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45. Handley’s Slender Mouse Opossum

Marmosops handleyi


A delicately built mouse opossum, with a prehensile tail and no pouch.

A delicately built mouse opossum, with a prehensile tail and no pouch. Virtually nothing is known about the ecology of this species. It is thought to be nocturnal, arboreal and eat fruit and insects, like other 14 mouse opossums of the genus Marmosops. It is only known from one small 48km² location in central Colombia, whose surrounding environment has been converted to agriculture and pastures.

  • Order: Didelphimorphia
  • Family: Didelphidae
  • Population: Unknown
  • Trend: decreasing
  • Size: 104-122mm
  • Weight: 21-85g

EDGE Score

EDGE Score: 5.46 (?)
ED Score: 13.19 (?)
GE / IUCN Red List (?)
Not Evaluated Data Deficient Least Concern Near Threatened Vulnerable Endangered Critically Endangered Extinct in the Wild Extinct


Handley’s slender mouse opossum inhabits 3 known sites within central Columbia, two in Yaramul and one at Amalfi. All 3 sites are found within a 48km long range.

Habitat and Ecology

This species nocturnal and arboreal, inhabiting lowland or montane tropical rainforest. They feed on insects and fruit, they are thought to be reproductively active during Colombia’s rainy season (Sept-Nov) and have a weaning period that lasts until the following dry season (Dec-Feb).

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Conservation Actions

For each key category of conservation action, we calculated a conservation attention score based on expert information. In this graph, a higher score means the action is being carried out more intensively over more of the species range. The colour shows how important each action is considered to be for the conservation of this species.

Engaging stakeholders
Addressing threats
Status of knowledge
Management plan
Capacity building
Behaviour change
Awareness raising
  Score: 100 means the activity occurs at high level across more than 75% of the species range
Very Low

Overall Conservation Attention

We combined all of the expert information on conservation actions to calculate an overall conservation attention score for this species. Please help us to reach our goal of establishing dedicated conservation attention at “High” levels for all EDGE species.

Very Low Low Medium High

More information

Recent studies have grouped all possible conservation activities for any species into nine key categories (Washington et. al 2015). For each action, we asked experts for each species to assess the extent to which that action is being carried out and how much of the species’ range that action occurs in. For each action we used these two pieces of information to calculate the conservation attention score per action. A score of 100 means that the action is being carried out to a high level across at least 75% of the species range. We then combined the scores for all actions into an overall conservation attention score for the species. The experts also judged how important each category was to the conservation of that particular species.

This wordcloud illustrates the threats facing this species. The size of each word indicates the extent of a species range that is affected by that threat (larger size means a greater area is affected). The colour of the word indicates how much that threat impacts the species (darker shades of red mean the threat is more severe).

Urban development Tourism Habitat change Droughts Extreme temperatures Crops Wood plantations Livestock Mining Roads/Rail Utility lines Flightpaths Hunting Gathering Logging Recreation Wars Work Fire Ecosystem changes Invasive species Wastewater Agriculture Garbage Air pollution

Threat wordcloud key:

Small area affected
Large area affected
Least severe
Most severe
Severity unknown
Source: EDGE

Vision (30-50 years)

Population and habitat of Handley’s Slender Mouse Opossum protected, restored or enhanced through coordinated efforts at international, national and local levels, guided by sound science and effective management.

Goal (5-10 years)

To conduct research to refine the conservation status of the Handley’s Slender Mouse Opossum in Antioquia and provide training for the Conservation Plan and with Involvement of Stakeholders


Conduct systematic Research & Monitoring on Handley's Slender Mouse Opossum population status, range, habitat use, ecology, ecological requirements and genetic viability. Critical
Habitat recovery Critical
Stimulate landowners to create and manage Private Reserves for Opossum Critical
Key corridors identified and managed High
Causes of habitat loss mitigated High
Promote the integration between enforcement agencies, institutions and stakeholders, to improve the enforcement of environmental laws in Handley's Slender Mouse Opossum Medium

Daira Ximena Chavarro

  • Project name: Conservation of Handley's slender mouse opossum: ecological monitoring and community outreach
  • Project site: Valdivia and Yarumal, Colombia
  • Active: 2012 - 2014
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