Guayaquil squirrel

The Guayaquil squirrel (Sciurus stramineus) is a tree squirrel endemic to Ecuador and Peru. It is a robust squirrel with a head-and-body length of 18 to 32 cm (7 to 13 in) and a similar length tail. The colour is variable; in Peru, a pale morph is more common, while in Ecuador, most individuals have darker grey fur on the forequarters, dull orange hindquarters. A melanistic morph is sometimes seen. It lives largely in trees and is diurnal, feeding on seeds, flowers, and other plant material, fungi and some insects. These squirrels are also found in urban areas, living in close proximity to humans, and may be vectors for leptospirosis and Chagas disease.^[3] This squirrel faces no particular threats, has a wide range and is relatively common, and the International Union for Conservation of Nature has rated it as being of "least concern".

Guayaquil squirrel
Conservation status
Least Concern  (IUCN 3.1)[1]
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Rodentia
Family:	Sciuridae
Genus:	Sciurus
Species:	S. stramineus
Binomial name
Sciurus stramineus Eydoux & Souleyet, 1841[2]
Guayaquil Squirrel's range

Description

Guayaquil squirrels are relatively heavily built squirrels, weighing around 470 grams (17 oz). They measure from 18 to 32 centimetres (7.1 to 12.6 in) in head-body length, and have a long tail, measuring 25 to 33 centimetres (9.8 to 13.0 in), in proportion to their body. The scientific name means "straw-coloured squirrel", but, in fact, their colour is highly variable. Past attempts to identify different subspecies on the basis of coat colour are, however, no longer recognised, since there was no clear distinction between them.^[4]

There are at least two morphs. The paler morph, which is more common in Peru, has pale grey fur grizzled with white over most of the body, a buff rump, a white or pale yellow patch on the back of the neck, and grey underparts. The darker morph, which is more common in the Ecuadorian lowlands, has grey fur on the forequarters, dull orange hindquarters, grizzled black and white shoulders, and grey underparts. However, even these two morphs are highly variable, with the patches on the shoulders or rump being absent, or the underparts being tawny or even reddish, in some individuals. A third, rarer, melanistic morph has also been reported, with black fur covering almost the entire body, except for a white patch on the collar, and occasional white spots on the back.^[4]

All morphs have black ears and a slender grey tail. The latter feature can be used to distinguish this species from the only other Ecuadorian tree-squirrel, the red-tailed squirrel.^[4]

Distribution and habitat

Guayaquil squirrels are found in the wild only in southwestern Ecuador and northwestern Peru. A small population has also been introduced to parks in Lima.^[5] They inhabit a range of forest types, from dry to humid, along the western slopes of the Andes between 300 and 2,000 metres (980 and 6,560 ft) in elevation. They have also been reported from coffee plantations.^[4] There are no currently recognised subspecies.

Behaviour and biology

Like other squirrels, the Guayaquil squirrel feeds primarily on seeds, although it also eats flowers, mushrooms, and other plant material, and some insects. They are adaptable, and able to survive in cities,^[5] and also breed well in captivity. They are diurnal and arboreal, spending most of their lives in the trees.^[4] They construct nests about 30 centimetres (12 in) across from woven sticks, in tree branches over 5 metres (16 ft) above the ground.^[6] They live for up to seven years in captivity.^[4]

References

1. Duckworth, J. W. & Koprowski, J. (2008). "Sciurus stramineus". IUCN Red List of Threatened Species. 2008. Retrieved 6 January 2009.{{cite iucn}}: old-form url (help)
2. Wilson, D. E.; Reeder, D. M., eds. (2005). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. ISBN 978-0-8018-8221-0. OCLC 62265494.
3. Grijalva, M.J.; Villacis, A.G. (2009). "Presence of Rhodnius ecuadoriensis in sylvatic habitats in the southern highlands (Loja Province) of Ecuador". Journal of Medical Entomology. 46 (3): 708–711. doi:10.1603/033.046.0339. PMID 19496445.
4. Merrick, M.J. (2012). "Sciurus stramineus (Rodentia: Sciuridae)". Mammalian Species. 44 (1): 44–50. doi:10.1644/894.1.
5. Jessen, R.R.; et al. (2010). "Presence of Guayaquil squirrels on the central coast of Peru: an apparent introduction". Mammalia. 74 (4): 443–444. doi:10.1515/MAMM.2010.057. S2CID 84987885.
6. Suarez-Davalos, V.; et al. (2010). "Microdistribution of sylvatic triatomine populations in central-coastal Ecuador". Journal of Medical Entomology. 47 (1): 80–88. doi:10.1603/033.047.0111. PMID 20180312. S2CID 25719767.