at ground level. The nets were opened before sunset and closed after midnight (17h00 -00h00). We had a sampling effort per night of 288 meters per night per hour (m.n.h) and a total sampling effort of 1.152 m.n.h. All captured bats were handled based on the animal care and guidelines of the American Society of Mammalogists (Sikes et al. 2016). We checked captured bats for identification, sex, and reproductive status. We preserved almost one voucher specimen per species, fixed in 10 % formalin, and preserved in 90 % ethanol to confirm the identification and build a reference collection. Collected bats were euthanized using the thoracic compression procedure (Sikes et al. 2016). We took tissue samples and preserved these in 96 % ethanol. We extracted and cleaned the specimen's skulls using dermestids. The specimens were processed and deposited in the collection of Mammals "Alberto Cadena García" of Instituto de Ciencias Naturales, Universidad Nacional de Colombia (ICN). Specimens were collected under a research license as per Resolution No 500.41-16-0884 dated July 19th, 2016 granted by CORPORINOQUIA.
We based the P. leucoptera records on two females (ICN 24290, 24291). ICN 24290 is a juvenile with no completely ossified phalanx and translucent dactylopatagium, and the ICN 24291 was lactating. Our specimens coincide in all characteristics with previous descriptions of P. leucoptera (Hood & Gardner 2008;Lim et al. 2010;Suarez-Castro et al. 2012): Wings white beyond of forearm and attached to the inferior extremities at the metatarsals. Ears joined above the forehead with a band of skin. The skull has a basisphenoid pit deep, with two large and deep lateral pterygoid pits (Figure 2a -2c). Skull measurements are in the known range (Table 1). We captured these specimens in a net installed next to a horizontal rotten log (length= 3 m x high = 1,5 m), near a creek in the floodplain forest. We observed three additional bats, apparently of the same species, at the interior of the same horizontal rotten log but we were unable to catch them.
We based the P. pallidoptera record on one female (ICN 24292). Our specimen coincides in all characteristics with previous descriptions of P. pallidotera ): Ears separated. Translucent wings (plagiopatagium, dactylopatagium, and propatagium) attached to the inferior extremities at the ankle. The skull has the lateral pterygoid pits small and separated by a mesopterygoid extension between them (Figure 2d -2f ). The skull measurements are in the known range. (Table 1). This specimen was capture using mist-nets at one side of a stream in the gallery forest. Our records extend the known distribution ranges of P. pallidoptera 290 km NE (Morales-Martínez 2013) and P. leucoptera 260 km NE (Suárez-Castro et al. 2012), comprising the current northern limit of the distributional range of both species (Bonaccorso 2019). Additionally, these records are the first reports of both species for the Vichada department (Solari et al. 2013;Mosquera-Guerra et al. 2017). Our records suggest that these species could be distributed along riparian forests in the Orinoco Llanos as Mantilla-Meluk et al. (2014)  The knowledge about mammals in the Orinoco Llanos is low due to the sampling is small and disperse geographically and temporally with spread inventories in specific localities (Ferrer-Pérez et al. 2009;Trujillo et al. 2010). Even though the Llanos region has continuous oil exploitation, there are plenty of environmental impact studies with information about mammals, unfortunately, this information is hard to access, and their quality is uncertain (Trujillo et al. 2010;Gómez-Sandoval et al. 2017). Then, we highlight the urgent need to increase the study and to inventory biodiversity along this extensive natural region, which comprises 30,4 % of the Colombian territory.