(2012). Records of the Phyllostomine Bats Tonatia Bidens
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Chiroptera Neotropical 18(2): 1139-1143, December 2012 Records of the Phyllostomine bats Tonatia bidens (Spix, 1823) and Lophostoma silvicolum d´Orbigny, 1836 (Chiroptera, Phyllostomidae) associated with human dwellings in Paraguay Smith Paul1,2,*, Pheasey Helen2, Atkinson Karina2, Miller Jonny2 1 Fauna Paraguay, Carmen de Lara Castro 422, Barrio San Roque, Encarnación, Paraguay 2 Para La Tierra, Reserva Natural Laguna Blanca, Municipio Santa Barbara, San Pedro, Paraguay * Corresponding author: [email protected] SHORT COMMUNICATION Abstract Manuscript history: Noteworthy records of two species of Phyllostomine bats using Submmited in 03/Sep/2012 human dwellings in Paraguay are presented. The use of unoccupied Accept in 31/Dec/2012 buildings by Tonatia bidens provides the first Paraguayan roosting Available on line in xx/Jan/2013 data for this species. Roosts of this species are persistent and Section editor: Ludmilla M.S. Aguiar contained 1 to 5 individuals. An unusual record of use of a building by the harem-breeding Lophostoma silvicolum is also reported. The species roosts in arboreal termitaria and its temporary use of buildings is attributed to transient, non-harem individuals in areas where natural refuges are in short supply. Keywords: roosts, Chaco, Cerrado, bachelor group Introduction L. silvicolum is a widespread Phyllostomine occurring as four subspecies from Honduras to Twenty-one species of Phyllostomidae Paraguay. It is absent from much of northern (American Leaf-nosed Bats) occur in Paraguay, Venezuela and the Andes, but occurs on the separated into five subfamilies (FAUNA Paraguay western Andean slope as far south as northwestern 2012). The Phyllostominae are represented by Peru and the eastern slope south to Bolivia. The seven species in five genera, each possessing a nominate subspecies L. s. silvicolum occurs in well-defined nose leaf, a W-shaped molar cusp Paraguay (Gardner 2007). López-González (2005) pattern and a well-developed interfemoral mentions just 8 specimens from Paraguay all from membrane (Gardner 2007). Very little is known of the northern Oriental region. the biology of the Phyllostominae in Paraguay and most species are rarely recorded in the country. In The roosting and breeding behaviour of L. this paper we provide information on noteworthy silvicolum has been fairly well studied, with males records of two little-known Phyllostomine bats, forming harems and excavating a nest within Tonatia bidens and Lophostoma silvicolum, using arboreal termitaria (Handley 1976, Kalko et al. human dwellings. 1999, Aguirre et al. 2003). Though Tuttle (1970) mentions that a local man claimed to have T. bidens is a fairly small Phyllostomine bat captured specimens roosting inside a hollow tree locally distributed from northeast Brazil east of in Peru, this information was not verifiable by the the Amazon south to eastern Bolivia, Paraguay author and would seem to be atypical. Esbérard & and northern Argentina (Barquez et al. 1993, dos Bergallo (2004) provided data on roost site Reis et al. 2007, Paca et al 2012). Though the selection for specimens of Tonatia bidens from species is a habitat generalist, almost everything Rio de Janeiro, Brazil, but the majority of older that is known about its biology was documented published references to the species in fact refer to by Martuscelli (1995) and Esbérard & Bergallo what is now known as Tonatia saurophila (2004) in Brazil and it apparently occurs at low Koopman & Williams, 1951 (Williams et al. density throughout its range. Myers et al. (1983) 1995). L. silvicolum has not previously been captured specimens in Paraguay over an isolated documented as using human dwellings. pond in thorn (Chaco) scrub (departamento Boquerón) and over a stream flowing through high Results tropical (Atlantic) forest (departamento Itapúa), T. bidens - Three male specimens of this but records from Paraguay are few (López- species (TK 114879, 114880, 114886) were González 2005). captured roosting inside an abandoned building at Estancia San Luís de la Sierra, departamento 1139 Chiroptera Neotropical 18(2): 1139-1143, December 2012 Concepción (S 22˚23'53'' W 57˚28'57'') on 15-16 the evening of collection shows a temperature November 1999 (R.Owen unpubl. data). These range of 23.63-25.17ºC and absolute humidity specimens are currently in the registered collection varying between 21.3 and 23.2 g/m3 (Para La of Dr Robert Owen in Asunción, but will Tierra unpublished data). The bat was already eventually be deposited in the Museo Nacional de present inside the house and the collector was Historia Natural del Paraguay, San Lorenzo, alerted to it when it took flight. Four nights later Paraguay (MNHNP). All specimens were on 29 January 2012 a male specimen CZPLT 213 collected as skull and post-cranial skeletons, and was collected in another building at the same specimens TK 114880 and TK 114886 were also location (S 23˚48'48'' W 56˚17'41''). Weather data prepared as skins. The external and cranial for the evening of collection shows a temperature measurements for these specimens are provided in range of 25.95-31.52ºC and absolute humidity Table 1. varying between 16.3 and 19.3 g/m3 (Para La On 15 April 2011 a single individual of this Tierra unpublished data). species was found roosting by day in a wardrobe Both specimens were prepared as a skin, skull in an unused, but not abandoned building at the and tissue, and ectoparasites (batflies) of specimen Parque Nacional Defensores del Chaco CZPLT 212 were also collected. The external and headquarters at Madrejón, departamento Alto cranial measurements for these specimens are Paraguay (S 20˚37'49'' W 59˚52'51''). The unsexed provided in Table 1. Images of specimen CZPLT specimen had only one pair of lower incisors (a 212 are available in Smith (2008) (image codes characteristic shared in Paraguay only with FPMAM1073-1074PH). Phyllostomid bats of the genera Chrotopterus and Discussion Lophostoma) and was identified as T. bidens on the basis of morphological characteristics (size, Esbérard & Bergallo (2004) listed roosts of T. furred muzzle, rounded tragus, well-separated ears bidens in caves, palm trees and mines in Rio de etc.). The record extends the known distributional Janeiro State, Brazil and Martuscelli (1995) range of T. bidens in Paraguay very slightly to the mentioned the use of abandoned buildings as north and is the first report of the species from feeding shelters for this species in São Paulo State. departamento Alto Paraguay. A voucher specimen The closely-related, but more northerly-distributed could not be collected due to permit restrictions, T. saurophila is known to roost in caves, hollow but images of the specimen are available in Smith trees and ruins (La Val & Rodriguez 2002, Siles et (2009) (image codes FPMAM949-952PH). Head al. 2003) suggesting some degree of similarity in park guard Silvino González (pers. comm.) roost site selection between the two species. Our commented that the bats had been there for some observations are consistent with the existing data time but that the number of bats present varied. and represent the first roosting data for T. bidens in Paraguay. On a second visit a few months later on 16 July 2011, five bats of the same species were L. silvicolum roost almost exclusively inside found to be present in the same room, though this active arboreal termitaria and operate a harem time roosting in a dark corner of an attached breeding system (Dechmann et al. 2007, 2009). bathroom. Photographs were taken of the group The implication of this breeding system and the which, once disturbed by the torchlight and comparative rarity of active arboreal termitaria camera flashes then departed through an open acting as a limiting factor, is the presence of non- skylight in the roof. An image of four members of harem, bachelor bats in any given population the group is also available in Smith (2009) (image (Dechmann & Kerth 2008). code FPMAM996H). A group of bats of this The two Laguna Blanca specimens were of species was also observed to be present in the differing sex and though their skulls indicated they same spot the following year on 5 and 6 July were fully adult, neither showed any signs of 2012. These observations suggest some degree of reproductive activity. Thus they were not fidelity in the use of the roost site by this species dispersing juveniles, and may have been members and it is of note that even within the unlit room the of bachelor groups. In the ecologically similar bats sought out the darkest areas available for Phyllostomus hastatus pre-reproductive females roosting. are often present in bachelor groups at a ratio of L. silvicolum - A female specimen CZPLT approximately 1:7 males, indicating that females 212 (Colección Zoológica de Para La Tierra. may temporarily reside in such groups prior to Laguna Blanca, San Pedro, Paraguay) was joining harems (McCracken & Bradbury 1981). collected inside the occupied accommodation Additional circumstantial evidence is building by fieldworkers at Para La Tierra consistent with these individuals being non-harem Biological Station, Reserva Natural Laguna individuals. Dechmann et al. (2005) noted that Blanca, departamento San Pedro (S 23˚48'43'' W males captured with a harem of females were in 56˚17'41'') on 25 January 2012. Weather data for notably better condition than those without 1140 Chiroptera Neotropical 18(2): 1139-1143, December 2012 females, being larger and heavier, though they by transient, non-harem individuals in areas where were unable to confirm whether the observed natural refuges are in short supply. differences were a product of condition related to Acknowledgements harem membership as opposed to age. Though the sample size is small it is perhaps significant that Special thanks to Dr Robert Owen for giving the forearm length of both of these specimens is us access to his unpublished field notes on a towards the upper end of the range provided by Tonatia bidens roost.