CIENCIAS EXACTAS Y NATURALES-Artículo Científico

VEHICLE COLLISIONS WITH WILD FAUNA ON THE TWO ROADS THAT PASS THROUGH THE MONTES DE MARÍA, SUCRE, COLOMBIA

ATROPELLAMIENTO DE FAUNA SILVESTRE EN LAS DOS VÍAS QUE CIRCUNDAN LOS MONTES DE MARÍA, SUCRE, COLOMBIA

Orlando De La Ossa-Nadjar¹, Jaime De La Ossa V.²

¹Magister en Ciencias Ambientales. SUE-Caribe, Universidad de Sucre, Colombia, e-mail: o.delaossa@hotmail.com

² Ph.D., Grupo de Investigación en Biodiversidad Tropical. Universidad de Sucre, Colombia. Calle 13ª N° 20-45 Apto. 402, Edif. El Cairo, Barrio Ford, Sincelejo, Sucre, e-mail: jaimedelaossa@yahoo.com

Rev. U.D.C.A Act. & Div. Cient. 18(2): 503-511, Julio-Diciembre, 2015

ABSTRACT

The present study aimed to identify and quantify the wild fauna that is struck by vehicles on the two principal roads that run through the Montes de María in the department of Sucre, Colombia. This study addressed some of the environmental problems that are affecting the dry tropical forest area that is still found in this Caribbean zone of Colombia. Between October of 2011 and March of 2012, encompassing the dry and the rainy seasons, on the roads between Sincelejo - San Onofre and between Sincelejo - Ovejas, 608 vehicle-struck or "road-kill" specimens were collected, which were identified to the extent possible (order, family, genus, species). A Fisher test and analysis of variance were used to analyze the data. The vehicle-struck fauna were found on the principal roads that run through the Montes de María in the department of Sucre in this study and had notable representation from the following: amphibians (Rhinella marina, Leptodactylus bolivianus, Scinax sp.); reptiles (Leptodeira septentrionalis, Pseudoboa neuwiedii, Epicrates cenchria, Oxyrhopus petola, iguana iguana, Kinosternon scorpioides, Trachemys callisrostris); and mammals (Didelphis marsupialis, Tamandua mexicana, Cerdocyon thous), with a total of 253, 219 and 111 specimens, respectively. The dry season had more vehicle-struck specimens, with a high percentage seen on both roads, which may have been related to the scarcity of food in this season, forcing the animals to travel longer distances and cross the roads.

Key words: Collisions, native fauna, dry forest, Caribbean, Sucre.

RESUMEN

El objetivo del presente trabajo fue identificar y cuantificar la fauna silvestre atropellada en las dos principales vías que rodean los Montes de María, en el departamento de Sucre, Colombia. Este estudio aborda parte de la problemática ambiental que afecta la zona circundante del bosque seco tropical, que aún persiste en esta zona del Caribe colombiano. Entre octubre de 2011 y marzo de 2012, época de lluvia y de sequía en las vías: Sincelejo-San Onofre y Sincelejo-Ovejas, se recolectaron 608 especímenes atropellados; a los especímenes colectados, se les realizó la identificación, hasta donde fue posible (orden, familia, genero, especie). Para el análisis de datos, se aplicó el test de Fisher y análisis de varianza. Entre la fauna silvestre atropellada, que mayormente prevaleció en las principales vías que rodean los Montes de María, en el departamento de Sucre, durante las épocas de lluvias y sequía, se destacan: anfibios (Rhinella marina, Leptodactylus bolivianus, Scinax sp.); reptiles (Leptodeira septentrionalis, Pseudoboa neuwiedii, Epicrates cenchria, Oxyrhopus petola, iguana iguana, Kinosternon scorpioides, Trachemys callisrostris) y mamíferos (Didelphis marsupialis, Tamandua mexicana, Cerdocyon thous), con un total de 253, 219 y 111 especímenes, respectivamente. La época, que tuvo mayor prevalencia de atropellamientos, fue la de sequía. El alto porcentaje de atropellamientos evidenciado en la época de seca -para ambas vías-, se puede relacionar con la escasez de alimento, ya que los animales se ven obligados a recorrer mayores distancias exponiéndose a la carretera.

Palabras clave: Colisión, fauna nativa, bosque seco, Caribe, Sucre.

INTRODUCTION

Road networks are vital to the socioeconomic development of regions because they allow for improvements in the quality of life of local inhabitants, facilitate the transport of people, and are used to carry products to market (Arroyave et al . 2006). However, roads also impact the ecology of the areas they pass through; for example, they alter the hydric cycle, increase the production of particulate material and noise, decrease the population of flora and fauna, create microclimate changes, and contaminate the soil and water (Arroyave et al . 2006; Messmer et al . 2008). Furthermore, roads can isolate and fragment the habitat of diverse populations of plants and animals, the latter of which must cross these roads, which increases the probability that they will be struck by a vehicle (Messmer et al . 2008).

Several studies that have been conducted in South America, Europe, and the United States have revealed disturbing data for the number of vehicle-struck animals and the threat that this situation represents for some species that are in danger of extinction (Aresco, 2005; Rosa & Mahus, 2005; Gumier & Sperber, 2009). Studies carried out by Pinowski (2005) indicated that there are patterns for vehicle-struck animals that are related to the type of vegetation, climatic conditions, and the behavior of these species, with a high incidence of vehicle strikes in opossums (Didelphis marsupialis), foxes (Cerdocyon thous) and various snake species, among others .

It has been documented that vehicle strikes with wild fauna occur in relation to climatic periods because they coincide with reproduction periods and the low availability of food, which increase the probability that animals will cross roads, thereby generating higher probabilities for vehicle strikes, a grave situation for species that are endangered or that have a restricted distribution (Erritzoe et al . 2004; Langley et al . 2006; Ramp et al . 2006; Glista et al . 2009). The rapid development of cities and increases in human populations have increased road networks, giving rise to a new cause of animal mortality that has become an increasingly greater threat for the affected species (Arroyave et al . 2006).

All roads, in addition to facilitating transport, commerce, and development, affect terrestrial and aquatic ecosystems in the following ways: a) they increase the mortality of organisms when constructed and the mortality of animals that are commonly struck on the roads; b) alter animal behavior; c) change the chemical makeup of the environment and d) serve as a corridor for the dispersion of foreign species and increase the alteration or use of natural habitats by humans (Trombulak & Frissell, 2000). Cupul (2002) described certain patterns of seasonal behavior, such as courtship, migration, reproduction, mating, abundance of animals, and the search for food, among others, that make it possible for there to be a higher or lower quantity of dead animals on roads in determined periods of the year.

In Colombia, there have been few studies that have measured the frequency of vehicle strikes on roads (Arroyave et al. 2006; Delgado, 2007; Vargas-Salinas et al. 2011), usually there are only journalistic reports. It is clear that vehicle strikes decrease the population of wild fauna, interfere with the flow of genetics and trophics, and debilitate the natural system, factors that lead to local extinction over time (Gumier & Sperber, 2009). The present study allowed for the comparative identification and quantification of the mortality of wild fauna that results from vehicle strikes on the two principal roads that pass through the Montes de María, Sucre, Colombia: between Sincelejo-San Onofre and between Sincelejo-Ovejas.

MATERIALS AND METhODS

Study area: Two roads in the department of Sucre, Colombia were studied. One of the roads is a principal western artery between the points: 9°15'36'' N and 75°24'12''W - 9°31'55''N and 75°13'14''W and connects the populations of Sincelejo and Ovejas, and the other road is a branch from the western artery between the points: 9°15'36''N and 75°24'12''W 9°52'19''N and 75°23'08''W and connects the city of Sincelejo to the village of San Onofre. Neither road has illumination on the majority of their routes. They have an average width of 8m and are relatively flat. Both of the studied sections are paved and lack signs or infrastructure for the protection of the wild fauna (Figure 1).

Method: Between October of 2011 and March of 2012, which included a dry season and a rainy season, simultaneous and continuous samples of vehicle-struck fauna were taken. The paved roads included 62.71km between Sincelejo and San Onofre and 36.59km between Sincelejo and Ovejas. The protocol established by Hawbaker & Radeloff (2004), Arroyave et al . (2006), Coffin (2007), and Gumier & Sperber (2009), was followed.

The tasks included: placing six observers along the roads, three per section, who visually searched for animals found on the road and the shoulder during the hours of Monday to Saturday from 5 am to 9am, traveling at an average speed of 15km/h on motorcycles; the collected specimens were photographed and geo-referenced for location; subsequently, they were taken to the wild fauna office, Fauna Silvestre de CARSUCRE, where they were identified taxonomically; the following toll booths were used to count the vehicles and quantify the traffic volumes: la Esperanza, located in the municipality of Toluviejo (road between Sincelejo - San Onofre); and Las Flores, located in the municipality of Corozal (road between Sincelejo - Ovejas).

For each collection, when the conditions allowed it, the sex and maturity stage were identified. Depending on the state they were found in, the samples were systematically identified as much as possible. For the analysis of the data, a Fisher test and analysis of variance with confidence intervals of 95% were applied (Zar, 1999).

RESULTS AND DISCUSSION

Table 1 contains a list of the vehicle-struck species by road. The majority of the vehicle-struck species was found on the Sincelejo - Ovejas road, rather than the Sincelejo - San Onofre road. Table 2 shows the percentages of vehiclestruck animals by taxon during the two seasons of the year, independent of the sampled road, and table 3 presents the percentage of vehicle-struck fauna by taxon for each of the studied roads.

For the herpetofauna, on both roads, the dry season months (February and March) presented the higher number of vehicle-struck specimens; however, in the dry season, the Sincelejo - Ovejas road had the highest number in November and the Sincelejo - San Onofre road had the highest number in October. For birds, especially on the Sincelejo - Ovejas road, the collisions increased in November, at the end of the rainy season, and, between January and February, during the dry season. For mammals, on both roads, the vehicle strikes increased in the rainy season and decreased on both roads in the dry season; the vehicle strikes increased as the rainy season progressed and the decrease in the measurements was more intense in the dry season.

In general, the herpetofauna was the taxonomic group that suffered the most vehicle strikes, which agreed with the results of Ramo & Busto (1986), Grosselet et al . (2008) and Seijas et al. (2013). Among the herpetofauna, when analyzing the list of vehicle-struck species, the amphibians presented a numeric value that contrasted with the low relative diversity that this group possesses in this region (Acosta-Galvis et al. 1999), with 18 species in the department of Sucre (Lynch et al. 1997; Lynch & Suarez, 2001).

In the present study, although the amphibians were the group with the highest volume of vehicle strikes, only three species were identified: Rhinella marina, Leptodactylus bolivianus and Scinax sp, which may have been related to feeding patterns. For example, Rhinella marina has a diet with a high content of terrestrial insects, which are abundant in open areas with deposits of organic plant material and land depressions that form small ponds, as seen on the shoulders of the roads and as seen with other vertebrates (Waide, 1991). Likewise, mobility was a factor; the amphibian species with the most vehicle strikes had a low range of movements and had terrestrial habits. The high percentage of strikes could be attributable to their vagility and opportunistic behavior and their use of the roads as a travel corridor (Vargas-Salinas et al. 2011).

When looking at the struck species by taxon, Rhinella marina had the highest position, both for its group and for all of the vehicle-struck fauna; this species has been reported as the most vehicle-struck species on Neotropical roads (Becerril-Morales, 2001; Vargas-Salinas et al. 2011; OmenaJunior et al . 2012). The vehicle strikes could be favored by the border effect (Kattan, 2002) because a species that colonizes borders is generally attracted to the favorability of barriers and changes in the trophic dynamic of a system, which increase the population of the species and, therefore, its exposure to the effects of roads.

For birds, it was observed that they were mostly opportunistic with scavenger characteristics, which made them more susceptible to vehicle strikes due to their foraging behavior (Arroyave et al . 2006). Of the birds, the scavengers Cathartidae and Falconidae suffered vehicle strikes because they were attracted to the roads in order to consume the dead animals found there (Noss, 2002); in addition, they were attracted by the organic waste left on the roads, which provided a opportunistic food source for them (Cupul, 2002).

For the insectivore mammal species, such as Tamandua mexicana, their presence among the vehicle-struck species was attributed to their formicivorous diets and to their possible increase in roadside foraging. In these open spaces, there is an increase in the accumulation of organic matter from weeds and litterfall, which results in an elevated presence of invertebrates, as indicated by Waide (1991).

Cerdocyon thous, in this study, had the highest number of vehicle strikes among the mammals and ranked third overall (Delgado, 2007). This species has a broad and opportunistic diet, making it a carnivorous scavenger (Vieira, 1996). Individuals of this species are frequently observed on the roads and it is one of the species with a higher number of vehicle-strike deaths in some low-lying areas of South America (Pinowski, 2005), as was seen in the present study.

Didelphis marsupialis, the mammal species with the second highest number of vehicle strikes, is an omnivore with opportunistic feeding habits. It has been recorded as a commonly vehicle-struck species on the roads of Antioquia, Colombia (Delgado, 2007); the high frequency of collisions could be related to its abundance (Delgado, 2007). This species has also been identified as the most vehicle-struck species for the fauna found on a road in the Amazon of Brazil (Omena-Junior et al . 2012). According to Pinowski (2005), D . marsupialis is also frequently struck in low-lying areas, as seen in the present study.

The results of this study, in which the herpetofauna was the fauna with the most vehicle strikes, differed from findings for Brazil in which: the Br-262 road in Mato Grosso do Sul and the BR-174 road in the Amazon, on which mammals had the highest representation, followed by birds, and amphibians and reptiles had low numbers (Lima, 2012; Omena-Junior et al . 2012). However, these results agreed with those of Grosselet et al . (2008) for Tehuantepec, México. The fact that the reptiles belonged to the group with the most vehicle strikes agreed with the studies conducted by Seijaset al. (2013) and Ramo & Busto (1986) for Venezuela and were similar to the results of studies conducted by Vargas-Salinas et al. (2011) in Colombia.

The adjacent habitats and the ecological formation of the roads influence the probability of vehicle strikes for determined zoological groups and also play an important role in the conservation of the existing plant matrix as well as the fundamental aspects of the distribution of the species and their population attributes. Furthermore, the collection schedule demonstrated that most of the samples came from nocturnal animals, which may suffer vehicle strikes due to the effect of headlight glare.

The analysis of variance confirmed that the factors of season and animal (taxon) had a statistically significant effect on the number of vehicle-struck animals and the road factor was statistically significant. On the other hand, the interactions: season x animal class, season x road, road x animal class, and season x road x animal class, were not statistically significant (Table 4).

For the vehicle-struck animals by taxon, the Fisher test demonstrated that there was a statistically significant difference between the means of vehicle-struck animals by taxon: birds, herpetofauna and mammals, with the herpetofauna being the animal class that suffered the most vehicle strikes (Table 5).

The season influenced the vehicle strikes; in this case, there were statistically significant differences, with more collisions in the dry season. Furthermore, the climatic factors influenced the availability of food and the reproductive period, which in turn influenced the number of vehicle strikes (Grosselet et al . 2008); similarly, foliage cover is related to the season, where the end of the rainy season and the start of the dry season see a higher production of wild fruits; the phenological periods also notably affect the composition, structure, and dynamic of ecosystems (Quigley & Platt, 2003). For Venezuela, Seijas et al . (2013) found that the transitional months between the dry season and the rainy season show a higher frequency of vehicle strikes, while Omena-Junior et al . (2012) did not find significant differences between rainfall and vehicle strikes throughout the year, which was attributable to the environmental characteristics of the studied zone, a tropical wet Amazon forest with abundant hydric resources yearround.

A traffic flow of 10,217 vehicles /day was seen on the Sincelejo - Ovejas road and 1,543 vehicles/day on the Sincelejo - San Onofre road; the number of vehicles that passed over the two roads had significant differences (p=0.049), but there were no significant differences between the two roads in terms of the number of vehicle strikes for the number of vehicles that passed over the road (p=0.7450).

Seiler (2003) proposed a model that has an indicator, Mean Daily Traffic (MDT), that points to a relatively low mortality when it is low, ≤ 2,500 per day, and to a high mortality when it is average, between 2,500 and 10,000. The results of the present study did not agree with those of Seiler (2003) because when using the Mean Daily Traffic to compare the two roads, the vehicle strikes did not have significant differences, although there was a significant difference in the number of vehicles that passed over each road/day.

It is important to mention that these results probably underestimated the dimension of the problem considering the fact that the scavenger birds, as well as the mammals, humans, and traffic flow may have displaced the carcasses (Grosselet et al . 2008). Not all of the vehicle-struck individuals were detected; some were not visible on the road because the collision may have knocked them from the road or injured them, after which they would have left the road; therefore, the actual mortality could be much higher (Bafaluy, 2000). The mortality of the fauna in the roads could be affecting the faunal species because the application of protection measures that would minimize the impact are difficult to implement, as is raising awareness in people of the damage that can be caused by their vehicles, especially when driven inappropriately (Bafaluy, 2000; Clevenger et al. 2003; Taylor & Goldingay, 2004).

Conflicts of interest: This manuscript was prepared and revised with the participation of all of the authors, who declare that there is no conflict of interest that would put the validity of these results in danger.

BIBLIOGRAPhY

1. ACOSTA-GALVIS, A.R.; CUENTAS, D.; COLOMA, L. 1999. Una nueva especie de Colostethus (Anura: Dendrobatidae) de la región del Caribe de Colombia. Rev. Acad. Col. Cienc. Exactas Fís. Nat. 23(Sup. Es):225-230.         [ Links ]

2. ARESCO, M. 2005. The effect of sex-specific terrestrial movements and roads on the sex ratio of freshwater turtles. J. Biol. Cons. (USA). 123:37-44.         [ Links ]

3. ARROYAVE, M.; GÓMEZ, C.; GUTIÉRREZ, M.; MÚNERA, D.; ZAPATA, P.; VERGARA, I. 2006. Impactos de las carreteras sobre la fauna silvestre y sus principales medidas de manejo. Rev. EIA (Colombia). 1(5):45-57.         [ Links ]

4. BAFALUY, J.J. 2000. Mortandad de murciélagos por atropello en carreteras del sur de la provincia de Huesca. Galemys (España). 12(1):15-23.         [ Links ]

5. BECERRIL-MORALES, F. 2001. Sapos atropellados: mortalidad no natural del sapo marino (Rhinella marina; Bufonidae), en Puerto Angel, Oaxaca. Ciencias y Mar (México). 5(13):47-52.         [ Links ]

6. CLEVENGER, A.P.; CHRUSZCZ, B.; GUNSON, K.E. 2003. Spatial patterns and factors influencing small vertebrate fauna road-kill aggregations. Biol. Conserv. (USA). 109:15-26.         [ Links ]

7. COFFIN, A. 2007. From roadkill to road ecology: A review of the ecological effects of roads. J. Transp. Geo. (USA). 15:396-406.         [ Links ]

8. CUPUL, F. 2002. Víctimas de la carretera: fauna apachurrada. Gaceta CUC. Departamento de Ciencias. Centro. Universitario de la Costa. México. 10p.         [ Links ]

9. DELGADO, V.C.A. 2007. Muerte de mamíferos por vehículos en la vía del Escobero, Envigado (Antioquia), Colombia. Actual Biol (Colombia). 29 (87):229-233.         [ Links ]

10. ERRITZOE, J.; MAZGAJSKI, T.; REJT, L. 2004. Bird casualties on European roads a review. Acta Ornithol. (USA). 38(2):1-9.         [ Links ]

11. GLISTA, D.; DEVAULTY, T.; DEWOODYZ, J.A. 2009. Review of mitigation measures for reducing wildlife mortality on roadways. J. Landsc. Urb. Plan. (Netherlands). 91:1-7.         [ Links ]

12. GROSSELET, M.; VILLA-BONILLA, B.; RUIZ MICHAEL, G. 2008. Afectaciones a vertebrados por vehículos automotores en 1.2 km de carretera en el istmo de Tehuantepec. Proceedings of the Fourth International Partners in Flight Conference: Tundra to Tropics (Canada). 1:227-231.         [ Links ]

13. GUMIER, F.; SPERBER, C. 2009. Atropelamentos de vertebrados na Floresta Nacional de Carajás, Pará, Brasil. Acta Amazon. (Brasil). 39(2):459-466.         [ Links ]

14. HAWBAKER, T.; RADELOFF, V. 2004. Roads and landscape pattern in Northern Wisconsin based on a comparison of four road data sources. J. Cons. Biol (USA). 18:1233-1244.         [ Links ]

15. KATTAN, G. 2002. Fragmentación: patrones y mecanismos de extinción de especies. En: Guariguata, M.R.; Kattan, G. (Eds.). Ecología y Conservación de Bosques Neotropicales. Libro Universitario Regional. (Cartago, Costa Rica). p.561-590.         [ Links ]

16. LANGLEY, R.; HIGGINS, S.; HERRIN, K. 2006. Risk factors associated with fatal animal-vehicle collisions in the United States, 1995-2004. Wild Env Med (USA). 17(4):229-239.         [ Links ]

17. LIMA, S. 2012. BR 262 continua palco de atropelamento de animais em extinção. Capital do Pantanal: Jornal Online, Noticia Regional, 26 de junho. Disponible desde internet en http://capitaldopantanal.com.br/cdp/regional/14785.html (con acceso 27/06/2012).         [ Links ]

18. LYNCH, J.D.; SUAREZ, M.A.M. 2001. The distribution of the gladiator frogs (Hyla boans group) in Colombia, with comments on size variation and sympatry. Caldasia (Colombia). 23(2):491-507.         [ Links ]

19. LYNCH, J.D.; RUIZ-CARRANZA, P.M.; ARDILA-ROBAYO, M.C. 1997. Biogeographic patterns of Colombian frogs and toads. Revista de la Academia Colombiana de Ciencias Exactas Físicas y Naturales (Colombia). 21(80):237-248.         [ Links ]

20. MESSMER, T.; DEER, J.; HUM, C. 2008. Vehicle collision statistics and mitigation information: online sources (USA). 2(1):131-135.         [ Links ]

21. NOSS, R. 2002. The ecological effects of roads. Disponible desde internet en http://www.eco-action.org/dt/roads.html (con acceso 10/06/2005).         [ Links ]

22. OMENA-JUNIOR, R.; PANTOJA-LIMA, J.; SANTOS, A.L.W.; RIBEIRO, G.A.A.; ARIDE, P.H.R. 2012. Caracterização da fauna de vertebrados atropelada na rodovia BR - 174, Amazonas, Brasil. Rev. Col. Ciencia Animal. 4(2):291-307.         [ Links ]

23. PINOWSKI, J. 2005. Roadkills of Vertebrates in Venezuela. Rev. Bras. Zool. 22(1):191-196.         [ Links ]

24. QUIGLEY, M.F.; PLATT, W.J. 2003. Composition and structure of seasonally deciduous forests in the Americas. Ecological Monographs (USA). 73:87- 106.         [ Links ]

25. RAMO, C.; BUSTO, B. 1986. Influencia de las carreteras sobre la mortalidad de la fauna silvestre en el área Guanare-Masparro. Rev. Unellez Ciencia y Tecnología (Venezuela). 4:33-38.         [ Links ]

26. RAMP, D.; WILSON, V.; CROFT, D. 2006. Assessing the impacts of roads in peri-urban reserves: Road-based fatalities and road usage by wildlife in the Royal National Park, New South Wales, Australia. J. Biol. Cons. (USA). 129(3):348-359.         [ Links ]

27. ROSA, A.; MAHUS, J. 2005. Atropelamentos de animais silvestres na rodovia RS-040. Ver. Cad. Pesq. Biol. (Brasil). 16 (1):35-42.         [ Links ]

28. SEIJAS, A.E.; ARAUJO-QUINTERO, A.; VELÁSQUEZ, N. 2013. Mortalidad de vertebrados en la carretera Guanare-Guanarito, Estado Portuguesa, Venezuela. Rev. Biol. Trop. (Costa Rica). 61 (4):1619-1636.         [ Links ]

29. SEILER, A. 2003. Ecological Effects of roads - a review. Department of Conservation Biology, Swedish University of Agricultural Sciences, Introductory Research Essay 9. Uppsala (Sweden). 42p.         [ Links ]

30. TAYLOR, B.D.; GOLDINGAY, R.L. 2004. Wildife roadkills on three major roads in North-Eastern New South wales. Wildlife Res. (Australia). 31:83-91.         [ Links ]

31. TROMBULAK, S.; FRISSELL, C. 2000. Review of ecological effects of roads on terrestrial and aquatic communities. Conserv. Biol. (USA). 14:18-30.         [ Links ]

32. VARGAS-SALINAS, F.; DELGADO-OSPINA, I.; LÓPEZ- ARANDA, F. 2011. Mortalidad por atropello vehicular y distribución de anfibios y reptiles en un bosque subandino en el occidente de Colombia. Caldasia. 33(1):121-138.         [ Links ]

33. VIEIRA, E.M. 1996. Highway mortality of mammals in central Brazil. J. Braz. Assoc. Advanc. Sci. 48:270-272.         [ Links ]

34. WAIDE, R.B. 1991. Summary of the response of animal populations to hurricanes in the Caribbean. Biotropica (USA). 23:508-512.         [ Links ]

35. ZAR, J. 1999. Biostatistical Analysis. Prentince Hall. 4^aedición. New Jersey (USA). 663p.         [ Links ]

Received: 27 May 2015 Accepted: 22 July 2015