A comparative analysis of food-niche relationships and trophic guild structure in two assemblages of vertebrate predators differing in species richness: causes, correlations, and consequences

Oecologia ◽  
1987 ◽  
Vol 71 (3) ◽  
pp. 461-472 ◽  
Author(s):  
F. M. Jaksić ◽  
M. Delibes
Mammalia ◽  
2016 ◽  
Vol 80 (1) ◽  
Author(s):  
Mariano S. Sánchez

AbstractI evaluated bat assemblages in terms of species richness, relative abundance, trophic guild structure, and seasonal changes at three sites along of the Southern Yungas forests. A total of 854 individuals were captured, representing 25 species of three families, with an effort of 27,138 m of mist net opened per hour. Subtropical assemblages showed a similar structure to those from tropical landmark, with a dominance of frugivorous Phyllostomid; in addition, a few species were abundant, followed by a long tail of less common species. However, subtropical sites differed due to the dominance of the genus


1983 ◽  
Vol 61 (10) ◽  
pp. 2230-2241 ◽  
Author(s):  
Fabian M. Jaksić ◽  
H. Elizabeth Braker

Food-niche relationships of diurnal raptors have been claimed to be shaped by either competitive interactions or opportunistic feeding. We confront these alternatives by analyzing the patterns of prey use of five assemblages of falconiforms. Our results show that food-niche breadth is not a species property but is determined by the food resources locally available; neither does it become narrower in larger assemblages nor is it correlated with raptor size. Food-niche overlaps are frequently very high and do not become smaller in larger assemblages. Mean weight of prey taken is positively correlated with raptor weight within assemblages, but varies widely across assemblages, with a single species showing manyfold differences. Weight ratios between raptors contiguous in the size axis fall well below the 2.2–3.4 expected figures, nor are they negatively correlated with the amount of food-niche overlap. Normalized distance ratios (d/w) of spacing between raptors along the food-size axis are usually smaller than the expected 1. The five assemblages are organized in feeding guilds whose size is larger where fewer prey categories are available per raptor species. In most cases we found little support for predictions based on competition-structured assemblages. This is probably because of the opportunistic feeding behavior of raptors, and perhaps also because food might not be a limiting resource for them.


1996 ◽  
Vol 351 (1344) ◽  
pp. 1113-1129 ◽  

A review is undertaken of various concepts in community ecology that relate to observed patterns in nature; these are species richness, diversity, guild structure, niche structure, constancy of structure, succession and the bionomic profile of communities. This understanding may allow us to better predict the effects of changes we are making in our environment.


1995 ◽  
Vol 30 (2) ◽  
pp. 243-253 ◽  
Author(s):  
Leoš Klimeš ◽  
Jan Wim Jongepier ◽  
Ivana Jongepierová

2011 ◽  
Vol 6 (2) ◽  
pp. 246-259 ◽  
Author(s):  
Sophia Barinova ◽  
Alexey Petrov ◽  
Eviatar Nevo

AbstractComparative analysis of algal communities in the rivers of Israel was completed to highlight the influence of environmental variables on biodiversity. The study revealed that 671 species of algae and cyanobacteria belonging to nine taxonomic divisions were present during 2002–2009 in the Yarqon, Alexander, Hadera, Qishon, Oren, Lower and Upper Jordan, and Zin rivers. The species richness of each river was evaluated by taxonomic structural comparison, geobotanical, hierarchical cluster analysis, and the degree of relatedness for different levels of taxonomic resolution. The analysis revealed close similarity of the Upper Jordan and Oren rivers. The average taxonomic distinctness index showed that the Yarqon, Oren, Upper Jordan, and Qishon communities were partly degraded due to permanent environmental disturbances. The variation in taxonomic distinctness index showed that the Alexander, Yarqon and Hadera communities were formed not only due to anthropogenic factors but also through long-term climatic impact. The most abundant indicator species inhabit low streaming and standing alkaline waters of medium salinity and low to medium organic pollution. The statistical approaches allowed discrimination between climatic and anthropogenic factors that impact upon the riverine biodiversity in semi-arid environments. Analysis shows the influence of anthropogenic factors was strongly modulated by climatic impacts causing a marked decease of species richness from north to south.


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