Southern tuco-tuco (Ctenomys australis)

Mohamed bin Zayed Species project number 242535358

Assessing the conservation status and population management of the Southern Tuco-tuco and the Beautiful Tuco-tuco in Buenos Aires coastal ecosystems

Ctenomys australis, the Southern Tuco-tuco, is an endemic and threatened species considered Endangered (EN) by the IUCN Red List, and the assessment by the Sociedad Argentina para el Estudio de los Mamíferos (SAREM). These evaluations have considered the populations to be decreasing and threatened by habitat loss, which is significant for a species with a linear distribution (coastal line) and an extent of occurrence (EOO) with less of 500 km². Recently, Ctenomys pulcer (Beautiful Tuco-tuco) was described, but its conservation status has not yet been assessed. Both species inhabit the Pampean sand-dune grasslands along the coast of Buenos Aires Province, feeding exclusively on the native vegetation of this ecosystem. Habitat loss and fragmentation due to urbanization, exotic plantations to stabilize the active dunes, tourism activities, and wind energy are local stressors for these subterranean rodents. We believe that Ctenomys pulcer is experiencing significant stress within its populations due to its smaller distribution range and the same threats faced by Ctenomys australis. Our project will contribute to the assessment of the conservation status of these Ctenomys species and involve local stakeholders and communities in their conservation as well as the protection of the Southern Pampas Dune ecosystem. Our objectives are: 
• We will construct distribution models for Ctenomys australis and Ctenomys pulcer using high-resolution satellite images from Sentinel 2A to estimate their suitable habitats. 
• We will determine the Extent of Occurrence (EOO)and Area of Occupancy (AOO) of each species, and this key information will be used for their conservation status assessment. 
• We will investigate the genetic variation of both species across their distribution ranges and identify evolutionary significant units (ESUs) to facilitate effective population management. Genomic tools such as single nucleotide polymorphisms (SNPs) will be employed to compare with previous data generated using mitochondrial markers. This model for these two endemic species of subterranean rodents from Buenos Aires Province is unique not only in its use of SNPs as genomic markers in conservation genetics and landscape studies but also because these species exhibit sympatric distributions in certain coastal areas. They maintain high specificity to dune environments, particularly Ctenomys australis (Austrich et al. 2021). 
• We will identify the main local threats to the Ctenomys species and conduct outreach activities to mitigate these pressures.
Currently, we are working in field expeditions and laboratory DNA extractions for sequencing.
Some exciting news on our project soon.