First confirmed records of the rare Short-eared Bat , Cyttarops alecto Thomas , 1913 ( Chiroptera : Emballonuridae ) , from the Orinoco Llanos of Colombia

We confirm the occurrence of the rare bat Cyttarops alecto in piedmont and alluvial plain savannas of the Orinoco Llanos. Our records are the first for the species in Colombia in 22 years. The species was known only from Neotropical rainforests and one locality in the Cerrado formation in Brazil. Our records are supported with voucher specimens that match the diagnosis and variability described for the species. With these records, we reduce the geographical distribution gap between known Trans-Andean and Cis-Andean localities of this species in the northern Neotropics.

In Colombia, C. alecto was known from only one specimen that was captured in 1972 in Leticia, department of Amazonas (Ochoa et al. 1994;Solari et al. 2013).Later, Cuervo et al. (1986) reported the species from the lowlands of Colombia, and Alberico et al. (2000) reported it from the department of Vichada.The latter record is based on material deposited at Instituto de Investigación de Recursos Biológicos Alexander von Humboldt, Villa de Leyva (IAvH).However, neither Cuervo et al. (1986) nor Alberico et al. (2000) provided catalogue numbers of vouchers or specific localities to confirm this species' distribution.The hypothesis is that the distribution of C. alecto in Colombia comprises the Amazonian region south of the Putumayo River, and that the presence of the species in the Caribbean and Orinoco regions is still uncertain (Mantilla-Meluk et al. 2014).
Herein, we present the first confirmed records of C. alecto from the Orinoco Llanos of Colombia.Our records come from two different natural regions following Sarmiento (1983): the piedmont savannas and the alluvial plains.We also looked for specimens in the mammal collection of IAvH that would support the previous report of this species by Alberico et al. (2000).We comment the morphological variation of the species based on our material and that previously described in the literature.Additionally, we provide insights on the habitats of the species.
We consulted specimens housed in the mammalian collection "Alberto Cadena García" of Instituto de Ciencias Naturales of the Universidad Nacional de Colombia (ICN), and the collection of mammals of IAvH.External measurements were transcribed from specimen tags.Forearm and skull measurements were taken following Simmons and Voss (1998) with digital calipers to the nearest 0.01 mm.15-14-172-010CE with the Instituto de Investigación de Recursos Biológicos Alexander von Humboldt.These records were found in alluvial flood plains that occupy a vast depression in the central llanos where the hyperseasonal savanna ecosystem is most widespread.This savanna is mainly treeless and dominated by grasses and riparian forest patches that are flooded during the rainy period (Sarmiento 1983).
We found only one specimen identified as C. alecto (IAvH 1323, from Vichada department, Colombia) in the collection of mammals of the IAvH; however, this specimen corresponds to Myotis nigricans Schinz, 1821.Therefore, we consider uncertain the distribution of C. alecto in Vichada department.
Our record from piedmont savannas corresponds to an adult female (ICN 21656) found in the uncatalogued specimens of the collection of mammals of ICN.The specimen was collected by Alberto Cadena in 1982 in Hacienda el Hachón near Villavicencio city (Figure 1. Table 1).The locality is characterized by alluvial fans, and terraces dominated by savannas with semideciduous forest corridors along the rivers and creeks.We collected additional records (ICN 21910, 21911, 21912) and IAvH (Temp-ABJ690; RCFR 392) in alluvial plains in 2015 using ground mist nets in territories of the department of Casanare (Figure 1; Table 1).Captures were made under the research permit 500-41-15.07209 of CORPORINOQUIA and by the agreement  (Ochoa et al. 1994) Cyttarops alecto is an aerial insectivore emballonourid, characterized by its moderate size (forearm 40-47 mm), smoky gray pelage, and the lack of wing sacs or glands in the uropatagium.The skull exhibits a deep cuplike depression in the rostrum and the postorbital processes are long and not fused to the supraorbital ridge (Hood and Gardner 2008).All specimens have the external and cranial diagnosed characters mentioned above (Figures 2 and 3; Jones and Hood 1993;Hood and Gardner 2008).However, our specimens show variation in some recently reported characters, such as a diastema between the upper premolars, a naked patch of skin over the front head, and a posterior ventral process of the mandible (Velazco et al. 2011;Tavares et al. 2012).In our material, the diastema between the upper premolars remains, but do not have a naked patch of skin over the front head.The posterior ventral process of the mandible presents intraspecific variation from completely absent to highly developed, including specimens from the same locality and the same sex (ICN 21912 and IAvH-Temp-ABJ690 [RCFR 392]).
Measurements of our records concur with earlier reports from Brazil (Thomas 1913;Nunes et al. 2006;Tavares et al. 2012), Peru (Velazco et al. 2011), French Guiana (Masson and Cosson 1992), Nicaragua (Baker and Jones 1975), Costa Rica (Starrett and de la Torre 1964; Starrett and Casebeer 1968;Reid and Langtimm 1993), and Colombia (Ochoa et al. 1994) and show no evidence of notable variation throughout the species range (Table 2).Therefore, the external and craneo-dental measurements suggest that despite the lack of material available the morphological dissimilarities (see above) do not necessary represent geographic variations or different taxonomic entities as suggested by Velazco et al. (2011).
Our records are the first known from savanna ecosystems in northern South America.All previous localities for the species were in Amazonian and Guiana rainforests, Trans-Andean rainforests of Central America, and the Brazilian Cerrado (Thomas 1913 Baker and Jones 1975;Masson and Cosson 1992;Reid and Langtimm 1993;Ochoa et al. 1994;Nunes et al. 2006;Velazco et al. 2011;Rivas Rodríguez and Ferrer Pérez 2012;Tavares et al. 2012).Although the floristic composition is different between Brazilian Cerrado and Orinoco Llanos of Colombia, landscape similarities are evident showing savanna influence (Sarmiento 1983).
The occurrence of the species in other natural regions of South America, such as the Orinoco Llanos, means that these can provide additional roosts and suitable habitats for the species to inhabit, suggesting the ability of C. alecto to adapt to different environments (Starrett 1972;Velazco et al. 2011;Tavares et al. 2012).
The current distribution of this species in the Orinoco Llanos suggests that it may occur elsewhere in the region including the portion of the Llanos and Amazon in Venezuela.The new records documented here for the northern Neotropics reduce the distribution gap between the Cis-Andean and Trans-Andean regions and suggests the presence of the species in other lowlands of Colombia.
Although it has been suggested that ground mist nets are not appropriate to survey this type of bats (Velazco et al. 2011), all the specimens from Casanare were captured using this technique at ground level in clearings and along roads inside forests that are characterized by an abundance of palms as reported by Ochoa et al. (1994).However, the scarcity of material of C. alecto implies that bat sampling methods must include different approaches, such as canopy and subcanopy mist nests in addition to echolocation call recordings, as a way of maximizing the data collection.

ACKNOWLEDGEMENTS
We give special thanks to Hugo López Arevalo (ICN), Catalina Cárdenas González (ICN), and Claudia Medina (IAvH) for permitting us to study specimens under their care.We also sincerely thank our field assistants and the farm proprietors.Laboratorio de Equipos Ópticos Compartidos (LEOC) from the Departamento de Biología of Facultad de Ciencias, Universidad Nacional de Colombia provided photographic assistance of Figure 3.The specimens collected from the municipality of Hato Corozal, Casanare, were obtained during the project: "Conservación de especies amenazadas en el área de influencia del Oleducto Bicentenario, Convenio de cooperación No. 15-14-172-010CE between the Instituto de Investigación de Recursos Biológicos Alexander von Humboldt and the Fundación Reserva Natural La Palmita, Centro de Investigación".The specimens collected from municipality of Trinidad, Casanare, were obtained during the project "Programa de diagnóstico y monitoreo de la diversidad biológica de las sabanas inundables para la evaluación de su integridad ecológica.Primera etapa: Mamíferos y aves, orden de servicio OS 411000797 between Parex Resources Ltda., and the Fundación Reserva Natural La Palmita, Centro de Investigación."Héctor Ramírez Chaves and Camilo A. Calderón-Acevedo reviewed an early version of the manuscript.Two anonymous reviewers provided comments to the final version.

Figure 3 .
Figure 3. Dorsal (upper), ventral (middle) and lateral (lower) views of the skull and lateral view of the mandible of Cyttarops alecto (ICN 21656).Middle arrows: diastema between the upper premolars; bottom arrow: posterior ventral process of the mandible.
Calderón-Capote et al. | First confirmed records of Cyttarops alecto in Colombian Llanos