Conservation status and natural history of Ctenomys, tuco-tucos in Bolivia

Abstract

The genus Ctenomys consists of about 70 species and in addition to the Geomyidae of the Nearctic, Neotropical tuco-tucos represent a well-documented case of diversification in the subterranean biotype. Here we will: i) Provide an updated summary of the natural history of the 12 species of extant tuco-tucos from Bolivia; ii) Update information on distributions of each species; and iii) Using ecological niche modeling, evaluate recent and projected habitat transformation or habitat degradation within the known range of each species to provide a preliminary assessment of the preservation or conservation status of ctenomyids within Bolivia. We follow Gardner et al. (2014) and combine species summaries with both updated published and new data to compile a complete list of known extant species of tuco-tucos from Bolivia. Occurrence data for Ctenomys in Bolivia and surrounding areas were extracted from the database Arctos and GBIF. All individual specimen-based locality records were checked and georeferenced by referring to original museum collection records. We created species distribution models for the species with enough locality records using climate and soil data, while for the rest of the species we estimated the ranges based on the known occurrence localities. Finally, we quantified the amount of large-scale habitat conversion occurring within each species range, as well as the potential effect of climatic change on species distribution. Here we present information regarding the biology of tuco-tuco (Ctenomys) species known to occur in Bolivia, including unpublished natural history data such as habitat association, interactions and activity patterns gathered by the authors through extensive field work. Besides this, we estimated the current distribution of Ctenomys species, quantified large-scale habitat transformation within each species range and assessed the potential effect of climatic change on five tuco-tuco species. We found that the habitats within the ranges of C. boliviensis and C. steinbachi have experienced significant land-cover conversions in recent years. We also show that C. opimus, as well as the above mentioned species are expected to undergo range contractions resulting from climatic change by 2070. Our review shows that there is a dearth of information regarding natural history, taxonomy and distribution for many Bolivian tuco-tuco species. Nonetheless, the information presented here can be a tool for directing and focusing field studies of these species. This is of great importance if we take into account that most of the Bolivian tuco-tucos are subject to one or several conservation/preservation threats. These include: Habitat destruction via land use or climatic changes in conjunction with geographic ranges of Ctenomys that are small in areal extent and which in many cases are not adequately covered by protected areas.

Filling the gap in distribution ranges and conservation status in Ctenomys (Rodentia: Ctenomyidae)

“…Species distribution shapes.— In this study, we used data generated by the reassessment of Argentinian species performed by MAyDS and SAREM (http://cma.sarem.org.ar), as well as those of Bolivian species evaluated by Gardner et al (2021), and we provide a detailed justification of any departure in the use of this material that could result from ulterior taxonomic definitions or the discovery of unstudied populations. In the case of Argentinean species, DAs were created based on extent of occurrence polygons (EOOP), extrapolated by expert criteria around habitats considered as suitable for the species, considering other factors that may limit distribution in geographic space such as elevation, temperature, or natural physical barriers.…”

“…In the case of Argentinean species, DAs were created based on extent of occurrence polygons (EOOP), extrapolated by expert criteria around habitats considered as suitable for the species, considering other factors that may limit distribution in geographic space such as elevation, temperature, or natural physical barriers. For five Bolivian species, the estimated DA was further refined using the ecological niche modeling approach detailed in Gardner et al (2021), and considering environmental variables such as soil composition, elevation, and temperature. Some of the DAs for these species result in disjunct polygons, and others show empty spaces within polygons.…”

“…These attributes, together with factors such as anthropogenic habitat fragmentation and habitat degradation, climatic change, urbanization, and limited knowledge of the geographic occurrence of these rodents increase the risk of extinction at both the population and the species levels (Gallardo et al 1996; Gómez Fernández et al 2016). In a recent study of all known Bolivian species of Ctenomys , Gardner et al (2021) quantified large-scale habitat transformation within each species range and assessed the potential effect of climatic change on five of these species. Most Bolivian tuco-tuco species have suffered significant range contractions due to anthropogenic land cover change, which will be most likely be exacerbated in the near future by rapidly changing climatic conditions.…”

“…Since most of the species of Ctenomys (45 out of 64, see below) occur in Argentina, the outcome of this effort is a crucial advancement toward having more precise information on distributional ranges and to study the potential for conservation of these species in PAs. Similarly, Gardner et al (2021) have updated information on distributions of each species and provided a preliminary assessment of the preservation or conservation status of tuco-tucos within Bolivia. Despite these valuable efforts, around half of the species of Ctenomys have been categorized by the IUCN as Data Deficient (DD) due to insufficient information for a proper assessment of their conservation status, or remain NE.…”

Helminth and protozoan parasites of subterranean rodents (Chordata, Mammalia, Rodentia) of the world

“…Rossin et al (2004a) reported larvae of Hydatigera (syn. Taenia) taeniaeformis from the peritoneal cavity and liver of the Talas tuco-tuco, Ctenomys talarum, trapped in the Lambert et al, 1988Lambert et al 1988Gardner andDuszynski Eimeria montuosi Lambert et al, 1988 Lambert et al 1988;Gardner andDuszynski Eimeria opimi Lambert et al, 1988 Lambert et al 1988;Gardner andDuszynski Eimeria oruroensis Lambert et al, 1988 Lambert et al 1988;Gardner andDuszynski Litomosoides andersoni Brant &Gardner, 1997 Brant andGardner 1997 Litomosoides ctenomyos Brant & Gardner, 1997Brant and Gardner 1997Mathevotaenia Akhumyan, 1946Gardner et al 2021, 2023 Ctenomys pearsoni Lessa & Langguth, 1983Strongyloides myopotami Artigas & Pacheco, 1933Rossin et al 2009 Ctenomys steinbachi Thomas, 1907 Ancylostoma ctenomyos Drabik &Gardner, 2019 Drabik andGardner 2019 Eimeria opimi Lambert et al, 1988Gardner and Duszynski 1990Paraspidodera Travassos, 1914Gardner et al 2021 Ctenomys talarum Thomas, 1898 Graphidiodes subterraneus Rossin et al, 2005Rossin et al 2005bRossin et al 2010bHeligmostrongylus Travassos, 1917Rossin and Malizia 2002 Paraspidodera uncinata Rudolphi, 1819 Rossin et al 2004b;Rossin et al 2010b Pudica ctenomydis Rossin et al, 2006…”