Unlocking Andean sigmodontine diversity: five new species ofChilomys(Rodentia: Cricetidae) from the montane forests of Ecuador

Abstract

The Andean cloud forests of Ecuador are home to several endemic mammals. Members of the Thomasomyini rodents are well represented in the Andes, with Thomasomys being the largest genus (47 species) of the subfamily Sigmodontinae. Within this tribe, however, there are genera that have escaped a taxonomic revision, and Chilomys Thomas, 1897, constitutes a paradigmatic example of these “forgotten” Andean cricetids. Described more than a century ago, current knowledge of this externally unmistakable montane rodent is very limited, and doubts persist as to whether or not it is monotypic. After several years of field efforts in Ecuador, a considerable quantity of specimens of Chilomys were collected from various localities representing both Andean chains. Based on an extensive genetic survey of the obtained material, we can demonstrate that what is currently treated as C. instans in Ecuador is a complex comprising at least five new species which are described in this paper. In addition, based on these noteworthy new evidence, we amend the generic diagnosis in detail, adding several key craniodental traits such as incisor procumbency and microdonty. These results indicate that Chilomys probably has a hidden additional diversity in large parts of the Colombian and Peruvian territories, inviting a necessary revision of the entire genus.

First national assessment of wildlife mortality in Ecuador: An effort from citizens and academia to collect roadkill data at country scale

“…Approximately 659 amphibian species (Ron et al, 2021 ), 500 reptile species (Torres‐Carvajal et al, 2022 ), 1699 bird species (Freile & Poveda, 2019 ), and 466 mammal species (Brito et al, 2021 ) have been described in Ecuador. Likely, these numbers are highly underestimated as new species are still regularly identified (e.g., Brito et al, 2022 ; Guayasamin et al, 2022 ; Leonan et al, 2022 ) and cryptic species are probably common (Funk et al, 2012 ). Ecuador is also a highly anthropized country transected by more than 16,647 km of primary and secondary roads (Meijer et al, 2018 ).…”

New species of the Spiny Mouse genus Neacomys (Cricetidae, Sigmodontinae) from northwestern Ecuador

“…It is important to mention that after more than two centuries of active research in mastozoology ( Tirira 2014 ), intensive fieldwork was conducted in few places in Ecuador. Examples for those sites in the eastern Andes are Papallacta ( Voss 2003 ), Guandera Biological Reserve ( Lee et al 2015 ), and Sangay National Park ( Brito and Ojala-Barbour 2016 ), and in the western Andes are Cajas National Park ( Barnett 1999 ), Otonga Reserve ( Jarrín 2001 ), Pululahua Geobotanical Reserve ( Curay et al 2019 ), Polylepis Forest ( Ojala-Barbour et al 2019 ), Reserva Dracula ( Brito et al 2020 , 2022a ), and Lita ( Curay et al 2022 ). The interest in complementary biodiversity studies has led to the prioritization of intensive field work, using a variety of trapping techniques (e.g., live traps, spring traps, and pitfall traps), and has also triggered revisions of museum specimens.…”

“…The interest in complementary biodiversity studies has led to the prioritization of intensive field work, using a variety of trapping techniques (e.g., live traps, spring traps, and pitfall traps), and has also triggered revisions of museum specimens. For example, in the last five years, these approaches have led to the description of at least 14 new sigmodontine: five Chilomys (see Brito et al, 2022a ), three Thomasomys (see Brito et al 2019 ; Brito et al 2021b ; Lee et al 2022 ), one Tanyuromys (see Timm et al 2018 ), one Ichthyomys (Fernández de Córdova et al 2020), two Pattonimus ( Brito et al 2020 ), one Neacomys ( Brito et al 2021a ), and one Mindomys ( Brito et al 2022b ). This burgeoning richness will surely reorganize part of our understanding of Neotropical cricetids.…”

Sistemática, distribución y adaptaciones de los Caenolestidae vivientes (Mammalia, Marsupialia, Paucituberculata)

“…La abundancia relativa está sesgada a un mayor número de machos en general y se ha observado un aumento en abundancia durante la transición seca a lluviosa en Colombia, pero más datos son necesarios para conocer si esto es una característica de la especie, ya que esta información proviene de estudios puntuales y de solo dos localidades (González-Chávez et al, 2019;Lopez-Arevalo et al, 1993). Las especies de Caenolestes son frecuentemente atrapadas junto con roedores de los géneros Thomasomys, Microryzomys, Chilomys, Akodon, Oryzomys, Nephelomys, Rhipidomys, Heteromys y Reithrodontomys y, comúnmente, junto con individuos del género de musarañas Cryptotis y marsupiales del género Marmosa y Marmosops (Barnett, 1991;Brito, Tinoco, et al, 2022;González-Chávez et al, 2019;Lopez-Arevalo et al, 1993;González & Martin, datos inéditos).…”