Spatial and temporal segregation allows coexistence in a hybrid zone among two Mediterranean vipers (Vipera aspis and V. latastei)

• Type: Article in International Scientific Journal
• Date: 2010

Authors

martinez-freiria, f (Author) Other; lizana, m (Author) Other; do amaral, jp (Author) Other; brito, jc (Author) FCUP

Journal

Title: Amphibia - Reptilia

Vol. 31

Pages: 195-212

ISSN: 0173-5373

Publisher: Brill

Indexing

ISI Web of Knowledge - 6 Citations

Scopus - 7 Citations

Scientific classification

FOS: Natural sciences > Biological sciences

Other information

Authenticus ID: P-003-A22

DOI: 10.1163/156853810791069001

Abstract (EN): Mediterranean vipers are ecologically very similar. When in contact, they constitute an exceptional model to study the effects of competitive interactions and niche segregation mechanisms. In High Ebro, distinct methodologies (random visual encounter, road sampling and radio-tracking surveys, captive maintenance, standardized transects and ad hoc field observations) were used to compare ecological traits (diet, micro-habitat, activity, reproductive and demographic) of V. aspis, V. latastei and hybrids among both species and determine competitive advantages of each form. Diet preferences were similar but few differences were found in feeding frequency and annual variation in diet consumption. Males of the three forms compete for areas with similar characteristics but differences were found mainly during summer. Significant differences in average movement rates and home range size were found among males. Fecundity and new-borns fitness were lower in V. aspis than in V. latastei, whereas hybrids had intermediate values. Male and female adult hybrids were more abundant than parental forms, whereas female and juvenile V. latastei and juvenile hybrids had high road-mortality. The three forms seem to be competing intensely for resources but the segregation on the spatial and temporal axes of their niches could be reducing interspecific competition and allowing coexistence. The use of different resources probably confers reproductive and demographic advantages for V. latastei and hybrids, respectively. Moreover, reproductive fitness of hybrids suggests the occurrence of endogenous selection. Comparative thermal and genetic studies are needed to clarify the limiting factors of vipers and to establish a model of the hybrid zone.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 18