Discovery of the world’s highest-dwelling mammal

Abstract

Environmental limits of animal life are invariably revised when the animals themselves are investigated in their natural habitats. Here we report results of a scientific mountaineering expedition to survey the high-altitude rodent fauna of Volcán Llullaillaco in the Puna de Atacama of northern Chile, an effort motivated by video documentation of mice (genus Phyllotis) at a record altitude of 6,205 m. Among numerous trapping records at altitudes of >5,000 m, we captured a specimen of the yellow-rumped leaf-eared mouse (Phyllotis xanthopygus rupestris) on the very summit of Llullaillaco at 6,739 m. This summit specimen represents an altitudinal world record for mammals, far surpassing all specimen-based records from the Himalayas and other mountain ranges. This discovery suggests that we may have generally underestimated the altitudinal range limits and physiological tolerances of small mammals simply because the world’s high summits remain relatively unexplored by biologists.

Phylogenetic relationships among cryptic species of the Phyllotis xanthopygus complex (Rodentia, Cricetidae)

“…in the north and sea level to 5,070 m.a.s.l. in the south (Steppan, 1998; Steppan & Ramírez, 2015; Storz et al., 2020). Both, Pearson (1958) and Hershkovitz (1962) considered it as a subspecies of P. darwini .…”

“…Among these taxa, the leaf‐eared mouse, P. xanthopygus is the most widely distributed and one of the most common and dominant species in some habitats, with populations from central Peru to southern Argentina and Chile (Steppan & Ramírez, 2015), from sea level to 6,739 m.a.s.l. (Storz et al., 2020). The leaf‐eared mouse occurs in arid and semiarid Andean ecosystems and is mostly associated with rocky outcrops and cliffs in shrubby to herbaceous steppes.…”

Elevation patterns and critical environmental drivers of the taxonomic, functional, and phylogenetic diversity of small mammals in a karst mountain area

“…These taxa are particularly suitable for examining elevation patterns because they are commonly found along mountain slopes, have higher speciation rates and higher species turnover between habitats compared with larger mammals (Lopez et al., 2016). Indeed, a rodent species was recently discovered to be the world's highest dwelling mammal (Storz et al., 2020). In this context, small mammal communities are among the best models for disentangling the interplay between the facets of biodiversity.…”

Insights into an undescribed high‐elevation lake (6,170 m a.s.l.) on Volcán Llullaillaco: A physical and microbiological view

“…It is also the highest elevation archaeological site in the world because three frozen bodies of Inca children were found perfectly preserved near its summit on the Argentinian side (Previgliano et al, 2003); and it holds the highest elevation record for a mammal anywhere on Earth since the rodent Phyllotis xanthopygus rupestris was recently reported from the summit (Storz et al, 2020).…”