Journal of Mammalogy, 94(3):628–631, 2013 First report of a hard fruit in the diet of Centurio senex (Chiroptera: Phyllostomidae) in Mexico SERGIO M. MADRID-L ÓPEZ, ALEJANDRO A. CASTRO-LUNA, AND JORGE GALINDO-GONZÁLEZ* Instituto de Biotecnologı́a y Ecologı́a Aplicada (INBIOTECA), Universidad Veracruzana, Avenida de las Culturas Veracruzanas #101, Colonia Emiliano Zapata, Xalapa, Veracruz, CP 91090, México * Correspondent: jorgegalin@gmail.com; jgalindo@uv.mx Key words: bat frugivorous bat, fruit hardness, seed dispersal, Sideroxylon capiri, subdeciduous forest, Veracruz, wrinkle-faced Ó 2013 American Society of Mammalogists DOI: 10.1644/12-MAMM-A-218.1 The wrinkle-faced bat, Centurio senex (Phyllostomidae: Stenodermatinae), is a medium-sized bat (total length: 55–70 mm, forearm body mass: 41–45 mm, 17–28 g), characterized by a broad, flat face that has numerous hairless skin folds, and a jaw that juts forward. There is no true nose leaf, and there are glands in the neck that probably secrete an odoriferous substance (Nowak 1994). When roosting, males of this species cover their face with a chin fold that extends from the neck over the ears and over the top of the head (Hill and Smith 1984; Nowak 1994). C. senex inhabits a wide variety of ecosystems, from tropical rain forests and agroecosystems to sites with xerophilous vegetation (Watkins et al. 1972). The species is distributed from central Mexico south to western Venezuela, over elevations ranging from sea level up to 2,230 m above sea level (Snow et al. 1980; Naranjo and Espinoza 2001). Centurio senex is a strict frugivore (Snow et al. 1980; Dumont et al. 2009) and it has been suggested that it sucks the pulp from soft fruit such as Ficus sp. (Elizalde-Arellano et al. 2004), Musa sp., and Asimina triloba (Goodwin and Greenhall 1961). Little is known about most aspects of the biology of C. senex (Dumont et al. 2009). In the wild, C. senex eats Spondias radlkoferi (Anacardiaceae—Bonaccorso 1979), Drypetes lateriflora (Putranjivaceae—Snow et al. 1980), Ficus sp. (Moraceae—Gardner 1977), Guettarda foliacea (Rubiaceae— Giannini and Kalko 2004), Vitex mollis (Lamiaceae—Ramı́rezPulido and López-Forment 1979; Ceballos and Oliva 2005), and Maclura tinctoria (Moraceae—Dumont et al. 2009). Recently, it was proposed that C. senex is a frugivore specializing on hard fruit. Compared to other frugivores of similar size (e.g., Carollia perspicillata with a bite strength of 5.6 newtons [N] 6 1.69 SE—Freeman and Lemen 2010), C. senex possesses a stronger bite (10.9 6 0.85 N—Dumont et al. 2009). This specialization, however, has not been tested. We report for the 1st time that Sideroxylon capiri (Sapotaceae) forms part of the diet of C. senex, and provide evidence that supports the hypothesis that C. senex eats harder fruit than do other frugivorous bat species. MATERIALS AND METHODS From June 2009 to March 2010 we carried out a study of the bat assemblage composition (research permit FLO.FAU-026) in patches of semideciduous seasonal forest (sensu Miranda and Hernández-X. 1963) and agroecosystems in the municipality of Tlaltetela, Veracruz, Mexico (19817 0 52.083 00 N, 96842 0 27.313 00 W—Madrid-López 2010). The elevation of the study area is 523 m above sea level and the climate in the area is type Aw 00 (W)(i)g (Garcı́a 1981), which is a warm subhumid climate with summer rains and a dry season from November to March (Servicio Meteorológico Nacional 2000). With a sampling effort of 28,080 m2h (Straube and Bianconi 2002), we captured 907 bats, 9 of which were C. senex (7 females and 2 males). Seven of these were caught in semideciduous seasonal forests and 2 were in mango (Mangifera indica) and www.mammalogy.org 628 Downloaded from http://jmammal.oxfordjournals.org/ by guest on November 18, 2016 Recently it was proposed that Centurio senex specializes on hard fruit because of its strong bite compared to other similar-sized frugivorous bats; however, this hypothesis has not been tested. We tested the hardness of 5 fruit species eaten by bats, including Sideroxylon capiri (Sapotaceae), here reported for the 1st time as part of the diet of C. senex. Results show that S. capiri is the hardest fruit of the species evaluated. This is the 1st evidence of C. senex eating hard fruit in the wild, which supports the theory of a skull adapted to eating hard fruit. June 2013 629 MADRID-LÓPEZ ET AL.—CENTURIO SENEX EATING SIDEROXYLON CAPIRI RESULTS FIG. 1.—Penetrometer designed to measure the hardness of fruit eaten by bats. A) Container with fine sand; B) plunger to catch the sand and transfer weight onto the fruit via C) the point (diameter ¼ 1 mm); D) container for the fruit; E) fruit; and F) digital balance. sapodilla (Manilkara zapota) agroecosystems. We documented every aspect of the biology of the bats captured, including those fruits that were carried by the bats into the nets. Following capture all bats were released at their capture site. We handled all animals in accordance with guidelines approved by the American Society of Mammalogists (Sikes et al. 2011). To compare the hardness of S. capiri relative to that of the fruit eaten by other frugivorous bat species, we simultaneously collected the ripe fruit from species of plants reported to be part On 22 January 2010 we captured several species of bats, including Artibeus lituratus, Artibeus phaeotis, and Desmodus rotundus, and a lactating female C. senex that was carrying a fruit of S. capiri in her mouth. This is the 1stt report of a fruit of Sapotaceae being eaten by C. senex. The fruits of S. capiri are fleshy, ovoid berries with a smooth, hard epicarp that ends in a fine point. These berries are 30–50 mm long and weigh, on average, 17.5 g (Table 1). When ripe, the fruit turns yellow and then red; each fruit has a single ovoid seed, 17.5–24 mm long, that is brown, with a hard, smooth, shiny seed coat. We collected the fruits of 4 plant species (Table 1) reported to have been eaten by bats, along with the fruit of S. capiri, for which there were no previous records of it as part of the diet of bats. Fruit hardness differed among species (F4,44 ¼ 59.88, P , 0.01), with S. capiri the hardest of the 5. There were 3 degrees of hardness: Spondias purpurea and Brosimum alicastrum had the softest fruit (Fig. 2), whereas fruits of S. capiri were the hardest. DISCUSSION The fruits of S. capiri have a soft juicy mesocarp, but the epicarp is hard. Inclusion of S. capiri in the diet of C. senex TABLE 1.—Epicarp hardness of fruit eaten by bats. Sample size (n) and mean and standard deviation of the measurements taken from 10 fruits of each species are given. Hardness is expressed in newtons (N). With the exception of Sideroxylon capiri, the species were confirmed as having been eaten by bats based on the criteria of Geiselman et al. (2002). Sp pu, Spondias purpurea; Br al, Brosimum alicastrum; Ph sp, Physalis sp.; So um, Solanum umbellatum; Si ca, Sideroxylon capiri. Plant species n Sp pu Br al Ph sp So um Si ca 10 9 10 10 10 Mass (g) 6.20 4.88 1.60 1.40 17.5 6 6 6 6 6 1.13 1.05 0.51 0.51 5.38 Length (mm) 25.77 21.43 15.01 12.76 38.95 6 6 6 6 6 1.03 0.77 1.42 1.48 4.33 Width (mm) 21.76 18.34 13.58 12.30 29.41 6 6 6 6 6 1.31 0.92 1.77 1.43 2.90 Hardness (N) 0.80 0.82 1.41 1.66 2.23 6 6 6 6 6 0.15 0.32 0.19 0.22 0.28 Downloaded from http://jmammal.oxfordjournals.org/ by guest on November 18, 2016 of the diet of frugivorous bats (Geiselman et al. 2002). The species were identified by comparing specimens with those in the XAL herbarium at the Instituto de Ecologı́a, A. C. Fruit hardness was defined as the force necessary to pierce the epicarp of the fruit with a blunt point 1 mm in diameter. We designed a penetrometer (Fig. 1) to record the mass in grams necessary for the point to puncture the fruit’s epicarp. The value obtained in grams was converted to newtons (N) using the formula: F ¼ m 3 a, where F is the force in newtons, m is mass in kilograms, and a is acceleration in meters per seconds squared (m/s2); we used the value of acceleration due to gravity (9.806 m/s2). To determine differences in hardness, the fruits were weighed, measured (width and length), and tested with the penetrometer. Three trials were run for each individual fruit and the mean of these was used as the representative value for each fruit. Ten fruits were used for each of the 5 plant species. A 1-way analysis of variance and Tukey’s test were used to detect any differences in fruit hardness among species (Zar 1999). All analyses were performed in R-system software (R Development Core Team 2007). 630 Vol. 94, No. 3 JOURNAL OF MAMMALOGY agrees with the suggestion made by Dumont et al. (2009). Based on bite strength and observations of foraging by C. senex in captivity, Dumont et al. (2009) suggested that the diet of this species could include hard fruits that would separate the diet of this species from that of other frugivores. Our results also support the proposal by Freeman (1988), who stated that the shape of the cranium of C. senex suggests that this species may reflect a durophagous mode of feeding. It is quite probable that the powerful mandibles of this bat, together with the long cutting edges of its molars, are able to penetrate the epicarp of hard fruits such as those of S. capiri. The bat can then squeeze out the pulp, extract the sugar-rich juice, and spit out the indigestible fiber; however, this strategy requires verification (Morrison 1980; Freeman 1988; Dumont et al. 2009). This ability would give C. senex access to resources that are in less demand and a certain advantage when food is scarce. Other bat species deal with this by switching from frugivory to insectivory, or from nectarivory to insectivory (Gardner 1977), or by migrating to different feeding sites. Moreover, the observation of C. senex transporting a fruit of S. capiri indicates that, like other phyllostomids, this species is capable of transporting the fruit it eats to nocturnal feeding refugia that are generally at some distance (20–250 m) from the tree where the fruit was picked up (Galindo-González 1998). This implies that C. senex is likely to be a disperser of seeds of S. capiri. The mean mass of fruit of S. capiri (17.5 g; Table 1) is equivalent to at least 60% of the body mass of an adult C. senex (17–28 g—Nowak 1994), and is indicative of this species’ capacity to carry heavy loads relative to its size. This finding refutes the idea that C. senex is a bat that only eats very ripe, extremely soft or even rotting fruit (Bonaccorso 1979), or that it must eat this fruit directly from the ground or from the plant because of its inability to transport the fruits (Paradiso 1967; Freeman 1988). RESUMEN Recientemente se planteó que Centurio senex se especializa en frutos duros, ya que posee una fuerte mordida comparada con otros murciélagos frugı́voros de talla similar; aunque no se ha probado. Pusimos a prueba la dureza de 5 especies de frutos consumidos por murciélagos, incluyendo Sideroxylon capiri (Sapotaceae), que reportamos por primera vez en la dieta de C. senex. Los resultados muestran que S. capiri es la especie con semilla más dura de las estudiadas. Esta es la primera evidencia del consumo de un fruto duro por C. senex en la naturaleza, lo cual apoya la teorı́a de un cráneo adaptado para el consumo de frutos duros. ACKNOWLEDGMENTS We thank A. Tepatlán and N. Hernández for their valuable help with the fieldwork. We are thankful to the inhabitants of the Coetzala community, especially A. Durán, for their hospitality. The Instituto de Biotecnologı́a y Ecologı́a Aplicada of Universidad Veracruzana provided logistical support. R. A. Medellı́n and V. J. Sosa provided insightful comments that improved the quality of the manuscript. This study was partly funded by the Universidad Veracruzana awarded to JG-G for being in the Sistema Nacional de Investigadores (National Researches System) and a Consejo Nacional de Ciencia y Tecnologı́a (National Council for Science and Technology) postdoctoral scholarship to AAC-L. LITERATURE CITED AGUIRRE, L. F., A. HERREL, R. VAN DAMME, AND E. MATTHYSEN. 2002. Ecomorphological analysis of trophic niche partitioning in a tropical savannah bat community. Proceedings of the Royal Society of London, B. Biological Sciences 269:1271–1278. BONACCORSO, F. J. 1979. Foraging and reproduction in a Panamanian bat community. Bulletin of the Florida State Museum. Biological Sciences 24:359–408. CEBALLOS, G., AND G. OLIVA (coords.). 2005. Los mamı́feros silvestres de México. Fondo de Cultura Económica—Comisión Nacional Para Downloaded from http://jmammal.oxfordjournals.org/ by guest on November 18, 2016 FIG. 2.—Hardness (X̄ 6 SE) of the fruit belonging to 5 species eaten by bats in the region of Apazapan, Veracruz, Mexico. Different letters indicate significant differences (P , 0.01). Sp pu, Spondias purpurea; Br al, Brosimum alicastrum; Ph sp, Physalis sp.; So um, Solanum umbellatum; Si ca, Sideroxylon capiri. It is important to highlight the fact that there is only 1 report of fruit of S. capiri being eaten by A. jamaicensis, when S. capiri was known by its synonym Mastichodendron capiri (Orozco-Segovia and Vázquez-Yañes 1982). This is a potentially important point, because no other frugivore is known to do so. A. jamaicensis weighs 36–48 g (Ortega and Castro-Arellano 2001), more than double the weight of C. senex. The strength of its bite also is greater than that of C. senex (24.96 6 8.53 N—Aguirre et al. 2002), and thus is strong enough to pierce the epicarp of this fruit. Our results demonstrate that C. senex is capable of eating fruits that are harder than the mean hardness of the fruit eaten by similar-sized phyllostomid frugivores. This supports the proposal that this species has a skull adapted to eating hard fruit, which confers an advantage on C. senex concerning niche separation from other frugivorous bats when food is scarce and eventually toward the specialization of eating fruits with hard epicarp, and also means that C. senex is a genuine disperser of seeds of S. capiri. June 2013 MADRID-LÓPEZ ET AL.—CENTURIO SENEX EATING SIDEROXYLON CAPIRI MORRISON, D. W. 1980. Efficiency of food utilization by bats. Oecologia 45:270–273. NARANJO, E. J., AND E. ESPINOZA. 2001. Los mamı́feros de la Reserva Ecológica Huitepec, Chiapas, México. Revista Mexicana de Mastozoologı́a 5:58–67. NOWAK, R. M. 1994. Walker’s bats of the world. Johns Hopkins University Press, London, United Kingdom. OROZCO-SEGOVIA, A., AND C. VÁZQUEZ-YAÑES. 1982. Plants and fruit bat interactions in a tropical rain forest area, southeastern Mexico. Brenesia 19/20:137–149. ORTEGA, J., AND I. CASTRO-ARELLANO. 2001. Artibeus jamaicensis. Mammalian Species 662:1–9. PARADISO, J. L. 1967. A review of the wrinkle-faced bat (Centurio senex Gray) with description of a new subspecies. Mammalia 31:595–604. RAMÍREZ-PULIDO, J., AND W. LÓPEZ-FORMENT. 1979. Additional records of some Mexican bats. Southwestern Naturalist 24:541–544. R DEVELOPMENT CORE TEAM. 2007. R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. http://www.R-project.org. Accessed 26 July 2012. SERVICIO METEOROLÓGICO NACIONAL. 2000. Normales climatológicas 1971–2000. Estación: 00030367 Apazapan (CFE). Servicio Meteorológico Nacional, Veracruz, Mexico. SIKES, R. S., W. L. GANNON, AND THE ANIMAL CARE AND USE COMMITTEE OF THE AMERICAN SOCIETY OF MAMMALOGISTS. 2011. Guidelines of the American Society of Mammalogists for the use of wild mammals in research. Journal of Mammalogy 92:235–253. SNOW, J. L., J. K. JONES, JR., AND W. D. WEBSTER. 1980. Centurio senex. Mammalian Species 138:1–3. STRAUBE, F. C., AND G. V. BIANCONI. 2002. Sobre a grandeza e a unidade utilizada para estimar esforço de captura com utilição de redes-de-neblina. Chiroptera Neotropical 8:150–152. WATKINS, L. C., J. K. JONES, JR., AND H. H. GENOWAYS. 1972. Bats of Jalisco, Mexico. Special Publications, The Museum, Texas Tech University 1:1–44. ZAR, J. H. 1999. Biostatistical analysis. 4th ed. Prentice-Hall Inc., Upper Saddle River, New Jersey. Submitted 29 August 2012. Accepted 21 January 2013. Associate Editor was Victor Sánchez-Cordero. Downloaded from http://jmammal.oxfordjournals.org/ by guest on November 18, 2016 el Conocimiento y Uso de la Biodiversidad, México, Distrito Federal, México. DUMONT, E. R., A. HERREL, R. A. MEDELLÍN, J. A. VARGAS-CONTRERAS, AND S. E. SANTANA. 2009. Built to bite: cranial design and function in the wrinkle-faced bat. Journal of Zoology (London) 279:329– 337. ELIZALDE-ARELLANO, C., E. URÍA-GALICIA, AND J. C. LÓPEZ-VIDAL. 2004. Estructura anatómica e histológica de la lengua del murciélago frugı́voro Centurio senex (Chiroptera: Phyllostomidae). Acta Zoológica Mexicana (Nueva Serie) 20:31–37. FREEMAN, P. W. 1988. Frugivorous and animalivorous bats (Microchiroptera)—dental and cranial adaptations. Biological Journal of the Linnean Society 33:249–272. FREEMAN, P. W., AND C. A. LEMEN. 2010. Simple predictors of bite force in bats: the good, the better, and the better still. Journal of Zoology (London) 282:284–290. GALINDO-GONZÁLEZ, J. 1998. Dispersión de semillas por murciélagos: su importancia en la conservación y regeneración del bosque tropical. Acta Zoológica Mexicana (Nueva Serie) 73:57–74. GARCÍA, E. 1981. Modificaciones al sistema de clasificación climático de Köppen. Offset Larios, México, Distrito Federal, México. GARDNER, A. L. 1977. Feeding habits. Pp. 293–350 in Biology of bats of the New World family Phyllostomatidae, part II (R. J. Baker, J. K. Jones, Jr., and D. C. Carter, EDS.). Special Publications, The Museum, Texas Tech University 13:1–364. GEISELMAN, C. K., S. A. MORI, AND F. BLANCHARD. 2002. Database of Neotropical bat/plant interactions. Updated 2007. http://www.nybg. org/botany/tlobova/mori/batsplants/database/dbase_frameset.htm. Accessed 29 February 2012. GIANNINI, N. P., AND E. K. V. KALKO. 2004. Trophic structure in a large assemblage of phyllostomid bats in Panama. Oikos 105:209–220. GOODWIN, G. G., AND A. M. GREENHALL. 1961. A review of the bats of Trinidad and Tobago. Bulletin of the American Museum of Natural History 122:191–301. HILL, J. E., AND J. D. SMITH. 1984. Bats, a natural history. University of Texas Press, Austin. MADRID-LÓPEZ, S. M. 2010. Abundancia, diversidad y composición de murciélagos en fragmentos de selva mediana subcaducifolia y cultivos de árboles frutales en la región de Apazapan, Veracruz. B.S. thesis, Universidad Veracruzana, Veracruz, Mexico. MIRANDA, F., AND E. HERNÁNDEZ-X. 1963. Los tipos de vegetación de México y su clasificación. Boletı́n de la Sociedad Botánica de México 28:29–179. 631