Morphological variation in two sigmodontine rodents along the mainland and the Fuegian archipelago in Chilean southern Patagonia

Valladares-Gomez, Alejandro; Huenumilla-Linares, Marcela; Rodriguez-Serrano, Enrique; Hernandez, Cristian E.; Palma, R. Eduardo

Abstract

Background Analysis of morphological variation in archipelagos has been essential to understand the evolution of terrestrial vertebrates. In particular, these natural scenarios allow to assess morphological changes experienced by insular fauna compared to their mainland counterparts. In mammals, morphological changes of insular forms have been observed in size and shape of body and cranial traits. The southern Patagonia of Chile represents a unique scenario to analyze morphological variation in two of the most widely distributed small rodents along western southern South America:Abrothrix olivaceaandOligoryzomys longicaudatus. Methods We applied linear and three-dimensional geometric morphometric tools to analyze the variation in cranial morphology ofA. olivacea(N = 80) andO. longicaudatus(N = 49).Sampled localities were distributed in the mainland and islands of the Fuegian archipelago in Chilean Patagonia. Standard multivariate methods, as Principal Components Analysis, and Logistic Regression models were carried out to evaluate differences in size and shape of crania. Results We detected higher levels of morphological variation in the crania ofA. olivaceaif compared toO. longicaudatus. The variation was associated to cranial size instead of shape. We observed significant differences between insular and mainland individuals inA. olivacea, being the cranium size of this species significantly bigger on islands. Indeed, specimens ofA. olivaceafrom "Isla Wellington", exhibited the higher increment in cranium size compared to any other mainland and insular site sampled for this species.In contrast, insular and mainland forms ofO. longicaudatusdid not show significant differences in cranial morphology. Conclusions We suggest that the patterns of morphological variation observed in these two small rodents along Patagonia, could be explained in terms of the historical biogeography of the region, and the different ecological features of the studied species.

Más información

Título según WOS: ID WOS:000548665700001 Not found in local WOS DB
Título de la Revista: Revista Chilena de Historia Natural
Volumen: 93
Número: 1
Editorial: SOC BIOLGIA CHILE
Fecha de publicación: 2020
DOI:

10.1186/s40693-020-00094-9

Notas: ISI