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Limnogale mergulus
– Vulnerable
Taxonomy
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Kingdom:
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ANIMALIA
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Phylum:
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CHORDATA
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Class:
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MAMMALIA
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Order:
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AFROSORICIDA
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Family:
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TENRECIDAE
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Scientific Name:
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Limnogale mergulus
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Species Authority:
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Major, 1896
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Common Name/s:
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Assessment Information
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Red List Category & Criteria:
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VU B2ab(ii,iii) ver 3.1 (2001)
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Year Assessed:
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2006
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Assessor/s:
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Afrotheria Specialist Group (Tenrec Section), Olson, L. & Goodman, S.
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Evaluator/s:
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Rathbun, G. (Afrotheria Red List Authority) & Sechrest, W. (Global Mammal Assessment)
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Justification:
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This species is poorly known, with localities across a relatively wide area, although not many appropriate surveys have been carried out. Since this species is restricted to streams within natural forests, there is estimated to have less than 2,000 km² habitat remaining. These streams are undergoing a decline in habitat quality, especially from siltation, and the species' area of occupancy is declining. Further research is needed to determine how restricted this species is within the forested stream habitats of its range, and certainly could elevate its threat status. The species is listed as Vulnerable B2ab(ii,iii).
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History:
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| 1988 | - | Vulnerable (IUCN Conservation Monitoring Centre 1988) |
| 1990 | - | Indeterminate (IUCN 1990) |
| 1994 | - | Indeterminate (Groombridge 1994) |
| 1996 | - | Endangered (Baillie and Groombridge 1996) |
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Geographic Range
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Range Description:
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This species is endemic to Madagascar. It occurs in the eastern humid forest and central highlands. This species has only been recorded from a few localities in Madagascar (10 sites listed in Benstead and Olson 2000), including the Antsanpandrano Forestry Station on the Ankarata Massif, a site 15 km north of Antanifotsy village (Andringitra), a site 10 km north of Andekaleka, one specimen was caught in an eel trap at Ranomafana Est, 60 km east of Fianarantsoa; and a site 35 km south of Antsirabe. Its amphibious lifestyle is an impediment to the study of its distribution, which is poorly known. The altitudinal range is 450–2,000 m. There have not been many appropriate surveys in the intervening areas between the known localities, though it is likely present in appropriate habitat.
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Countries:
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Native:
Madagascar
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Population
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Population:
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This species is only known from a few sites. Only two sites (Antsanpandrano and Ramonafana) have had repeated survey work.
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Population Trend:
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Habitat and Ecology
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Habitat and Ecology:
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This species is semi-aquatic carnivore, occurring along streams and rivers. The main habitat requirements are permanent, clean and fast flowing water. This species is thought to feed on freshwater crayfish, aquatic insect larvae and small crustaceans. However, it has once been found in streams within a pine plantations (which potentially keep siltation down similar to native vegetation), although this does not seem to be the case in other areas within its range (Goodman, pers. comm).
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System:
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Freshwater
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List of Habitats:
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| 1.6 | Forest - Subtropical/Tropical Moist Lowland |
| 5.1 | Wetlands (inland) - Permanent Rivers/Streams/Creeks (includes waterfalls) |
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Threats
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Threats:
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This species apparently requires clean and fast flowing water and is therefore vulnerable to siltation and soil erosion caused by deforestation. Agricultural expansion is fragmenting the upland forests, thereby isolating fast-flowing riverine habitat. Previously, collection and removal of the plant Aponogeton, which L. mergulus is closely associated with, was thought to cause an adverse reaction from the population (Nowak 1999), however this has since been refuted (Benstead and Olson 2000). Accidental capture in fish traps has also been recorded.
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List of Threats:
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| 1.1.1.1 | Habitat Loss/Degradation - Agriculture - Crops - Shifting Agriculture (ongoing) |
| 1.3.3.1 | Habitat Loss/Degradation - Extraction - Wood - Small-scale subsistence (ongoing) |
| 1.3.3.2 | Habitat Loss/Degradation - Extraction - Wood - Selective logging (ongoing) |
| 4.1.1.3 | Accidental mortality - Bycatch - Fisheries-related - Entanglement (ongoing) |
| 6.3.7 | Pollution (affecting habitat and/or species) - Water pollution - Sediment (ongoing) |
| 9.1 | Intrinsic factors - Limited dispersal (ongoing) |
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Conservation Actions
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Conservation Actions:
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This species is only known from two protected areas, Ranomafana National Park and the Andringitra National Park. The vulnerability of benthic prey communities to sedimentation implies that prevention of erosion and sedimentation is of paramount importance for conservation of this species. New and existing sites for the species must be protected from the effects of sedimentation wherever possible, either by inclusion of forested catchments in the protected areas network or by other means (e.g., effective terracing of agricultural fields and maintenance of vegetated riparian zones) (Benstead et al. 2001).
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List of Conservation Actions:
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| 3.2 | Research actions - Population numbers and range (in place, needed) |
| 3.3 | Research actions - Biology and Ecology (in place, needed) |
| 3.4 | Research actions - Habitat status (in place, needed) |
| 3.5 | Research actions - Threats (in place, needed) |
| 3.8 | Research actions - Conservation measures (needed) |
| 3.9 | Research actions - Trends/Monitoring (needed) |
| 4.1 | Habitat and site-based actions - Maintenance/Conservation (needed) |
| 4.4.2 | Habitat and site-based actions - Protected areas - Establishment (in place, needed) |
| 4.4.3 | Habitat and site-based actions - Protected areas - Management (in place, needed) |
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Bibliography
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Bibliography:
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Afrotheria Specialist Group. For more information, see the Specialist Group website Baillie, J. and Groombridge, B. (compilers and editors) 1996. 1996 IUCN Red List of Threatened Animals. IUCN, Gland, Switzerland. Creighton, B.K. pers. comm. Gould, E. and Eisenberg, J.F. 1966. Notes on the biology of the Tenrecidae. Journal of Mammalogy 47: 660-686. Groombridge, B. (ed.) 1994. 1994 IUCN Red List of Threatened Animals. IUCN, Gland, Switzerland. IUCN Conservation Monitoring Centre. 1988. 1988 IUCN Red List of Threatened Animals. IUCN, Gland, Switzerland and Cambridge, UK. IUCN. 1990. 1990 IUCN Red List of Threatened Animals. IUCN, Gland, Switzerland and Cambridge, UK. Malzy, P. 1965. Un mammifère aquatique de Madagascar le Limnogale. Mammalia 29: 399-411. Nicoll, M.E. and Rathbun, G.B. (compilers) 1990. African Insectivora and Elephant-Shrews: An Action Plan for their Conservation. IUCN/SSC Insectivore, Tree-Shrew and Elephant-Shrew Specialist Group. IUCN, Gland, Switzerland. Nicoll, M.E. and Stephenson, P.J. pers. obs. Nowak, R.M. (ed.) 1999. Walkers Mammals of the World. Sixth edition. The Johns Hopkins University Press, Baltimore and London. Stone, R.D. and Gould, E. pers. comm. Wilson, D.E. and Reeder, D.M. (eds). 1993. Mammal Species of the World: a taxonomic and geographic reference. Second edition. Smithsonian Institution Press, Washington and London.
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