scholarly journals Ontogenetic variation in the diet of the anuran community from a semi-arid environment in the southeastern Chihuahuan Desert

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7908
Author(s):  
Ricardo Luría-Manzano ◽  
Aurelio Ramírez-Bautista
Keyword(s):  
Arid Environment ◽  
Sympatric Species ◽  
Trophic Niche ◽  
Niche Width ◽  
Ontogenetic Variation ◽  
Dietary Composition ◽  
Ontogenetic Changes ◽  
Species Identity ◽  
Predator Size ◽  
Semi Arid

Although ontogeny influences dietary composition and trophic niche breadth in many anurans, its effects on diet have been little analyzed in sympatric species. In this study, we analyzed interspecific and ontogenetic variation in dietary composition and trophic niche width in an anuran community from a semi-arid environment. We found a more profound effect of species identity than body size on dietary composition, with the diet of four species dominated by formicids, that of two others by coleopterans and formicids, and that of the remaining species not dominated by specific prey types. We found ontogenetic changes in dietary composition in three of four species analyzed, in which consumption of some small insects decreased as predator size increased, regardless of species. Additionally, we did not find ontogenetic change in prey number consumed in any of the four species, but prey size increased with increasing predator size in all of them. Most species exhibited a narrow trophic niche, which was even narrower in adults in three of the four species analyzed. Costello’s modified plots revealed a high variation among individuals in termite consumption in Anaxyrus punctatus, and in more prey types in Spea multiplicata. Our results suggest that this community is not size-structured, and that ontogenetic diet shifts are mainly caused by passive sampling toward prey of different sizes. Finally, comparisons with previous data revealed an interpopulation pattern, in which trophic niche width contracts as aridity increases, possibly because of an increase in interspecific competition for trophic resources.

scholarly journals Feeding ecology of Eigenmannia desantanai (Gymnotiformes: Sternopygidae) in southern Pantanal, Brazil

2022 ◽  
Vol 34 ◽  
Author(s):  
Élida Jeronimo Gouveia ◽  
Patrícia Luna Rondon ◽  
Yzel Rondon Súarez
Keyword(s):  
Feeding Ecology ◽  
Niche Breadth ◽  
Trophic Niche ◽  
Ontogenetic Variation ◽  
Dietary Composition ◽  
Food Items ◽  
Paraguay River ◽  
Explained Variation ◽  
Management And Conservation

Abstract Aim This study investigated changes in the dietary composition and trophic niche breadth of Eigenmannia desantanai in the context of hydrological periods, rivers, and ontogeny. Methods Collections were performed monthly on the Paraguay and Amonguijá Rivers between February 2009 and January 2011. Results A total of 338 specimens of E. desantanai were collected, 224 of which came from the Amonguijá River and 114 from the Paraguay River. In all, 21 food items were identified. Fully remains of digested animals (RDA), Chironomidae, Cladocera, and Ostracoda showed greater importance in the diet of E. desantanai. Dietary composition was influenced by hydrological periods, followed by differences between sampled rivers, and ontogeny. In contrast, only hydrological periods explained variation in the E. desantanai trophic niche breadth. Conclusions The diet of E. desantanai is mainly composed of Chironomidae, Cladocera, and Ostracoda; however, individuals consumed other food items owing to changes in hydrological periods, followed by characteristics of the Amonguijá and Paraguay Rivers and ontogenetic variation. In this respect, the results of this study are germane to the food ecology of E. desantanai, providing guidelines for the management and conservation of the species.

Spatial trophic variability of a coastal apex predator, the giant trevally Caranx ignobilis, in the western Indian Ocean

2020 ◽  
Vol 641 ◽  
pp. 195-208
Author(s):  
JR Glass ◽  
R Daly ◽  
PD Cowley ◽  
DM Post
Keyword(s):  
Indian Ocean ◽  
Trophic Ecology ◽  
Niche Breadth ◽  
Trophic Position ◽  
Western Indian Ocean ◽  
Trophic Niche ◽  
Niche Width ◽  
Apex Predator ◽  
Ontogenetic Changes ◽  
Top Predators

Top predators have substantial downstream effects on the structure, function, and resilience of ecosystems. The influence of top predators on an ecosystem can vary if they occur within multiple habitat types and have a wide niche breadth due to spatiotemporal changes in diet. We examined spatial patterns in trophic position and niche width for an economically important reef-associated fishery species, the giant trevally Caranx ignobilis. We sampled 4 localities in the western Indian Ocean representing different habitats: coral atolls, coastal reefs, and granitic islands. We analyzed isotopic ratios of carbon (13C/12C) and nitrogen (15N/14N), and performed compound-specific amino acid stable isotope analysis (AA-CSIA) to control for baseline nitrogen variation. Our analysis of 12 juveniles and 43 adults revealed wide variation in trophic niche breadth between sampling sites and an offshore to coastal gradient in carbon that drove niche distinctiveness between localities. We observed niche width patterns suggestive of ontogenetic changes in diet and habitat utilization and larger niche sizes at the oceanic island sites than the coastal site. Trophic position estimates ranged from 3.5-5, expanding the trophic range of C. ignobilis relative to previous studies using AA-CSIA and placing it at the equivalent trophic level as many predatory sharks. Our study corroborates prior evidence that C. ignobilis is an important apex predator in reef and island ecosystems. Additionally, we show how evaluating spatiotemporal components of trophic ecology of marine predators is critical for characterizing their functional role and ecosystem influence, allowing for targeted conservation efforts.

CASE STUDY: Evaluation of Different Cooling Systems in Lactating Heat-Stressed Dairy Cows in a Semi-Arid Environment

2007 ◽  
Vol 23 (5) ◽  
pp. 546-555 ◽  
Author(s):  
R. Burgos ◽  
L.J. Odens ◽  
R.J. Collier ◽  
L.H. Baumgard ◽  
M.J. VanBaale
Keyword(s):  
Dairy Cows ◽  
Arid Environment ◽  
Cooling Systems ◽  
Study Evaluation ◽  
Semi Arid

Morphology and diet of two sympatric colubrid snakes, Chironius flavolineatus and Chironius quadricarinatus (Serpentes: Colubridae)

2008 ◽  
Vol 29 (2) ◽  
pp. 149-160 ◽  
Author(s):  
Otavio Augusto Vuolo Marques ◽  
Ronaldo Fernandes ◽  
Roberta Richard Pinto
Keyword(s):  
Foraging Behaviour ◽  
Sexual Size Dimorphism ◽  
Sympatric Species ◽  
Colour Pattern ◽  
Ontogenetic Variation ◽  
Brazilian Cerrado ◽  
Size Dimorphism ◽  
Snake Species ◽  
Dietary Ecology ◽  
Arboreal Habit

Abstract The morphometry and diet of two sympatric species of Chironius (C. flavolineatus and C. quadricarinatus) from Brazilian Cerrado are described. The two snake species differ in external morphology, as Chironius flavolineatus was the largest species (body, tail and eyes) whereas C. quadricarinatus the heaviest. Each species also showed marked sexual size dimorphism. In terms of dietary ecology, both species feed exclusively on frogs with a heavy preference for hylids and may have tendency to eat small items, as noticed in other colubrine species. These two snake species showed a brownish colour pattern and exhibited no ontogenetic variation, suggesting that juveniles and adults use similar substrates. Chironius flavolineatus and C. quadricarinatus present a semi-arboreal habit, with active foraging behaviour, feeding in the ground most of time. Chironius flavolineatus uses higher vegetation for resting and, based on morphological results, seems to be more arboreal than C. quadricarinatus.

scholarly journals Predicting the past, present and future distributions of an endangered marsupial in a semi‐arid environment

2021 ◽  
Author(s):  
J. Riley ◽  
M.R.K. Zeale ◽  
O. Razgour ◽  
J. Turpin ◽  
G. Jones
Keyword(s):  
Arid Environment ◽  
The Past ◽  
Semi Arid

scholarly journals Climatic Zone and Soil Properties Determine the Biodiversity of the Soil Bacterial Communities Associated to Native Plants from Desert Areas of North-Central Algeria

2021 ◽  
Vol 9 (7) ◽  
pp. 1359
Author(s):  
Elisa Bona ◽  
Nadia Massa ◽  
Omrane Toumatia ◽  
Giorgia Novello ◽  
Patrizia Cesaro ◽  
...  
Keyword(s):  
Soil Properties ◽  
Bacterial Communities ◽  
Arid Environment ◽  
Climatic Zone ◽  
Indigenous Plants ◽  
North Central ◽  
The North ◽  
Desert Areas ◽  
Plant Microbiota ◽  
Semi Arid

Algeria is the largest country in Africa characterized by semi-arid and arid sites, located in the North, and hypersaline zones in the center and South of the country. Several autochthonous plants are well known as medicinal plants, having in common tolerance to aridity, drought and salinity. In their natural environment, they live with a great amount of microbial species that altogether are indicated as plant microbiota, while the plants are now viewed as a “holobiont”. In this work, the microbiota of the soil associated to the roots of fourteen economically relevant autochthonous plants from Algeria have been characterized by an innovative metagenomic approach with a dual purpose: (i) to deepen the knowledge of the arid and semi-arid environment and (ii) to characterize the composition of bacterial communities associated with indigenous plants with a strong economic/commercial interest, in order to make possible the improvement of their cultivation. The results presented in this work highlighted specific signatures which are mainly determined by climatic zone and soil properties more than by the plant species.

Modelling groundwater evapotranspiration in a shallow aquifer in a semi-arid environment

2020 ◽  
Vol 587 ◽  
pp. 124967
Author(s):  
Ousmane Coly Diouf ◽  
Lutz Weihermüller ◽  
Mathias Diedhiou ◽  
Harry Vereecken ◽  
Seynabou Cissé Faye ◽  
...  
Keyword(s):  
Arid Environment ◽  
Shallow Aquifer ◽  
Groundwater Evapotranspiration ◽  
Semi Arid
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