{{Short description|Species of rodent}} {{speciesbox | image = Akodon longipilis - Museo Civico di Storia Naturale Giacomo Doria - Genoa, Italy - DSC02807.JPG | status = LC | status_system = IUCN3.1 | status_ref = <ref name=iucn>{{cite iucn|author1=D'elia, G.|author2=Pardinas, U.|author3=Patterson, B.|year=2016|title=''Abrothrix longipilis''|errata=2017|article-number=e.T743A115048280|doi=10.2305/IUCN.UK.2016-3.RLTS.T743A22337497.en|access-date=13 November 2025}}</ref> | genus = Abrothrix | species = longipilis | authority = (Waterhouse, 1837) | synonyms = *''Mus longipilis'' <small>Waterhouse, 1837</small> *''Akodon longipilis'' <small>(Waterhouse, 1837)</small> }}
'''''Abrothrix longipilis''''', also known as the '''long-haired grass mouse'''<ref name=iucn/> or '''long-haired akodont''',<ref name=MC1089>{{MSW3 Muroidea | id = 13000532 |heading=''Abrothrix longipilis''| pages = 1089–1090}}</ref> is a species of rodent in the family Cricetidae. It is endemic to central Argentina and Chile.<ref name=Estudio2014>{{Cite journal |title=Variación morfológica cualitativa y cuantitativa en Abrothrix longipilis (Cricetidae, Sigmodontinae) |journal=Mastozoología Neotropical |url=http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0327-93832014000200009 |last1=Teta |first1=Pablo |issue=2 |volume=21 |last2=Pardiñas |first2=Ulyses F. J. |year=2014 |language=Spanish |trans-title=Qualitative and quantitative morphological variation in ''Abrothrix longipilis'' (Cricetidae, Sigmodontinae)}}</ref> Until 2014 it was thought that the species extended into southern Chile and Argentine Patagonia but these populations are now proposed to belong to closely related species named ''Abrothrix hirta''.<ref name=Estudio2014/>
The southern Chilean ''Abrothrix sanborni'' may not be distinct from this species.<ref name=MC1089/>
==Description== The long-haired grass mouse is a large, robust grass mouse, with a head-and-body length of about {{cvt|130|mm|in|0}}. It varies in colour across its wide range, but in most populations the dorsal hair is reddish-brown with long guard hairs, the flanks are more greyish and the underparts are grey. The tail is bicoloured, dark above and pale below.<ref name=Patton>{{cite book|author=Patton, James L.|title=Mammals of South America|volume= 2: Rodents |url=https://books.google.com/books?id=4aHLBgAAQBAJ&pg=PA118 |year=2015|publisher=University of Chicago Press |isbn=978-0-226-16957-6 |pages=118–121}}</ref>
==Distribution and habitat== The species is found in central and southern Chile, and in Argentina as far southward as the Rio Negro and Chubut provinces of Patagonia. Its chief habitat is the ''Nothofagus'' forests of the region but it is also found in rocky areas, marshy areas, tussock grass and steppe with shrubs.<ref name=Patton/>
==Ecology== The long-haired grass mouse is active both in the day and the night. It is an efficient excavator and digs burrows, but it is also a good tree climber. In Argentina it feeds on berries, seeds, insects, slugs, worms, fungi and fern spores. The diet differs in different parts of Chile, either consisting of insects and plant material, or insects and fungi, just insects or just fungi.<ref name=Patton/> Breeding takes place in the spring and summer. The litter size averages just below four and at least some individuals overwinter twice. Home ranges in the Patagonian ''Nothofagus'' forest vary between 0.4 and 4.8 individuals per hectare in spring, and 2.8 to 10.8 individuals per hectare in autumn. This grass mouse is preyed on by the barn owl, the lesser horned owl, the rufous-legged owl, the white-tailed kite and the South American gray fox. It is also an important reservoir species for the Andes virus, which is a major causative agent of the disease Hantavirus cardiopulmonary syndrome.<ref name=Patton/>
==Status== ''A. longipilis'' has a wide range and is presumed to have a large total population. The population trend may be downward but it is an abundant species and the decline is not at a rate to cause concern, so the International Union for Conservation of Nature has rated its conservation status as being of "least concern".<ref name=iucn/>
==References== {{Wikispecies|Abrothrix longipilis}} {{Commons category}} {{Reflist|30em}}
==Literature cited== *{{MSW3 Muroidea}}
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{{Taxonbar|from=Q305861}}
Category:Mammals of Argentina Category:Mammals of Chile Category:Abrothrix Category:Mammals described in 1837 Category:Taxonomy articles created by Polbot