A new climbing shrew from Sulawesi highlights the tangled taxonomy of an endemic radiation

Abstract

We describe a new species of Crocidura (Soricidae) from Sulawesi Island, Indonesia, documenting its novelty with both genetic and morphological characters. The new species is widespread on the island, with vouchered records from nine general localities distributed among five of the island’s areas of endemism. Morphologically, the new species is readily distinguished from all other described Sulawesi Crocidura by its intermediate body size, gray pelage, and long, hairy tail. The new species was mainly captured in pitfalls placed in the ground, but we also obtained evidence that it readily climbs trees and may be scansorial in its locomotor habits. Populations of the new species sampled from across the island are closely related, separated by < 0.02 uncorrected mitochondrial p-distances. The new species is one member of an endemic radiation of shrews on Sulawesi now known to contain six valid species and several undescribed species, all within the genus Crocidura. Resolution of species limits and phylogenetic relationships in this radiation is hindered by habitat loss at type localities, historical designation of new species using very small sample sizes, and a lack of genetic data from type specimens. Kami mendeskripsikan spesies baru Crocidura (Soricidae) dari Pulau Sulawesi, Indonesia, sekaligus mendokumentasikan keunikan karakter secara genetik maupun morfologi dari spesies tersebut. Spesies baru ini tersebar luas di Pulau Sulawesi, diketahui berdasarkan spesimen yang berasal dari sembilan lokasi umum yang tersebar di lima kawasan endemik di pulau tersebut. Secara morfologi, spesies baru ini dapat dibedakan dari spesies Crocidura lainnya dari Sulawesi berdasarkan ukuran tubuh yang sedang, rambut tubuh berwarna abu-abu, dan ekor yang panjang dan berambut. Spesies baru ini sebagian besar diperoleh dari perangkap sumuran yang ditanam didalam tanah, selain itu kami juga mendapatkan bukti bahwa spesies ini mampu memanjat pohon dan kemungkinan memiliki perilaku sebagai pemanjat. Beberapa populasi spesies yang dikoleksi dari Sulawesi ini mempunyai kekerabatan yang dekat, hanya dipisahkan oleh jarak proporsi DNA mitokondria (tidak terkoreksi) sebesar < 0.02. Spesies baru ini merupakan salah satu anggota dari suatu kelompok radiasi endemik cecurut di Sulawesi yang sampai saat ini diketahui terdiri atas enam spesies yang valid, dan beberapa spesies yang belum dideskripsikan, semuanya termasuk didalam genus Crocidura. Kepastian dalam menetapkan batasan jarak antar spesies dan hubungan kekerabatan genetik dari radiasi kelompok cecurut di Sulawesi terkendala oleh kerusakan habitat pada lokasi spesimen tipe, sejarah penamaan spesies yang hanya berdasarkan sampel yang sedikit, dan keterbatasan data molekuler dari spesimen tipe.

Fourteen New, Endemic Species of Shrew (Genus Crocidura) from Sulawesi Reveal a Spectacular Island Radiation

“…The type localities for the only two Crocidura described from the island since 1921 are Mt. Rorekatimbo (west-central area of endemism) for C. musseri Ruedi (1995) and Mt. Dako (north-west area of endemism) for C. caudipilosa Esselstyn et al (2019).…”

“…The early Raven collections include the types of five (Crocidura elongata, C. lea, C. levicula, C. nigripes, and C. rhoditis) of the seven currently recognized species of Sulawesi shrew (Miller and Hollister, 1921). The remaining two species (C. musseri and C. caudipilosa) were described by Ruedi (1995) and Esselstyn et al (2019). A complete, georeferenced list of localities from which we examined specimens for this study is provided in the appendix.…”

“…We did not include Crocidura nigripes in this sequencing effort because it is phenotypically distinctive and phylogenetically distant from other Sulawesi taxa. More recently described species (C. musseri and C. caudipilosa) have published genetic data available from the type series Esselstyn et al, 2019), and we used those published sequences in our inferences.…”

“…Only the genus Crocidura is naturally present (the nonnative Suncus murinus may be found around human habitations), and seven species are currently recognized, but that figure is an underestimate; several studies have reported or suggested the presence of undescribed and unidentified species (e.g., Musser, 1982Musser, , 1987Ruedi, 1995;Eldridge et al, 2018;Esselstyn et al, 2019). Among the seven currently documented species, six form a clade, while the remaining taxon (C. nigripes) is more closely related to species on other islands to the west Esselstyn et al, , 2019Hinckley et al, 2021). This suggests that most of Sulawesi's shrew diversity arose through in situ diversification after the arrival of a single colonizing ancestor .…”

Mammalian research honoring the educational contributions of Grinnell Awardee Robert M. Timm

“…In this Special Feature, many of Bob's Ph.D. students offer contributions illustrating two themes that have consistently run through his research: 1) small mammals, and 2) New World mammals, as well as the breadth of his knowledge and interests (Beasley and Maher 2019;Esselstyn et al 2019;McCain 2019;Soley-Guardia et al 2019;Vieira et al 2019;Woodman and Wilken 2019;York et al 2019). Although Bob's graduate students were and remain fiercely independent in their research (a quality he probably sought out, and certainly encouraged), this collection of manuscripts encapsulates his own interests remarkably well.…”