IUCN SSC Mid-Atlantic Island Invertebrates Specialist Group


BackMedon varamontis Assing, 2013

Medon varamontis Assing, 2013

Rove beetle (English)

  • Kingdom: Animalia
  • Phylum: Arthropoda
  • Class: Insecta
  • Order: Coleoptera
  • Family: Staphylinidae
CR Critically Endangered
IUCN Red List Status:

Countries of Occurrence:
Portugal - Azores


Danielczak, A.


Facilitators / Compilers/s:

Assessment Rationale:

Medon varamontis is an endemic species from S. Miguel (Azores, Portugal) (Borges et al. 2010), known from Natural Forest Reserve of Pico da Vara. It has a very small extent of occurrence (EOO = 4 km²) and area of occupancy (AOO = 4 km²). There is a continuing decline in the EOO, AOO, extent and quality of habitat  as a result of major land-use changes in the last 50 years. The species occurs only at one location. One of the most important ongoing threat to this species is the spread of invasive plants, but the managment of Cryptomeria japonica plantations can also be a major problem. Therefore, we suggest as future measures of conservation: (1) regular monitoring of the species; and (2) recover of natural bogs and grasslands. Based upon the small geographic range of the species with only one location and continuing decline of its habitat area and quality, it is assessed as Critically Endangered.

Geographic Range:

Medon varamontis is a single island endemic species from S. Miguel (Azores, Portugal) (Borges et al. 2010), known from Natural Forest Reserve of Pico da Vara. The extent of occurrence (EOO) is 4 km² and the maximum estimated area of occupancy (AOO) is 4 km².

Portugal - Azores
Extent of Occurrence (EOO):
4 (km2)
Area of Occupancy (AOO):
4 (km2)
Elevation Lower Limit:
1000 (m)
Elevation Upper Limit:
1200 (m)
Biogeographic Realms:
Endemic Azores


The species is particularly abundant and only known from a single subpopulation in a high elevation area in S. Miguel island. There is an inferred declining in the population due to invasive plant species spreading (e.g. Hedychium gardnerianum; Clectra arborea), that are changing the structure of the forest and the cover of bryophytes and ferns in the soil decreasing the quality of the habitat with impacts on the species.

Habitat and Ecology

This species occurs in one single native natural grassland and bog patch (dominated by Sphagnum spp.) located at high altitude with also the scattered presence of the Azorean cedar (Juniperus brevifolia), in S. Miguel island (Pico da Vara). This species has an altitudinal range between 1000 and 1200 m. It is a nocturnal predator that lives in the soil associated with grass roots and litter.

Major Threat(s):

In the past, the species has probably strongly declined due to changes in habitat size and quality (Triantis et al. 2010), mostly the creation of plantations of Cryptomeria japonica and pastures. The management of Cryptomeria japonica  is still a problem. One of the most important ongoing threats to this species is the spread of invasive plants, namely Hedychium gardnerianum and Clethra arborea that are changing the habitat structure, namely decreasing the cover of bryophytes and ferns in the soil and promoting the spread of other plants. Based on Ferreira et al. 2016 the habitat will further decline as a consequence of climate change (increasing number of droughts and habitat shifting & alteration).

Conservation Actions

The species is not protected by regional law. Its habitat is in a regionally protected area (Natural Park of S. Miguel). Further spread of invasive plants needs to be stopped in order to avoid any future declines of the species. Degraded habitats should be restored and a strategy needs to be developed to address the future threat by climate change. A habitat management plan is needed and anticipated to be developed during the coming years. Formal education and awareness is needed to allow future investments in restored habitats invaded by invasive plants. Further research is needed into its ecology and life history in order to find more extant specimens in additional areas around Pico da Vara (S. Miguel) and obtain information on population size, distribution and trends. It is also necessary a monitoring plan for the invertebrate community in the habitat in order to contribute to perform a species potential recovery plan. A monitoring every ten years using the BALA protocol will inform about habitat quality (see e.g. Gaspar et al. 2011).