Mearns red squirrel

Mearns red squirrel
	Mearns red squirrel ( Tamiasciurus douglasii mearnsi )
Systematics
Family :	Squirrel (Sciuridae)
Subfamily :	Tree squirrel and flying squirrel (Sciurinae)
Tribe :	Tree squirrel (Sciurini)
Genre :	Red squirrel ( Tamiasciurus )
Type :	Douglas squirrel ( Tamiasciurus douglasii )
Subspecies :	Mearns red squirrel
Scientific name
	Tamiasciurus douglasii mearnsi
	Townsend , 1897

The Mearns's Squirrel ( Tamiasciurus douglasii mearnsi , synonym : Tamiasciurus mearnsi ), also called Mearns croissant refers to is a rodent from the kind of red squirrel ( Tamiasciurus ) within the croissant (Sciuridae). According to current taxonomy, it is a subspecies of the Douglas squirrel ( Tamiasciurus douglasii ), but is often regarded as an independent species in older literature. The animals are found in Mexico, the species name honors the American zoologist Edgar Alexander Mearns .

features

The Mearns red squirrel reaches a head-to-trunk length of 187.8 to 214.2 mm in both sexes . The back and head are gray with a brownish tinge that runs from behind the ears to the middle of the back. The white belly is bordered by a gray to dark gray side stripe. The feet are light yellowish-white to gray. The ear brushes are made up of dense blackish brush hair. A white ring runs around the eyes. The tail is covered with black hair that has whitish, gray and yellowish tips.

distribution and habitat

The Mearns red squirrel occurs only in three places in the Sierra de San Pedro Mártir in the north of the Mexican state Baja California . The three places are each 10 km apart. The Mearns red squirrel lives in pine and fir forests at altitudes between 2100 and 2750 m.

Vocalizations

There are three known calls: a call that resembles the territorial rattle of its relatives but is apparently more shrill, a "chirp" call when the animal is irritated and a bark when it is startled.

Way of life

In contrast to its relatives, the common red squirrel ( Tamiasciurus hudsonicus ) and the Douglas squirrel ( Tamiasciurus douglasii ), the Mearns red squirrel does not store cones in pits or in goblets, but relies on the nesting holes in the trees. Males ready to mate were observed in May, with up to three males chasing a female with a swollen pink vulva . The food of the Mearns red squirrel consists primarily of cones of the Jeffrey pine ( Pinus jeffreyi ) and the Colorado fir ( Abies concolor ). The branch tips of the Colorado fir and the fungus Cryptoporus volvatus , which grows on the upper trunks of the Colorado fir, enrich the food supply. Predators include coyotes , bobcats, and likely birds of prey .

Systematics

The Mearns red squirrel is classified as an isolated subspecies of the Douglas squirrel ( Tamiasciurus douglasii ), but other plants also consider it to be an independent species within the red squirrel ( Tamasciurus ). The first scientific description comes from Charles Haskins Townsend from 1897, who described it from the Sierra de San Pedro Mártir in northern Baja California .

status

The IUCN classifies the Mearns red squirrel in the “endangered” category . No information is available on the population, but the species is generally considered rare. Possible threats are timber felling, grazing animals, forest fires and competition with the gray squirrel ( Sciurus carolinensis ) introduced in 1946 .

supporting documents

↑ ^a ^b ^c ^d J.L. Koprowski, EA Goldstein, KR Bennett, C. Pereira Mendes: Douglas's Squirrel. In: Don E. Wilson, TE Lacher, Jr., Russell A. Mittermeier (Eds.): Handbook of the Mammals of the World: Lagomorphs and Rodents 1. (HMW, Volume 6) Lynx Edicions, Barcelona 2016, p. 739 -740, ISBN 978-84-941892-3-4 .

↑ ^a ^b Richard W. Thorington Jr., John L. Koprowski, Michael A. Steele: Squirrels of the World. Johns Hopkins University Press, Baltimore MD 2012, ISBN 978-1-4214-0469-1 , pp. 82-84.

↑ ^a ^b Tamiasciurus mearnsi In: Don E. Wilson, DeeAnn M. Reeder (Ed.): Mammal Species of the World. A taxonomic and geographic Reference. 2 volumes. 3. Edition. Johns Hopkins University Press, Baltimore MD 2005, ISBN 0-8018-8221-4 .

↑ Tamiasciurus mearnsi in the IUCN Red List of Threatened Species 2013.1. Posted by: de Grammont, PC & Cuarón, A., 2008. Retrieved October 19, 2013.

literature

Richard W. Thorington Jr., John L. Koprowski, Michael A. Steele: Squirrels of the World. Johns Hopkins University Press, Baltimore MD 2012, ISBN 978-1-4214-0469-1 , pp. 82-84.
John L. Koprowski, Nicolás Ramos, Bret S. Pasch, Claire A. Zugmeyer: Observation on the ecology of the endemic Mearn's Squirrel (Tamiasciurus mearnsi). (PDF; 179 kB) In: The Southwestern Naturalist. Vol. 51, No. 3, 2006, ISSN 0038-4909 , pp. 426-430.

Web links

Tamiasciurus mearnsi inthe IUCN Red List of Threatened Species 2013.1. Posted by: de Grammont, PC & Cuarón, A., 2008. Retrieved October 19, 2013.

[Koprowski_et_al._2016-1] J.L. Koprowski, EA Goldstein, KR Bennett, C. Pereira Mendes: Douglas's Squirrel. In: Don E. Wilson, TE Lacher, Jr., Russell A. Mittermeier (Eds.): Handbook of the Mammals of the World: Lagomorphs and Rodents 1. (HMW, Volume 6) Lynx Edicions, Barcelona 2016, p. 739 -740, ISBN 978-84-941892-3-4 .

[Thorington_2012-2] Richard W. Thorington Jr., John L. Koprowski, Michael A. Steele: Squirrels of the World. Johns Hopkins University Press, Baltimore MD 2012, ISBN 978-1-4214-0469-1 , pp. 82-84.

[Wilson_et_al._2005-3] Tamiasciurus mearnsi In: Don E. Wilson, DeeAnn M. Reeder (Ed.): Mammal Species of the World. A taxonomic and geographic Reference. 2 volumes. 3. Edition. Johns Hopkins University Press, Baltimore MD 2005, ISBN 0-8018-8221-4 .