scholarly journals Biogeographical patterns and diversity in the diet of the culpeo (Lycalopex culpaeus) in South America

2021 ◽  
Author(s):  
Jorge Lozano ◽  
Marta Guntiñas ◽  
Rodrigo Cisneros ◽  
Esther Llorente ◽  
Aurelio F. Malo
Keyword(s):  
Diversity Index ◽  
Information Criterion ◽  
Explanatory Models ◽  
Trophic Groups ◽  
Environmental Predictors ◽  
Large Herbivores ◽  
Trophic Diversity ◽  
Human Footprint ◽  
Carnivorous Species ◽  
Andean Fox

ABSTRACTHere we describe the dietary patterns of the culpeo (or Andean fox) at a biogeographical scale. We also analyze the influence of exotic lagomorphs on its diet and explore differences between culpeo subspecies. We selected 17 mutually comparable diet studies, which include 19 independent diet assessments. Then, we extracted and standardized the values of the different diet components from these studies and calculated the relative frequency of occurrence (RF) of the ten main trophic groups that we found. Further, we calculated the Shannon-Wienner H’ trophic diversity index.The results showed that small mammals (41%), lagomorphs (21%), invertebrates (12.4%) and large herbivores (7.3%) were the most consumed groups. A factorial analysis of all trophic groups rendered four orthogonal factors that were used as response variables in relation to a set of environmental predictors. Altitude correlated with most factors (i.e. trophic groups). Exotic lagomorphs were consumed in lowlands, in higher latitudes and in regions showing high values of the human footprint index, replacing in these areas native fauna as the main prey. There were no differences in diet between the two main culpeo subspecies analysed, L.c. culpaeus and L.c. andinus.Finally, the best explanatory models (GLM) of trophic diversity selected, using the Akaike’s information criterion (AIC), showed that the most diverse diets were those composed of large herbivores, edentates, carnivorous species, birds and herptiles (i.e. amphibians and reptils), in areas of high rainfall located in protected areas. Neither latitude nor altitude seemed to have an effect on the trophic diversity of the culpeos, as they were not retained by the final models.

scholarly journals Autoregressive modelling of species richness in the Brazilian Cerrado

2008 ◽  
Vol 68 (2) ◽  
pp. 233-240 ◽  
Author(s):  
CM. Vieira ◽  
D Blamires ◽  
JAF. Diniz-Filho ◽  
LM. Bini ◽  
TFLVB. Rangel
Keyword(s):  
Species Richness ◽  
Spatial Structure ◽  
Spatial Autocorrelation ◽  
Bird Species ◽  
Information Criterion ◽  
Type I ◽  
Environmental Predictors ◽  
Human Occupation ◽  
Ecological Data ◽  
Bird Species Richness

Spatial autocorrelation is the lack of independence between pairs of observations at given distances within a geographical space, a phenomenon commonly found in ecological data. Taking into account spatial autocorrelation when evaluating problems in geographical ecology, including gradients in species richness, is important to describe both the spatial structure in data and to correct the bias in Type I errors of standard statistical analyses. However, to effectively solve these problems it is necessary to establish the best way to incorporate the spatial structure to be used in the models. In this paper, we applied autoregressive models based on different types of connections and distances between 181 cells covering the Cerrado region of Central Brazil to study the spatial variation in mammal and bird species richness across the biome. Spatial structure was stronger for birds than for mammals, with R² values ranging from 0.77 to 0.94 for mammals and from 0.77 to 0.97 for birds, for models based on different definitions of spatial structures. According to the Akaike Information Criterion (AIC), the best autoregressive model was obtained by using the rook connection. In general, these results furnish guidelines for future modelling of species richness patterns in relation to environmental predictors and other variables expressing human occupation in the biome.

The Diets of Two Coexisting Species of Antechinus (Marsupialia: Dasyuridae).

1980 ◽  
Vol 7 (3) ◽  
pp. 365 ◽  
Author(s):  
S Hall
Keyword(s):  
Size Range ◽  
Prey Size ◽  
Diversity Index ◽  
Large Population ◽  
Stomach Contents ◽  
Trophic Diversity ◽  
Individual Variations ◽  
Faecal Samples ◽  
Antechinus Stuartii ◽  
Coexisting Species

An analysis of faecal samples and stomach contents of Antechinus stuartii and A. swainsonii inhabiting forest in southern Victoria revealed a large overlap in the type and size of prey items taken by these dasyurids. The frequencies of 23 prey types and 15 prey sizes in the diets of these predators were both positively correlated. Weevils (Coleoptera, Curculionidae) represented the only difference in prey types not attributed to individual variations. A. stuartii took more, and a wider size range of, weevils than did A. swainsonii; the trophic diversity index of prey types was greater for A. stuartii. The larger A. swainsonii took more prey greater than 20 mm; it took prey on the average 23% longer and 75% heavier than did A. stuartii; the trophic diversity index of prey size was greater for A. swainsonii. It is concluded that these morphologically distinct predators are exploiting the same large population of prey. They are both generalists and appear to be opportunistic feeders.

scholarly journals Zooplankton communities in three adjacent softwater lobelia lakes of slightly differentiated morphology and trophic state

2017 ◽  
Vol 17 (4) ◽  
pp. 207-214 ◽  
Author(s):  
Natalia Kuczyńska-Kippen ◽  
Piotr Klimaszyk ◽  
Ryszard Piotrowicz
Keyword(s):  
Species Diversity ◽  
Diversity Index ◽  
Ecological Status ◽  
Zooplankton Community ◽  
Taxonomic Structure ◽  
Environmental Predictors ◽  
Species Diversity Index ◽  
Zooplankton Community Structure ◽  
Lobelia Lakes ◽  
Zooplankton Communities

Abstract The paper presents the results of an investigation of physical-chemical features of water as well as rotifer and crustacean abundance and diversity measures, relating to the taxonomic richness and species diversity index, in three lobelia lakes differing in trophic status and morphometric features. The main purpose of this study was to establish the diversity of zooplankton communities in the open water area of lobelia lakes, including extracting species common for each lake and also to find environmental predictors which are responsible for the development of zooplankton communities. Despite the fact that the three studied lakes are of the same origin, located in the same vicinity and have generally similar environmental factors, zooplankton community structure revealed a great variation in reference to species diversity (only ca. 20% of the species were common for all lakes) and particularly in inhabiting species. Obrowo Lake had the most diverse assemblages of both rotifers and crustaceans compared to Modre and Pomysko lakes. In the taxonomic structure species that are rare for the Polish fauna, such as e.g. Holopedium gibberum and Heterocope appendiculata, occurred. Even though the examined lobelia lakes are ecosystems that undergo varying human-induced impacts, they still remain taxonomically very variable aquatic ecosystems, containing rare species of very high ecological status. The observed symptoms of deterioration of water quality, reflected in the zooplankton biocoenotic features, showed that the best conditions were attributed to Obrowo Lake in comparison with the two remaining lakes – Modre and Pomysko. Total nitrogen and chlorophyll a concentration were decisive for the distribution of zooplankton species in Pomysko and Obrowo lakes, while in case of Modre lake water reactivity and conductivity were of higher impact.

scholarly journals Food web diagnostics and functional diversity of soil inhabiting nematodes in a natural woodland

2009 ◽  
Vol 46 (3) ◽  
pp. 183-189 ◽  
Author(s):  
V. Tomar ◽  
W. Ahmad
Keyword(s):  
Food Web ◽  
Functional Diversity ◽  
Diversity Index ◽  
Maturity Index ◽  
Parasitic Nematodes ◽  
Positive Correlation ◽  
Trophic Diversity ◽  
Structure Index ◽  
The Stability ◽  
Plant Parasitic

AbstractFunctional diversity and detritus soil food web of soil inhabiting nematodes in natural woodland dominated by Acacia nilotica L. was studied. Functional diversity was studied in terms of trophic groups assessed by Trophic diversity index (TDI) and Shannon-Weaver index (H′), while food web was diagnosed by channel index (CI). The plant parasitic channel was determined by plant parasitic index (PPI). The stability of the soil ecosystem was measured in terms of maturity index (MI), structure index (SI) and enrichment index (EI). Shannon-Weaver index of the area was recorded as 2.1 ± 0.3 while trophic diversity index 2.6 ± 0.7, maturity index (MI) 3.1 ± 0.2, channel index 62.4 ± 28.1 and structure and enrichment indices 68.1 ± 18.5 and 15.4 ± 13.7 respectively. A high degree of positive correlation was recorded between population of dorylaims and MI while some degree of negative correlation existed between population of plant parasitic nematodes and MI. Population of other nematodes showed a positive correlation with SI and EI. The faunal profile was found to be tilted towards quadrat C giving the idea of relatively undisturbed ecosystem with moderate enrichment and fungal decomposition channel.

scholarly journals Feeding ecology of the culpeo in southern Ecuador: wild ungulates being the main prey

2017 ◽  
Vol 86 (2) ◽  
pp. 169-180 ◽  
Author(s):  
Marta Guntiñas ◽  
Jorge Lozano ◽  
Rodrigo Cisneros ◽  
Carlos Narváez ◽  
Jorge Armijos
Keyword(s):  
Temporal Variation ◽  
Small Mammals ◽  
Wild Ungulates ◽  
Diet Diversity ◽  
Wiener’S Index ◽  
Relative Contribution ◽  
Southern Ecuador ◽  
Carnivorous Species ◽  
First Time ◽  
Andean Fox

This study details for the first time the food habits of the culpeo or Andean fox (Lycalopex culpaeus) in high areas of the Ecuadorian Andes during a complete annual cycle. Our objective was to identify prey species, calculate their contribution to diet and test for temporal variation. In total, 304 Andean fox scats were collected within the Podocarpus National Park (Loja province, southern Ecuador). By analysing the content of scats 413 prey items were identified and classified into eight prey groups. Sub-sequently, the frequency of occurrence (FO) for each prey group was calculated per month together with the relative contribution of estimated consumed biomass (CB). In addition, the Shannon-Wiener’s index was calculated as a measurement of monthly diet diversity. The results show a diet dominated by cervids belonging to the Mazama and Pudu genus (70% FO), followed by small mammals (30% FO), large rodents (12% FO), carnivorous species (10% FO) and lagomorphs (8% FO). There was temporal variation in the consumption of both deer and small mammals. Cervids also provided the major part of the consumed biomass (70% CB), the remaining prey categories each accounted for less than 11% CB. Negative correlations in consumption were observed between cervids and two other groups, rabbits and small mammals. Trophic diversity values fluctuated throughout the year showing a mean of 1.7. The results obtained show a diets very different from those previously reported; deer being the bulk of the diet instead of rodents or other mammals. The consumption of carnivorous species in the area was also high in comparison with other regions. Overall, this study clearly demonstrates that the culpeo is an important top predator in the high-Andean ecosystem.

A trophic diversity index for presence-absence food data

Oecologia ◽  
1976 ◽  
Vol 25 (2) ◽  
pp. 187-191 ◽  
Author(s):  
Carlos M. Herrera
Keyword(s):  
Diversity Index ◽  
Trophic Diversity

Benthic mollusc assemblages in West Antarctica: taxa composition and ecological insights

2017 ◽  
Vol 68 (11) ◽  
pp. 2095 ◽  
Author(s):  
Sandra Gordillo ◽  
Mariano E. Malvé ◽  
Gisela Moran
Keyword(s):  
Diversity Index ◽  
Benthic Communities ◽  
Austral Summer ◽  
Trophic Groups ◽  
West Antarctica ◽  
Suspension Feeders ◽  
Deposit Feeders ◽  
Wiener Diversity Index ◽  
Mollusc Assemblages ◽  
Group Species

Although different studies in Antarctica have dealt with benthic communities, few studies have focused on molluscan assemblages and their ecology. During the austral summer of 2011, 17 stations between depths of 68.5 and 754m were sampled in West Antarctica using a demersal bottom trawl pilot net on board RV ARA Puerto Deseado. In all, 1848 specimens of shelled molluscs were recorded. Gastropods were the most diverse group (species richness=74) and bivalves were the most abundant (n=1344). Shannon–Wiener diversity index values ranged between 0.58 and 2.99, with great variation at different stations. Cluster analysis using the Bray–Curtis coefficient showed three distinct assemblages types: one dominated by suspension feeders; a second with representatives from different trophic groups, including suspension feeders, grazers, scavengers, predators and deposit feeders; and a third, more differentiated, with few taxa and dominated by deposit feeders. Finally, multivariate analysis suggests that bivalves were more sensitive to temperature, whereas gastropods were more sensitive to depth.

scholarly journals Spatial and genetic structure of the lodgepole × jack pine hybrid zone

2019 ◽  
Vol 49 (7) ◽  
pp. 844-853 ◽  
Author(s):  
Ian Burns ◽  
Patrick M.A. James ◽  
David W. Coltman ◽  
Catherine I. Cullingham
Keyword(s):  
Hybrid Zone ◽  
Pinus Banksiana ◽  
Pinus Contorta ◽  
Mountain Pine Beetle ◽  
Lodgepole Pine ◽  
Information Criterion ◽  
Jack Pine ◽  
Snp Markers ◽  
Environmental Predictors ◽  
Essential Information

In north-central Alberta, lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia) and jack pine (Pinus banksiana Lamb.) form a mosaic hybrid zone, the spatial extent of which remains poorly defined. We sought to refine the genetic and geographic distribution of this hybrid zone in western North America to provide information important in predicting future risk of mountain pine beetle (Dendroctonus ponderosae Hopkins) outbreaks. We used 29 single nucleotide polymorphism (SNP) markers to discriminate lodgepole pine, jack pine, and their hybrids. We compared and contrasted spatial patterns of hybridization in northern and southern forest zones based on the colonization history of the two species. We found that patterns of introgression were more similar between the zones than expected by chance, but there were significant differences between these regions at specific loci. Using logistic regression, we created a robust predictive model to distinguish among lodgepole pine, jack pine, and their hybrids using a combination of geographic and environmental predictors. Using model selection based on Akaike information criterion, we found that location, elevation, and moisture are important predictors for species class. Quantification of the genetic differences between these two regions, combined with an accurate model for predicting the spatial distribution of lodgepole pine, jack pine, and their hybrids, provides essential information for continued effective management of forest resources.

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