Niche differentiation in Neotropical singing mice
Pino J.L., Soto-Centeno J.A. and Pasch B. 2013. Niche differentiation in Neotropical singing mice. In: Hortal, J., Faller, K., Feeley, K., Field, R., Graham, C., Guilhaumon, F. & Gavin, D., eds. Conference program and abstracts. International Biogeography Society 6th Biennial Meeting, 9-13 January 2013; Miami, Florida, USA. Frontiers of Biogeography Vol. 4, suppl. 1. International Biogeography Society, 230 pp.
ABSTRACT: Species distributions inferred from ecological niche models (ENM) assume accurate estimation of conditions in which species can survive and their corresponding geographic limits. Sister species of Neotropical singing mice (genus Scotinomys) segre- gate altitudinally in the highlands of Costa Rica and Panamá, where S. teguina occurs from ~1000-2900m and S. xerampelinus inhabits regions above 2100m. Previous data suggests that S. xerampelinus is limited by abiotic factors, whereas S. teguina is limited by the presence of dominant heterospecifics. We used ENM and C13 and N15 stable isotope data from hair samples to further explore the factors mediating altitudinal segregation. Predictive performance of ENM was high for both S. teguina and S. xerampelinus (AUC= 0.91 and 0.96, respectively). Interestingly, both ENM and isotope analyses showed the niche of S. xerampelinus to be nested within that of S. teguina (>95% for ENM, 71% for isotopes). Furthermore, the predicted distribu- tion of S. teguina was ~30% larger in the absence of S. xerampelinus, supporting earlier findings of competitive exclusion. Our data suggest that biotic and abiotic factors interact to mediate the altitudinal distributions of Neotropical singing mice, and highlight the importance of integrating biotic and abiotic data to assess the accuracy and magnitude of niche differentiation.
ABSTRACT: Species distributions inferred from ecological niche models (ENM) assume accurate estimation of conditions in which species can survive and their corresponding geographic limits. Sister species of Neotropical singing mice (genus Scotinomys) segre- gate altitudinally in the highlands of Costa Rica and Panamá, where S. teguina occurs from ~1000-2900m and S. xerampelinus inhabits regions above 2100m. Previous data suggests that S. xerampelinus is limited by abiotic factors, whereas S. teguina is limited by the presence of dominant heterospecifics. We used ENM and C13 and N15 stable isotope data from hair samples to further explore the factors mediating altitudinal segregation. Predictive performance of ENM was high for both S. teguina and S. xerampelinus (AUC= 0.91 and 0.96, respectively). Interestingly, both ENM and isotope analyses showed the niche of S. xerampelinus to be nested within that of S. teguina (>95% for ENM, 71% for isotopes). Furthermore, the predicted distribu- tion of S. teguina was ~30% larger in the absence of S. xerampelinus, supporting earlier findings of competitive exclusion. Our data suggest that biotic and abiotic factors interact to mediate the altitudinal distributions of Neotropical singing mice, and highlight the importance of integrating biotic and abiotic data to assess the accuracy and magnitude of niche differentiation.