Friday 17 May
Delany's swamp mouse (Delanymys brooksi)

Top facts
- Delany's swamp mouse is one of the world's smallest rodents, measuring just 5 to 6 cm long.
- Delany's swamp mouse is a very active climber, using its grasping tail for balance and support.
Delany's swamp mouse fact file
- Description
- Biology
- Range
- Habitat
- Status
- Threats
- Conservation
- Find out more
- Glossary
- References
- Print factsheet
Delany's swamp mouse description
| Kingdom | Animalia |
| Phylum | Chordata |
| Class | Mammalia |
| Order | Rodentia |
| Family | Nesomyidae |
| Genus | Delanymys (1) |
The only member of its genus, Delany’s swamp mouse (Delanymys brooksi) is the smallest member of the Nesomyidae family, and one of the smallest rodents in the world (3) (4) (5).
Delany’s swamp mouse is a very small climbing mouse with an extremely long tail and characteristically long hind feet (3). The pelage of this species is long and is typically slate-grey at the base of the hairs, and brown with a reddish-orange tinge towards the tips. The underside of Delany’s swamp mouse is pale yellow-brown to buff (2).
This species has long black guard hairs, which give it a darker colouration (3). The eyes of Delany’s swamp mouse are surrounded by short black hairs and there is a black patch on the nose, while a distinctive patch of pure white hairs is present on the throat (2).
Delany’s swamp mouse has large, round ears and its tail is longer than the combined head-and-body length. The tail is thin, almost hairless, and has scales forming ring-like patterns along its length (2) (3). The male Delany’s swamp mouse is slightly smaller than the female, and the young have brighter, hazel-coloured fur (3).
- Also known as
- Delany's mouse. Top
-
Kahuzi-Biega National Park (KBNP):
http://kahuzibiega.wordpress.com/ - Genus
- A category used in taxonomy, which is below ‘family’ and above ‘species’. A genus tends to contain species that have characteristics in common. The genus forms the first part of a ‘binomial’ Latin species name; the second part is the specific name.
- Guard hairs
- In some mammals, long, coarse hairs that protect the softer layer of fur below.
- Montane forest
- Forest occurring in mountains.
- Nocturnal
- Active at night.
- Omnivore
- An organism that feeds on both plants and animals.
- Prehensile
- Capable of grasping.
- Subfamily
- A taxonomic category below a family but above a genus; a sub-division of a family, containing genera which are different enough to warrant a minor separation from the rest of the family.
- Tubercle
- A small, rounded, wart-like bump on the skin or on a bone.
-
IUCN Red List (November, 2011)
http://www.iucnredlist.org/ - Nowak, R.M. (1999) Walker's Mammals of the World. The Johns Hopkins University Press, Baltimore.
- Dieterlen, F. (2010) Pers. comm.
- Vaughan, T.A., Ryan, J.M. and Czaplewski, N.J. (2011) Mammology. James and Bartlett Publishers, LLC, Sudbury.
- Britannica Educational Publishing (2011) Rats, Bats, and Xenarthrans. Britannica Educational Publishing, New York.
- view the contents of, and Material on, the website;
- download and retain copies of the Material on their personal systems in digital form in low resolution for their own personal use;
- teachers, lecturers and students may incorporate the Material in their educational material (including, but not limited to, their lesson plans, presentations, worksheets and projects) in hard copy and digital format for use within a registered educational establishment, provided that the integrity of the Material is maintained and that copyright ownership and authorship is appropriately acknowledged by the End User.
Delany's swamp mouse biology
The nocturnal Delany’s swamp mouse is extremely well adapted for climbing on grass and plant stems. Its feet are highly specialised, with long, spreading digits and numerous small, prominent tubercles on the palms and fingers which enable grasping and prevent slipping. The long, prehensile tail of Delany’s swamp mouse is used to provide balance and can even be curled around stems for additional support (1) (3). Seeds make up the majority of this small rodent's diet (2) (4).
Little is known about the reproductive behaviour of Delany’s swamp mouse, although two pregnant females have been recorded with three embryos each, and one nest with four blind young has been found. This species constructs a small, round grass nest with two entrances, usually off the ground in a bush or other such vegetation (2).
TopDelany's swamp mouse range
Delany’s swamp mouse is native to the Albertine Rift Valley in southwest Uganda, western Rwanda, Burundi and the extreme eastern Democratic Republic of the Congo (1).
TopDelany's swamp mouse habitat
Delany’s swamp mouse is largely confined to high-altitude marshes within bamboo or montane forests, at elevations of 1,700 to 2,400 metres or higher (1). A few individuals have been found in non-marshy habitats, such as dense, grassy vegetation (3).
TopDelany's swamp mouse status
Delany's swamp mouse is classified as Vulnerable (VU) on the IUCN Red List (1).
TopDelany's swamp mouse threats
The small geographic range and fragmented distribution of Delany’s swamp mouse make it very vulnerable to continuing decline. Habitat destruction, largely due to agriculture and the high human population density of the region, is one of the greatest reasons for this species’ decreasing population size (1).
TopDelany's swamp mouse conservation
No specific measures are currently in place to conserve Delany’s swamp mouse, despite it being the only surviving member of its subfamily, Delanymyinae (4). Much of its highland habitat is in the Kahuzi-Biega National Park in the Democratic Republic of the Congo. However, the lowlands remain severely threatened (1).
The population numbers of Delany’s swamp mouse need to be researched and monitored. Studies into the range, biology, ecology, habitat status and threats to this species are also needed in order to inform any future potential conservation measures (1).
TopFind out more
Find out more about Kahuzi-Biega National Park:
Authentication
This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk
Glossary
References
More »Related species
Close
Image credit
© Dr. Fritz Dieterlen
Dr. Fritz Dieterlen
1969-1999 Head of the Mammal Section. Retired in 1994, then working as Research Associate and Honorary Member up to present
Staatliches Museum für Naturkunde Stuttgart, Rosenstein 1
Stuttgart, D- 70191
Germany
Tel: 07158 / 3796
fdieterlen@t-online.de
Close
Link to this photo
Embed this ARKive thumbnail link by copying and pasting the code below.
Terms of Use - The displayed thumbnail may be used as a link from your website to ARKive's online content for private, scientific, conservation or educational purposes only. It may NOT be used within Apps.
Read more about
Close
MyARKive
MyARKive offers the scrapbook feature to signed-up members, allowing you to organize your favourite ARKive images and videos and share them with friends.
Close
Terms and Conditions of Use of Materials
Copyright in this website and materials contained on this website (Material) belongs to Wildscreen or its licensors.
Visitors to this website (End Users) are entitled to:
End Users shall not copy or otherwise extract, alter or manipulate Material other than as permitted in these Terms and Conditions of Use of Materials.
Additional use of flagged material
Green flagged material 
Certain Material on this website (Licence 4 Material) displays a green flag next to the Material and is available for not-for-profit conservation or educational use. This material may be used by End Users, who are individuals or organisations that are in our opinion not-for-profit, for their not-for-profit conservation or not-for-profit educational purposes. Low resolution, watermarked images may be copied from this website by such End Users for such purposes. If you require high resolution or non-watermarked versions of the Material, please contact Wildscreen with details of your proposed use.
Creative commons material
Certain Material on this website has been licensed to Wildscreen under a Creative Commons Licence. These images are clearly marked with the Creative Commons buttons and may be used by End Users only in the way allowed by the specific Creative Commons Licence under which they have been submitted. Please see http://creativecommons.org for details.
Any other use
Please contact the copyright owners directly (copyright and contact details are shown for each media item) to negotiate terms and conditions for any use of Material other than those expressly permitted above. Please note that many of the contributors to ARKive are commercial operators and may request a fee for such use.
Save as permitted above, no person or organisation is permitted to incorporate any copyright material from this website into any other work or publication in any format (this includes but is not limited to: websites, Apps, CDs, DVDs, intranets, extranets, signage, digital communications or on printed materials for external or other distribution). Use of the Material for promotional, administrative or for-profit purposes is not permitted.













