Trophic niche and home range of an insular pit viper following loss of food resources

2021 ◽  
Author(s):  
M. R. Sandfoss ◽  
M. D. McCue ◽  
H. B. Lillywhite
Keyword(s):  
Home Range ◽  
Food Resources ◽  
Trophic Niche

scholarly journals Trophic niche comparison between two predators in northern Rio de Janeiro State, Brazil: a stable isotopes approach

2013 ◽  
Vol 13 (3) ◽  
pp. 29-33 ◽  
Author(s):  
Ana Paula Madeira Di Beneditto ◽  
Carlos Eduardo Rezende ◽  
Plínio Barbosa Camargo ◽  
Helena Amaral Kehrig
Keyword(s):  
Food Chain ◽  
Rio De Janeiro ◽  
Trophic Position ◽  
Food Resources ◽  
Trophic Niche ◽  
Eastern Brazil ◽  
Trichiurus Lepturus ◽  
Δ15n And Δ13c ◽  
Pontoporia Blainvillei ◽  
Janeiro State

The trophic niche of the sympatric predators Pontoporia blainvillei(franciscana dolphin) and Trichiurus lepturus (ribbonfish) was compared by stable isotope (δ15N and δ13C) ratios in hepatic and muscular tissues to understand how they co-exist in the northern Rio de Janeiro State (21°30′S-22°15′S), south-eastern Brazil. Dolphin specimens were incidentally captured through commercial gillnet fisheries, while fish specimens were the target of these fisheries. The predators had similar δ15N values in the liver (P. blainvillei: 14.6 ± 1.0‰; T. lepturus: 14.4 ± 0.6‰), which indicates similar trophic position in the recent food intake. However,P. blainvillei showed lighter δ15N values in muscle (13.8 ± 1.0‰) than T. lepturus (15.0 ± 0.4‰), revealing differences in the long term diet that could be related with the prey size ingested. The δ13C signatures showed a preferential inshore and benthic food chain for P. blainvillei (liver: −15.2 ± 0.6‰; muscle: −16.0 ± 0.5‰) and a more offshore and pelagic food chain for T. lepturus(liver: −17.2 ± 0.6‰; muscle: −16.8 ± 0.3‰). The isotopic variances of liver and muscle revealed a broader niche width to P. blainvillei in relation to T. lepturus, with a greater use of available food resources in coastal waters. In the area of study, the differences in habitat use and exploitation of food resources are favoring the predators' coexistence.

scholarly journals Forest fragmentation influences the diet of cichlids Apistogramma agassizii (Steindachner, 1875) and Aequidens tetramerus (Heckel, 1840) (Actinopterygii: Cichliformes) in streams of the Western Amazon

2020 ◽  
Vol 32 ◽  
Author(s):  
Lucena Rocha Virgilio ◽  
Cleyton Holanda de Brito ◽  
Monik da Silveira Suçuarana ◽  
Lisandro Juno Soares Vieira
Keyword(s):  
Forest Fragmentation ◽  
Riparian Vegetation ◽  
Niche Overlap ◽  
Food Resources ◽  
Trophic Niche ◽  
Insect Larvae ◽  
Forest Environment ◽  
Low Amplitude ◽  
Diptera Larvae

Abstract: Aims To evaluate the effects of replacing riparian vegetation with pasture in the diet of Apistogramma agassizii and Aequidens tetramerus. Methods The study was carried out in the municipality of Senador Guiomar, Acre. We sampled three streams divided into three stretches each (100 m), bordered by forest, pasture, and both forest and pasture (edge). Quarterly collections using fishnets were performed between January and October 2008. Results The species A. agassizii had a diet based on the consumption of adult insects in stretches of forest, different from the pasture environment, in which the consumption of insect larvae was higher. In the diet of A. tetramerus, the most important item was insect larvae in all environments, mainly in the pasture. We found low amplitude of trophic niche for A. agassizii in the forest environment, due to the consumption of adult insects, and for A. tetramerus in the pasture, due to the consumption of insect larvae. In the pasture areas, we found no difference between the items consumed by the species, which showed a high trophic niche overlap, influenced by the consumption of Diptera larvae. Conclusion Thus, we show that allochthonous items, such as adult insects, are food resources indicative of riparian vegetation conservation and are important for both species, mainly A. agassizii. However, this item has been replaced by autochthonous items, such as Diptera larvae, in the A. agassizii diet and become predominant in the A. tetramerus diet as the riparian vegetation deteriorates.

Response of food resources and trophic niche of Apis cerana cerana to an altitudinal gradient in the north valley of the Lancang River

2017 ◽  
Vol 37 (9) ◽  
Author(s):  
陈顺安 CHEN Shun'an ◽  
张强 ZHANG Qiang ◽  
万蓉 WAN Rong ◽  
赵世文 ZHAO Shiwen ◽  
刘志涛 LIU Zhitao ◽  
...  
Keyword(s):  
Altitudinal Gradient ◽  
Apis Cerana ◽  
Food Resources ◽  
Trophic Niche ◽  
Apis Cerana Cerana ◽  
Lancang River ◽  
The North

Seasonal changes in home-range area and habitat use by the agile wallaby (Macropus agilis)

2003 ◽  
Vol 30 (6) ◽  
pp. 593 ◽  
Author(s):  
Simon C. Stirrat
Keyword(s):  
Home Range ◽  
Habitat Use ◽  
Home Range Size ◽  
Food Resources ◽  
Dry Season ◽  
Range Size ◽  
Home Ranges ◽  
Wet Season ◽  
Short Supply ◽  
Male And Female

Radio-tagged male and female agile wallabies were tracked in the wet and dry seasons at a site in Darwin, Northern Territory, and home ranges estimated using a kernel-based estimator. Home-range size (95% contour) was larger in the dry season, when food quality was poorer, and males had larger home ranges than females. Core range size (55% contour) did not differ between seasons or sexes. Average male and female home-range sizes in the wet season were 16.6 ha and 11.3 ha respectively. Wet-season core range sizes were 4.8 ha and 3.2 ha respectively. Average male and female home-range sizes in the dry season were 24.6 ha and 15.3 ha respectively, and dry-season core range sizes were 5.1 ha and 4.0 ha respectively. Home-range size for both sexes varied in the two seasons; the smallest and largest female home ranges were 6.3 ha and 24.0 ha respectively, while male home-range size varied from 7.6 ha to 38.2 ha. Seasonal differences in home-range size can be attributed to expansion of night-time foraging areas in the dry season when good-quality food resources were in short supply. Habitat use also differed between seasons. In the dry season more fixes were located in forest areas, particularly in the evening, when wallabies foraged in forest areas for alternate food resources including browse, leaf litter, flowers and fruits of rainforest tree and shrub species. In the wet season, wallabies emerged from day-time resting areas earlier in the afternoon and therefore more wallabies were located in open areas grazing on high-quality herbage in the evening.

scholarly journals Ecomorphology and use of food resources: inter- and intraspecific relationships of fish fauna associated with macrophyte stands

2016 ◽  
Vol 14 (4) ◽  
Author(s):  
Aline V. R. Prado ◽  
◽  
Erivelto Goulart ◽  
João P. A. Pagotto ◽  
◽  
...  
Keyword(s):  
Fish Species ◽  
Body Shape ◽  
Niche Breadth ◽  
Fish Fauna ◽  
Morphological Characteristics ◽  
Morphological Diversity ◽  
Food Resources ◽  
Trophic Niche ◽  
Eichhornia Azurea ◽  
The Relationship

ABSTRACT Based on the form-function interaction and its consequence to niche exploitation by fish species, the study aimed to identify ecomorphological patterns and to investigate the possibility of explaining the trophic niche breadth using the pattern of intraspecific ecomorphological diversity. We tested the following hypotheses: i) the morphology explains variations in diet among fish species; ii) the intraspecific ecomorphological diversity is related to the breadth of the trophic niche explored by the species, so that species that feed on a wider range of resources have greater variation in body shape compared to those specialized in resource consumption. Fish were collected in stands of the aquatic macrophytes Eichhornia azurea and Eichhornia crassipes in lentic environments of the Upper Paraná River floodplain, Brazil. Two major trends were observed in the morphological space: fish with body shapes adapted to explore the substrate and others with a design that facilitates the capture of food items in more structured habitats. The relationship of diet with body shape was confirmed by significant relationships between matrices of trophic and morphological distances, providing evidence that morphology is related to interspecific variations in the use of trophic resources. However, the ranges of morphological and intraspecific trophic variations were not significantly related, rejecting the second hypothesis about the relationship between intraspecific ecomorphological diversity and trophic niche breadth. The morphological characteristics often have multiple ecological roles, which could result in trade-off among these functions. Thus, fish with highly specialized morphology may show specialist feeding or even generalist habit, because in this case some resources may be difficult to exploit, even by a specialist. Species with low and high morphological diversity demonstrated narrow trophic niche and the availability of resources may have been essential for consumption. Therefore, species morphology is related to the use of food resources and ecomorphology can be considered an important tool for the prediction of the exploited niche space by species in assemblages. However it is not possible to predict if species with greater intraspecific morphological diversification indeed have wider niche, since the abundance or scarcity of the available food resources may interfere with trophic niche breadth.

scholarly journals Influence of group sizes and food resources in home-range sizes of capybaras from Argentina

2013 ◽  
Vol 94 (1) ◽  
pp. 19-28 ◽  
Author(s):  
Maria J. Corriale ◽  
Emiliano Muschetto ◽  
Emilio A. Herrera
Keyword(s):  
Home Range ◽  
Food Resources
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