Comparative efficiency of photographs and videos for individual identification of the Andean bear (Tremarctos ornatus) in camera trapping

Adriana Reyes, Daniel Rodríguez, Nicolás Reyes-Amaya, Daniela Rodríguez-Castro, Hector Restrepo, Marcos Urquijo

Resumen


Identification of Andean bear (Tremarctos ornatus) specimens is essential for obtaining demographic estimates of their populations. Camera traps are a noninvasive tool that allows such identification. The efficiency of using photographic or video records for identifying specimens of this species in a wild population in Colombia was compared. A total of 18 camera traps were operated from November 2011 through November 2013; each sample station included a single camera at 0.6 m height, with a bait placed 2 m in front of it at 1.5 m height. Four key external morphological features were chosen for identifying the specimens: Presence, shape and colour of facial; presence, shape and colour of pectoral markings; estimated body size; and sex. For each recording event, a visual file (photograph or video) was scored as ¨good¨ if it showed at least three key identification features, thus allowing the correct identification of the specimen; or as ¨bad¨ if it showed fewer than three features, making identification impossible. Successful recording events were those that included at least one good visual file (photograph or video). A total of 4,588 visual files were obtained: 4,324 photographs in 325 recording events and 264 videos in 260 recording events. 5.25 % of the photographs and 53.03 % of the videos were scored as good files. 26.77 % of the photograph-based and 49.62 % of the video-based recording events were successful. There were statistically significant differences between the percentage of good photographs and good videos obtained every time a camera trap was activated in the presence of a bear (Mann-Whitney, P = 1.37E-11). The low percentage of successful recording events obtained with photographs (26.77 %) compared to that obtained with videos (50.38 %), is consistent with results previously reported for this same species in Ecuador using photographs (25 %). The higher percentage of good videos (53.03 %) compared to that of good photographs (5.25 %), is consistent with the statistically significant difference found between the percentage of good photos and good videos obtained every time a camera trap was activated in the presence of a bear (Mann-Whitney, P = 1.37E-11), and with results previously reported for the Asian black bear (Ursus thibetanus, 70 %) using sample stations including a single camera trap with video format. The use of video for recording Andean bear specimens allows the observation of individuals from different viewpoints and distances, even with the use of sample stations including a single camera trap, thus minimizing the effect of light reflection on the recognition of key identification features. Additionally, the video format allowed recognition of particular physical conditions, such as limp or rigid limbs in some specimens, which cannot be recognized in photographs. In this study case, information obtained with video records provides a greater ability to recognize individual marks in the specimens and to identify them.


Palabras clave


Andean bear; camera trapping; Colombian Andes; specimen identification.

Texto completo:

PDF HTML

Referencias


Aguilar, M., and J. O., Rangel-Ch. 1996. Clima de alta montaña en Colombia. Pp. 73-130 in El páramo: ecosistema a proteger. Serie Montañas Tropoandinas II (Aguilar, M., and J. O. Rangel-Ch, eds.). Fundación de Ecosistemas Andinos (ECOA). Bogotá, Colombia.

Cardillo, M., A. Purvis, W. Sechrest, J. L. Gittleman, J. Bielby, and G. M. Mace. 2004. Human population density and extinction risk in the world’s carnivores. PLoS Biology 2:909-914.

Castellanos, A. 2011. Andean bear home ranges in the Intag region, Ecuador. Ursus 22:65-73.

Cleef, A. M. 1978. Characteristics of neotropical paramo vegetation and its subantarctic relations. Pp. 365-390 en Geoecological relations between the southern temperate zone and the tropical mountains (Troll, C., and W. Lauer, eds.). Erdwiss Forsch. Wiesbaden, Germany.

Del Moral, F., and E. Bracho. 2009. Indicios indirectos de la presencia del oso andino (Tremarctos ornatus, Cuvier, 1825) en el noroeste de Argentina. Revista Museo Argentino de Ciencias Naturales 11:69-76.

Foster, R. J., and B. J. Harmsen. 2012. A critique of density estimation from camera-trap data. Journal of Wildlife Management 76:224-236.

García-Rangel, S. 2012. Andean bear Tremarctos ornatus natural history and conservation. Mammal Review 42:85-119.

Higashide, D., S. Miura, and H. Miguchi. 2013. Evaluation of Camera-Trap Designs for Photographing Chest Marks of the Free-Ranging Asiatic Black Bear, Ursus thibetanus. Mammal Study 38:35-39.

Instituto Nacional de los Recursos Naturales Renovables (Inderena). 1986. Parques Nacionales, Instituto Nacional de Recursos Naturales, Fondo FEN. Bogotá, Colombia.

Jones, T. 2010. Detection probability and individual identification of the Andean Bear (Tremarctos ornatus) using camera trapping methods. Master Thesis, University of Wisconsin. Madison, U. S. A.

Peyton, B. 1980. Ecology, distribution, and food habits of spectacled bears, Tremarctos ornatus in Peru. Journal of Mammalogy 61:639-52.

Peyton, B. 1999. Spectacled bear conservation action plan. Pp. 157-198 in Bears, status survey and conservation action plan (Servheen, C. S., S. Herrero, and B. Peyton, eds.). IUCN/SSC Bear and polar bear specialist group. Gland, Switzerland.

Rangel-Ch, J. O. 2000. Clima de la región paramuna. Pp. 85-125 in La región de vida paramuna. Colombia diversidad Biótica III (Rangel-Ch, J. O, ed.). Universidad Nacional de Colombia, Facultad de Ciencias, Instituto de Ciencias Naturales. Bogotá, Colombia.

Reyes-Amaya, N. 2015. Familia Ursidae. Pp. 166-171 in Los carnívoros terrestres y semiacuáticos continentales de Colombia (Suárez-Castro, A. F., and H. E. Ramírez-Cháves, eds.). Universidad Nacional de Colombia. Bogotá, Colombia.

Ríos-Uzeda, B., H. Gomez, and R. B. Wallace. 2007. A preliminary density estimate for Andean bear using camera-trapping methods. Ursus 18:124-128.

Rodríguez, D., F. Cuesta, I. Goldstein, L. Naranjo, and O. Hernández. 2003. Estrategia ecorregional para la conservación del oso andino Tremarctos ornatus en los Andes del norte. WWF, Fundación Wii, Ecociencia, Wildlife Conservation Society. Bogotá, Colombia.

Rodríguez, D. 2006. Manual de identificación de rastros y huellas de oso andino en los páramos y bosques andinos en Colombia. Fundación para la Investigación, Conservación y Protección del Oso Andino (Wii). Bogotá, Colombia.

Roth, H. 1964. Ein Beitrag zur Kenntis von Tremarctos ornatus (Cuvier) Der. Zoologische Garten 29:107-129.

Stern, S. J. 1998. Field studies of large mobile organisms: scale, movement and habitat utilization. Pp. 289-307 in Ecological scale: theory and applications (Peterson, D. L., and V. T. Parker, eds.). Columbia University Press. New York, U. S. A.

Vargas, O., and P. Pedraza. 2004. Parque Nacional Natural Chingaza. Departamento de Biología, Universidad Nacional de Colombia. Bogotá, Colombia.

Van Horn, R. C., B. Zug, C. Lacombe, X. Velez-Liendo, and S. Paisley. 2014. Human visual identification of individual Andean bears Tremarctos ornatus. Wildlife Biology 20:291-299.

Zug, B. 2009. Individual identification and habitat use of Andean bears on private lands in the Ecuadorian Andes. Master Thesis. University of Wisconsin. Madison, U. S. A.


Enlaces refback

  • No hay ningún enlace refback.


Therya es publicada por la Asociación Mexicana de Mastozoología A. C.  Se distribuye bajo una Licencia de Creative Commons Atribución-NoComercial-SinDerivar 4.0 Internacional.

DERECHOS DE AUTOR Y DERECHOS CONEXOS, THERYA es una publicación cuatrimestral editada por la Asociación Mexicana de Mastozoología A. C.  Hacienda Vista Hermosa 107, Colonia Villa Quietud, Coyoacan 04960.  Distrito Federal, México.  Telefono (612) 123-8486, www.mastozoologiamexicana.org.  Editor responsable: Dr. Sergio Ticul Álvarez Castañeda (therya@cibnor.mx).  Reservas de Derechos al Uso Exclusivo No. 04-2009-112812171700-102, ISSN: 2007-3364 ambos otorgados por el Instituto Nacional de Derechos de Autor.  Responsable de la última actualización de este número, Unidad de informática de la Asociación Mexicana de Mastozoología A. C.  Dr. Sergio Ticul Álvarez Castañeda.  Instituto Politécnico Nacional 195.  La Paz, Baja California Sur, C. P. 23096.  Tel 612 123 8486.

Las opiniones expresadas por los autores no necesariamente reflejan la postura del editor de la publicación.  Queda prohibida la reproducción total o parcial de los contenidos e imágenes de la publicación sin previa autorización de la Asociación Mexicana de Mastozoología, A. C.