|Scientific Name:||Trochulus biconicus|
|Species Authority:||(Eder, 1917)|
Trichia biconica Eder, 1917
Trochulus biconica (Eder, 1917)
|Taxonomic Notes:||A taxonomic review of the genus Trochulus spp. is underway by Gerhard Falkner and Ted von Proschwitz.|
|Red List Category & Criteria:||Endangered B1ab(ii,iii,iv) ver 3.1|
|Reviewer/s:||Neubert, E., Bilz, M. & Ward, J.|
The species meets the area requirements under criterion B for Endangered due to it having an extent of occurrence of less than 5,000 km2. There is evidence of ongoing habitat loss and degradation as well as population loss through the impacts of climatic change, with some populations below 2,000 m altitude being lost. Therefore, it is assessed as Endangered (EN) B1ab(ii,iii,iv).
|Range Description:||The species has a very restricted distribution with an extent of occurrence of less than 5,000 km2, and is only found in the Central Alps in Switzerland. It is known only from Kantone Nidwalden, Obwalden and Uri. There are 130 very small localities known, all between 2,100 and 2,575 m asl.|
|Range Map:||Click here to open the map viewer and explore range.|
The density is low and the population trend is decreasing. Some populations of altitudes between 1,800 m to 2,000 m asl. no longer exist.
|Habitat and Ecology:||This species lives on alpine meadows underneath carbonate rocks which become free from snow relatively early.|
The populations are threatened by the climate change (Baggot 2010, unpublished). Some populations between 1800 and 2000 m no longer exist and there is a trend of the species' range reducing below 2,000 m. As a result of climate change the habitats of the populations are becoming more unstable as the cycles of freezing and thawing increase and stones are loosened with a greater risk from avalanches.
The Swiss military used the locus typicus for shooting target practice which may have had a negative impact on the species, but this stopped some years ago.
|Conservation Actions:||The species is listed on the Swiss Red List as Vulnerable (VU) (Turner et al. 1998). The known sub-populations require monitoring to see if the apparent trend in the decline of sites of lower altitudes continues.|
|Citation:||Rüetschi, J. 2011. Trochulus biconicus. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 19 June 2013.|
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