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99. Nelson’s Small Eared Shrew

Cryptotis nelsoni


Nelson’s Small Eared Shrew is a medium-sized shrew and is thought to be endemic to the forested slopes of a small volcano in southern Mexico.

The volcano upon which the tiny shrew lives erupted in 1793, destroying all the vegetation around the crater. Despite this eruption, the shrew managed to survive, and the volcano is now extinct. Nelson’s small eared shrew was discovered in 1894, but not seen again for more than a century, leading researchers to fear it had gone extinct. However, in 2003, two researchers set out to search for the species in the same region from which it was first discovered. Their expedition met with success, and they found three individuals. Although good news for the species, the researchers discovered that the species’ tiny range is under pressure from human activities, including logging, cattle grazing, induced fires and agriculture. Urgent conservation action is needed if this Critically Endangered shrew is to survive. Shrews are a highly successful group of insectivores, comprising the third most speciose (rich in species) mammal family (Soricidae). They occur throughout most of the world, with the exception of Australasia and much of South America. They are often portrayed as “primitive” animals; indeed, the earliest mammals are often portrayed as shrew-like.

  • Order: Eulipotyphla
  • Family: Soricidae
  • Population: Unknown
  • Trend: unknown
  • Size: 5.5-10cm

EDGE Score

EDGE Score: 5.13 (?)
ED Score: 9.59 (?)
GE / IUCN Red List (?)
Not Evaluated Data Deficient Least Concern Near Threatened Vulnerable Endangered Critically Endangered Extinct in the Wild Extinct


They are Endemic to Mexico, only having been found in their type locality on the western slope of the extinct San Martín Tuxtla volcano in Veracruz, Mexico, and in 2003 on the southern face of the volcano. It may be that the shrew occurs in suitable habitats throughout the Sierra de Santa Martha.

Habitat and Ecology

This species inhabit evergreen tropical forest and areas covered by layers of volcanic sand and ashes. In general, shrews have a high metabolic rate and consequently a voracious appetite meaning they must eat very frequently, and so are active throughout the day and night. Nelson’s small-eared shrew is believed to feed exclusively on insects.

Find out more

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 Crops Livestock Logging

Threat wordcloud key:

Small area affected
Large area affected
Least severe
Most severe
Severity unknown
Source: The IUCN List of Threatened Species. Version 2017.1.
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