Giant Otter (Pteronura brasiliensis) National Assessment

Transcription

1 Giant Otter (Pteronura brasiliensis) National Assessment Conservation status of Pteronura brasilienis in Guyana Zelda van der Waal Local names for the species Giant river otter (English), Turara (Makushi), Saaru (Wapishana), Eniabu peru (Arawak), Water Dog (Creole), Turáclá (Patamona). National past and present distribution Giant otters are found all across Guyana; along the coast (Berbice, Morawhanna, Mahaica, Mahaicony and Abary Rivers) as well as in the interior (Mazaruni, Potaro, Essequibo, Rewa, Burro-Burro and Rupununi Rivers). Colour code 2006-present anterior to 2002 Number code (1) renowned places for otter habitation (2) Sanderson et al., (3) Barnett et al., 2000 (sightings of 1998). (4) Iwokrama surveys of 2002, 2009, 2012, lead by respectively I. Roopsind, J. Bicknell, A. Roopsind. (5) A. Williams, WWF Guyana, personal communication. observations by J. de Freitas, (7) observations by C. Bernard, (8) Sanderson and Ignacio, (9) observations by B. Lim, personal communication. (10) Pickles et al., (11) Duplaix, (12) observations by F. Allicock, (13) observations by M. Kalamaden, (14) Bicknell et al., 2011 Figure 1: recorded sightings of Giant River Otters in Guyana from various sources, dates comprised between Map produced by A. Roopsind, Iwokrama Centre for Rainforest Conservation and Development, February 2012.

2 Documented sightings are located on the map. The colour of the points indicates how recent the recorded sightings are (red for most recent, yellow for oldest), and the associated numbers correspond to various sources. Group size is comprised between 1-5 individuals. Giant otters sightings are spread throughout the country. The North-West presents no record; which may be partly due to a lack of research, but also rests with the impacts of gold mining. Points are not representative of effort. Giant otters are thought to be seen in the South of the country more often than they used to be (Diane McTurk, 2012, personal communication); however it is unclear whether this increase is due to more individuals being present or to an increase in awareness and recording of sightings. Population, abundance, and/or density estimates Population numbers of the species have been investigated for few locations in Guyana. The population number on a national level is undetermined. Guyana is considered a major stronghold of the Giant Otters and the need for more refined distributional data in the country has been assessed a priority on several instances (Barnett et al., 2000). The South Rupununi rivers shelter many otters, the Kassikaytyu River for instance is so populated that Giant Otters can be seen at almost every visit (J. De Freitas, 2012, personal communication). They however are not quantified to this day. The Rewa Head and neighbouring creeks (65 miles above Corona Falls) count a minimum of about 35 Giant Otters divided in to 5 groups, of most were sighted on the lower Rewa (Pickles et al., 2009). Surama records about individuals on a regular basis (Allicock, personal communication, 2012). Iwokrama forest has recorded otter presence in terms of otter signs (dens, campsite and latrines) and found a density of 1.32 to 1.88 signs per kilometre on portions of the Burro-Burro, Essequibo, Rewa and Rupununi Rivers, and a lower density of 0.31 on the Siparuni River. The Karanambu area is considered a very densely populated area; during the training taking place in 2010, over 28 individual otters were counted in a 40km stretch of the Rupununi River (James, 2010). Habitat use: Giant otters are believed to be found essentially where fishing is known to be good; their distribution is thought to be dependent mainly on fish abundance. This is because Giant Otters are found in very diverse habitats. For instance along the Rupununi River near Karanambu, dens are built by one same group within both steep and slippery clay banks and sloping sand banks (personal observation, 2012 and Duplaix, 2004). The holts are dug within the river banks, often taking advantage of holes created by the roots of trees. Holts are surrounded by various types of vegetation such as mixed marsh and high swamp forest, low marsh forest, or oxbow lakes and ponds along the Rupununi (Duplaix, 2004) or Mora seasonally flooded forest along the Essequibo (personal observation, 2012). During the rainy seasons, Giant Otters are reportedly not seen by the communities. In the northern part of the country, the first rainy season occurs from mid-april to the end of July, then the second wet season is between mid-november and the end of January; in the southern part there is only one extended wet season from mid-april to mid-september (Hydromet Guyana, 2012). It appears that the habitat of Giant Otters is not determined during these periods. Human (historical and current) threats and associated mortality: Direct human threats to the Giant River Otter are low and are believed to be now responsible for an anecdotic number of mortalities. Until 1975, Giant Otters were trapped for their skins; there is records of skins being bought in Aranaputa Village (NRBB, 2000, unpublished) to make bags and belts sold in town. In 2001, Giant Otters were reported as hunted along the Canje River and in eastern Guyana near

3 some of the bauxite mines (Barnett et al., 2001). The claws are also seen as a protection during menstruation, as Bina for a safe journey, and being good at fishing. Hunters were known to shoot them after having called them, mostly as an entertainment. Hunters used a gun or smoked the otters out of their burrows using a mixture made with pepper (Chikati, NRDDB, 2000, unpublished). These practices were very serious to giant otter populations as they induced the death of the whole family at once. Hunting became forbidden in 1968 and the reinforcement by government rangers and patrols proved efficient. Gold mining may be the most important threat to Giant Otters. The gold-mining sector in Guyana represented 11,000 persons in 2004, and has been on the increase since (Hays and Vieira, 2004). Mining is a threat via water pollution. Gold mining is associated with high mercury production on the site of exploitation. Areas in the vicinity of gold mining activity were sampled in the past in Guyana in both humans and fish; mercury levels were found higher than the amount considered safe on several occasions (including Duplaix, 2004 and Hays and Vieira, 2001), with this level increasing with higher fish consumption. This implies a level of mercury at least as unsafe for Giant Otters, who live in the rivers, feed on fish only and are in constant contact with sediments. Oil industry, hydroelectric development, overfishing, destruction of riparian habitat, diseases are not documented but are not considered high threats in Guyana. Conflicts with fishermen exist and make the Giant Otters perceived as pests, but only by a minority of villagers nowadays. Otters are very efficient at fishing; they eat all day long and feed largely on Arawana, Lukanani, Yakutu, Perai, Paku and Tiger Fish. These species are equally appreciated by villagers, which make them direct competitors. It is said that when Turara are around, the fish do not bite hooks (NRDDB, 2000, unpublished), which still causes some individual otters to be shot occasionally. Live capture is done on young Giant Otters in order to keep them as pets. However they usually get undesirable as they grow up and feed more importantly, and do not behave peacefully when captive (NRDDB, 2000, unpublished), and often get killed or chased. Giant river otters are perfect candidates for ecotourism activities, however no regulation currently exists as to how to preserve the animals from such human presence. Impacts in Guyana are not documented, with one of the most densely occupied area being also the most known Giant Otter watching destination in the country, Karanambu ranch. Climate change is mentioned as an important factor via extended La Nina conditions (as in recent years, La Nina extended until March), which result in high rainfall and water levels in Guyana. The use of the river is known to change given water level, hence impacting habitat use of the Giant Otters, although the precise consequences are not determined. Increased intrusion of tidal water into freshwater is also a potential threat. Salt water penetrates into the river system during flood tide. The extent of these tides is likely to increase with rise of sea level, beach erosion and mangrove destruction, which all are phenomena on the increase (Narayan, 2006). Human presence and especially boat traffic, is thought to be associated with a lower amount of sightings. However Giant Otters can still be seen in relatively busier areas (such as in the Rupununi River, sometimes even found on boat landings). Predicted future distribution trends in response to current and anticipated threats Changes in distribution of the Giant River Otter in relation to human threats have not been documented. However, it can be assumed that mining pollution may strongly impact on the populations distribution. Gold mining activities are more important in the northern part of the country (see maps 1 and 2 following). A shift towards the southern rivers of the country is hence possible. In any case, populations of the northern parts of the country are likely to decrease and suffer from mercury pollution, whose effects will only be revealed on the long term.

4 Figure 2: Mineral property status map of Guyana, 2003 and Provisional geochemical atlas of Guyana (displaying element Au, gold), Both maps prepared by The Guyana geology and mines commission. Reconnaissance, prospecting, and mining areas are mostly found in the North of the country; Gold is also present in the North West part of Guyana. As Giant Otters occupy the wetlands differently according to wet or dry seasons, changes in climate may affect their distribution. Guyana has undergone unusually long periods of La Nina, which brings with her flood conditions. Usage of the flooded forest as habitat is hence extended too; the consequences of this are currently unknown. Knowledge of the species Giant otters were surveyed in 2002 in the Rupununi and Iwokrama Forest, which lead to the production of maps with dens location and approximate otter densities. Another survey took place in 2009 along the Essequibo, Burro-Burro and Siparuni Rivers and otter sightings are still recorded to this day. Karanambu is known for the high amount of otters present especially on the Rupununi River, a tributary of the Essequibo. A study was conducted in in order to collate more quantitative and qualitative information on the Giant Otters near Karanambu (Duplaix, 2004). A survey was carried by a volunteer biologist in 2010 at Karanambu (25 jan-7 feb) following a wildlife club training workshop. There, Diane McTurk has been rehabilitating orphaned otters for over 30 years and the place is seen as expert in otters ecology and behaviour (McTurk and Spelman, 2005). Little formal research has however been conducted on the site. Legal status The giant otter is listed in Appendix I of the Convention on International Trade in Endangered Species (CITES), as Endangered under the United States Endangered Species Act and as Endangered under the IUCN Red List. In Guyana, the giant otter is listed on Schedule IV of the species Protection Regulations (1999), made pursuant to the Environmental Protection Act (1996). The schedule IV lists species requiring protection in Guyana, indicating otters are subjects to the provisions of Species Protection Regulations (1999),

5 which is the legislation regulating wildlife trade. Other measures to protect giant otters in Guyana are not clearly defined (A. Sankar, Head of Wildlife Division, Guyana, 2012, personal communication). Past, current and planned conservation initiatives Training and workshop In 2010, a workshop was organized at Karanambu. Young wildlife club members were selected for this training. The aim was to use a citizen science method, where visitors and tourist participate in the monitoring activity and submit photos used to identify and monitor individuals (S. James, 2012, personal communication). By uploading the photos to Google Earth, a data base would be created, containing locations of sightings of identifiable individuals. Knowledge dissemination, education and awareness-raising A workshop realised in 1998 by Iwokrama lead to the creation of a brochure containing detailed information regarding Community-based wildlife management in the North Rupununi, which was made accessible to local communities and generated a higher wildlife conservation awareness amongst the North Rupununi inhabitants, including for the Giant Otters (NRDDB and Iwokrama, 2000, unpublished). In 2010, the Giant Otters workshop help at Karanambu trained wildlife club members whose aim was also to disseminate knowledge amongst their community, discuss issues, find solutions to challenges and present the outcomes related to the study. Management and protected areas Protected areas in Guyana where the Giant Otters occur are: Iwokrama Wilderness Preserve (1997, 360,000 ha in total, half being a preserve and the other half an area where use of resource is made sustainably; Giant Otters are part of the Iwokrama Centre s Forest Impact Monitoring program), Kaieteur National Park (1929, 242 square miles), the Kanuku Mountains (2011) and the Konashen district (2004, Community Owned Conservation Area, 4,000km 2 ). Recommendations for future effort Research The species requires extensive monitoring. Community-based surveys are believed to be the best way to record reliable counts and geographical distribution as local communities are able to identify otters individually. Research is required regarding the precise distribution of the species, the population dynamics and the interactions with their natural habitats. Consistent surveys are required to run comparative studies and quantify the evolution of population size and distribution scientifically. Information collected by every community need to be gathered into a single database in order to allow for a global understanding of trends, generate comprehensive maps and design relevant conservation plans. In order to design relevant management of the populations, the habitat use, especially the contrast occurring during rainy and dry seasons, requires to be investigated in order to understand the patterns of habitat use along the year. Similar observations in Ecuador recommend the use of satellite or radiotransmitters (Utreras et al., 2005). The estimation of home range is also to be determined. The recent increase in interest of communities for ecotourism is also to be addressed. The ecological requirements of the species are hence to be better understood before designing a relevant population management plan. In the meantime, impacts of ecotourism are not described, and a precautionary approach should be preferred.

6 Training The combination of information rigorously collected by the communities and their analysis through ecological modelling, would lead to a deep understanding of the local Giant Otter populations. Training should be dispensed to local communities regarding efficient survey methods and data storing. The standardisation of the methodology to all concerned communities allows generating a highly reliable dataset and accentuates collective conservation mind through the communities. Education and awareness Conservation awareness was acquired by the local communities through local campaigns. Such environmental education is essential to the health of local populations of Giant Otters and should be continuously promoted to the communities. Wildlife clubs, workshops and wildlife festivals are efficient means to convey the message of conservation within communities. Bibliography Barnett A., Shapley R., Lehman S., Henry E. And Benjamin P Records of the Giant Otter Pteronura brasiliensis, from Guyana, IUCN Otter Specialist Group Bulletin, 17 (2): Bicknell J., Snyder A., Kemp J and Lim B Monitoring of vertebrates by Operation Wallacea in the Iwokrama forest and Surama forests, Guyana, Operation Wallacea Research report, Carter S.K. and Rosas F.D.W Biology and conservation of the Giant Otter Pteronura brasiliensis. Mammal Review, 27 (1): Duplaix N Guyana Giant Otter Project, research results, Oceanic Society Expeditions, 44pages. Hays P. And Vieira R., WWF Guianas Mercury contamination, a legacy to handicap a generation, WWF Guianas regional program office technical paper, Series 2. Available online at: < downloaded on February 24 th James S Final report Wildlife club Giant Otter monitoring in Guyana, Chicago Board of Trade Endangered Species Fund, report prepared by S. James, Community Education and Awareness Manager, Iwokrama International Centre, unpublished. Narayan K., Carribean institute for meteorology and hydrology, Climate change impacts on water resources in Guyana. 5 th World FRIEND Conference, La Habana, Cuba, North Rupununi District Development Board, NRDDB, Local Ecological knowledge of some of the large mammals in the North Rupununi and Iwokrama Forest, unpublished. North Rupununi District Development Board and Iwokrama International Centre for Rainforest Conservation and Development, Community-based wildlife management in the North Rupununi. NRDDB, J. Forte, N. Janki, G. Watkins, eds McTurk D. and Spelman L Hand-rearing and rehabilitation of orphaned wild Giant Otters, Pteronura brasiliensis, on the Rupununi River, Guyana, South America. Zoo Biology, 24: Pickles R., McCann N and Holland A A biodiversity assessment of the Rewa Head, Guyana, July ZSL conservation Report No. 10. The Zoological Society of London, London. Sanderson J.G., E. Alexander, V. Antone and C. Yukuma. Non-volant mammals of the Konashen COCA, Southern Guyana. In: J.R. Montambault and O. Missa, eds A rapid biological assessment of the Konashen community owned conservation area, Southern Guyana, RAP Conservation International, Bulletin of Biological Assessment, 26 (Chapter 5): Sanderson J.G. and Ignacio L. Non-volant mammals survey results from the Eastern Kanuku Mountains, Lower Kwitaro River, Guyana. In: L.E. Alonso, J. McCullough, P. Naskrecki, E. Alexander and H.E. Wright, eds A rapid biological assessment of the Konashen community owned conservation area,

7 Southern Guyana, RAP Conservation International, Bulletin of Biological Assessment, 51 (Chapter 8): The Guyana geology and mines commission. Mineral property status map of Guyana, March Available online at : < >. Downloaded on February 26 th The Guyana geology and mines commission. Provisional geochemical atlas of Guyana (Au), Available online at: < Downloaded on February 26 th Utreras V.B., Suarez A.R., Zapata-Rios G., Lasso G. and Pinos L Dry and rainy season estimations of Giant Otter, Pteronura brasiliensis, home rane in the Yasuni National Park, Ecuador. Latin American Journal of Aquatic Mammals, 4(2): Hydromet, Ministry of agriculture hydrometeorological service, Guyana. Available online at: < Consulted on February 26 th 2012.