Kuhnen Vanessa Villanova, Romero Gustavo Quevedo, Linhares Arício Xavier, Vizentin-Bugoni Jeferson, Porto Erica Aline Correa, Setz Eleonore Zulnara Freire
Pós-Graduação em Ecologia, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, São Paulo, Brazil.
Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, São Paulo, Brazil.
PLoS One. 2017 Jul 12;12(7):e0181188. doi: 10.1371/journal.pone.0181188. eCollection 2017.
Species co-existence depends on how organisms utilize their environment and resources. When two sympatric species are similar in some ecological requirements, their coexistence may arise from differences in resource use over time and/or space. Interactions among coexisting marsupials remain poorly understood, especially in the Neotropics. Here we combine spatial niche measurements, individual-resource networks, and isotopic niche approaches, to investigate the ecological strategies used by the Neotropical marsupials Didelphis aurita and Metachirus nudicaudatus to co-occur in an area of Serra do Mar State Park (southeast of Brazil). Both individual-resource networks and isotopic niche approaches indicate similar patterns of omnivory for both species. Isotopic analysis showed the species' trophic niche to be similar, with 52% of overlap, and no differences between proportional contributions of each resource to their diets. Moreover, individual-resource network analysis found no evidence of diet nestedness or segregation. The trophic niche overlap observed was associated with spatial segregation between species. Despite using the same area over the year, D. aurita and M. nudicaudatus exhibited spatial segregation among seasons. These results illustrate that the detection of spatial segregation is scale-dependent and must be carefully considered. In conclusion, our findings provide a new perspective on the ecology of these two Neotropical marsupials by illustrating how the association of distinct but complementary methods can be applied to reach a more complete understanding of resource partitioning and species coexistence.
物种共存取决于生物体如何利用其环境和资源。当两个同域物种在某些生态需求上相似时，它们的共存可能源于在时间和/或空间上资源利用的差异。共存有袋动物之间的相互作用仍知之甚少，尤其是在新热带地区。在这里，我们结合空间生态位测量、个体-资源网络和同位素生态位方法，来研究新热带有袋动物南美袋鼬和裸尾袋鼹在巴西东南部滨海山脉国家公园的一个区域中共存所采用的生态策略。个体-资源网络和同位素生态位方法都表明这两个物种的杂食模式相似。同位素分析表明，这两个物种的营养生态位相似，重叠率为52%，且每种资源在它们饮食中的比例贡献没有差异。此外，个体-资源网络分析没有发现饮食嵌套或隔离的证据。观察到的营养生态位重叠与物种间的空间隔离有关。尽管全年使用相同的区域，但南美袋鼬和裸尾袋鼹在不同季节表现出空间隔离。这些结果表明，空间隔离的检测是依赖尺度的，必须仔细考虑。总之，我们的研究结果通过说明如何应用不同但互补的方法来更全面地理解资源分配和物种共存，为这两种新热带有袋动物的生态学提供了一个新视角。
