Prey availability, prey selection, and trophic niche width in the lizard Psammodromus algirus along an elevational gradient  

作　　者：Gregorio MORENO-RUEDA Elena MELERO Senda REGUERA Francisco J, ZAMORA-CAMACHO Ines ALVAREZ-BENITO 

机构地区：[1]Departamento de Zoologla, Facultad de Ciencias, Universidad de Granada, Granada E-18071, Spain [2]Departamento de Biogeografia y Carnbio Global, Museo Nacional de Ciencias Naturales-CSIC, C/Jose Gutierrez Abascal 2, E-28006 Madrid, Spain

出　　处：《Current Zoology》2018年第5期603-613,共11页动物学报（英文版）

摘　　要：Mountains imply enormous environmental variation, with alpine habitats entailing harsh environ- ments, especially for ectotherms such as lizards. This environmental variability also may imply variation in prey availability. However, little is known about how lizard trophic ecology varies with elevation. In this study, we analyze diet, prey availability, prey selection, and trophic niche width in the lacertid lizard Psammodromus algirus along a 2,200-m elevational gradient in the Sierra Nevada （SE Spain）. The analysis of fecal samples has shown that Orthoptera, Formicidae, Hemiptera, Coleoptera, and Araneae are the main prey, although, according to their abundance in pitfall traps, Formicidae and Coleoptera are rejected by the lizard whereas Orthoptera, Hemiptera, and Araneae are preferred. Prey abundance and diversity increase with elevation and diet subtly varies along with the elevational gradient. The consumption of Coleoptera increases with elevation probably as a consequence of the lizard foraging more in open areas while basking. The electivity for Araneae increases with elevation. Araneae are rejected in the lowlands--where they are rela- tively abundant--whereas, at high elevation, this lizard positively selects them, despite they being less abundant. The lizard trophic niche width expands with elevation due to concomitant greater prey diversity and hence this lizard feeds on more prey types in highlands. Although no sex difference in diet has been found, the trophic niche is broader in females than males. As a whole, alpine lizards show a trophic niche simitar to that found at lower elevat（ons, suggesting that P. algirus is well adapted to the harsh environment found in alpine areas.

关 键 词：alpine habitats arthropods mountain ecology niche variation hypothesis trophic ecology 

分 类 号：Q959.62[生物学—动物学] Q959.838