scholarly journals Predation Risk is a Function of Seasonality Rather than Habitat Complexity in a Tropical Semi-arid Forest

2021 ◽  
Author(s):  
Anthony Ferreira ◽  
Renato Faria
Keyword(s):  
Predation Risk ◽  
Species Interactions ◽  
Structural Complexity ◽  
The Body ◽  
Northeastern Brazil ◽  
Arid Environments ◽  
Ecological Processes ◽  
Important Species ◽  
Predator Prey ◽  
Semi Arid

Abstract Predator-prey dynamic is one of the most important species’ interactions in the natural structuring of communities, and is among the more complex ecological processes studied by ecologists. We measure predation risk using artificial lizard replicas to test two competing hypotheses regarding predation pressure in semi-arid environments: (1) predation risk is dependent on the habitat structural complexity; and (2) predation risk is dependent on seasonality. We placed 960 replicas along three sites with different physical structures and in both seasons for seven consecutive days in a caatinga area in northeastern Brazil. Birds were responsible for the majority of attacks and more frequently on artificial lizards placed in trees. Attacks focused on the most vulnerable areas of the body (head and torso), proving that were perceived by predators as true prey items. We found that predation risk is not dependent on the habitat structural complexity, but rather dependent on the caatinga seasonality, with the overall attack being 19% higher in the dry season. Our study suggests that potential predation risk is highly context-dependent and that seasonality consistently drives of trophic interactions strength in the caatinga, an important ecological finding that could contribute to better understanding the complex evolution of predator-prey interactions within communities of animals living in different habitats.

scholarly journals Predation risk is a function of seasonality rather than habitat complexity in a tropical semiarid forest

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anthony Santana Ferreira ◽  
Renato Gomes Faria
Keyword(s):  
Predation Risk ◽  
Species Interactions ◽  
Structural Complexity ◽  
The Body ◽  
Northeastern Brazil ◽  
Arid Environments ◽  
Ecological Processes ◽  
Important Species ◽  
Predator Prey ◽  
Natural Monument

AbstractPredator–prey dynamics are some of the most important species’ interactions in the natural structuring of communities, and are among the more complex ecological processes studied by ecologists. We measured predation risk using artificial lizard replicas to test two competing hypotheses regarding predation pressure in semi-arid environments: (1) predation risk is dependent on the habitat structural complexity; and (2) predation risk is dependent on seasonality. We placed 960 lizard replicas along three sites with different physical structures and in both dry and rainy seasons for seven consecutive days in a caatinga area in northeastern Brazil at Grota do Angico Natural Monument (GANM). Birds were responsible for the majority of attacks and more frequently on artificial lizards placed in trees. Attacks focused on the most vulnerable areas of the body (head and torso), proving that were perceived by predators as true prey items. We found that predation risk is not dependent on the habitat structural complexity, but rather dependent on the caatinga seasonality, with the overall attack rate being 19% higher in the dry season. Our study suggests that potential predation risk is highly context-dependent and that seasonality consistently drives of trophic interactions strength in the caatinga, an important ecological finding that could contribute to better understanding the complex evolution of predator–prey interactions within communities of animals living in different habitats.

scholarly journals Ethnobotany in Intermedical Spaces: The Case of the Fulni-ô Indians (Northeastern Brazil)

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Gustavo Taboada Soldati ◽  
Ulysses Paulino de Albuquerque
Keyword(s):  
Secondary Data ◽  
Medical System ◽  
The Body ◽  
Northeastern Brazil ◽  
Important Species ◽  
Cultural Sustainability ◽  
Botanical Knowledge ◽  
Therapeutic Uses ◽  
Local Practices ◽  
Traditional Botanical Knowledge

We analyzed the Fulni-ô medical system and introduced its intermedical character based on secondary data published in the literature. Then we focused on the medicinal plants known to the ethnic group, describing the most important species, their therapeutic uses and the body systems attributed to them. We based this analysis on the field experience of the authors in the project Studies for the Environmental and Cultural Sustainability of the Fulni-ô Medical System: Office of Medicinal Plant Care. This traditional botanical knowledge was used to corroborate the hybrid nature of local practices for access to health. We show that intermedicality is a result not only of the meeting of the Fulni-ô medical system with Biomedicine but also of its meeting with other traditional systems. Finally, we discuss how traditional botanical knowledge may be directly related to the ethnogenesis process led by the Fulni-ô Indians in northeastern Brazil.

scholarly journals Using 3D micro-geomorphometry to quantify interstitial spaces of an oyster cluster

2019 ◽  
Author(s):  
Kwanmok Kim ◽  
Vincent Lecours ◽  
Peter C. Frederick
Keyword(s):  
Species Interactions ◽  
Point Cloud ◽  
Structural Complexity ◽  
Ecological Studies ◽  
Empirical Relationships ◽  
Predator Prey ◽  
Interstitial Volume ◽  
Curvature Measures ◽  
Technological Limitations

In ecology, it is assumed that the characteristics (e.g. shape, size) of interstitial spaces found in a variety of habitats affect the colonization of species, species interactions, and species composition. However, those characteristics have traditionally been difficult to measure due to technological limitations. In this study, we used the Structure-from-Motion (SfM) photogrammetry technique to measure the physical characteristics of interstitial spaces in a small oyster cluster. The point cloud (and mesh) of the oyster cluster derived from SfM photogrammetry was found to be accurate enough (mean error of 0.654 mm) to conduct 3D geomorphometric analyses. We present an example of measures of curvature, roughness, interstitial volume, surface area, and openness for three 3D interstitial spaces. The interpretation of those measures enabled establishing which interstitial spaces were the most likely to be used as a shelter for an average crab. Those spaces are characterized by smaller openness and higher roughness and curvature measures. This initial quantitative 3D characterization of an oyster cluster is the first step in establishing empirical relationships between structural complexity of biological structures like oyster clusters and their ecological role for instance in predator-prey interactions. Overall, this study demonstrates the feasibility of combining SfM photogrammetry with geomorphometry for fine-scale ecological studies.

Resource pulses, species interactions, and diversity maintenance in arid and semi-arid environments

Oecologia ◽  
2004 ◽  
Vol 141 (2) ◽  
pp. 236-253 ◽  
Author(s):  
Peter Chesson ◽  
Renate L. E. Gebauer ◽  
Susan Schwinning ◽  
Nancy Huntly ◽  
Kerstin Wiegand ◽  
...  
Keyword(s):  
Species Interactions ◽  
Arid Environments ◽  
Resource Pulses ◽  
Diversity Maintenance ◽  
Semi Arid

Training barn owls: a powerful tool in ecological experiments

2016 ◽  
Vol 62 (3-4) ◽  
pp. 149-154
Author(s):  
Aziz Subach
Keyword(s):  
Predation Risk ◽  
Body Mass ◽  
Field Experiments ◽  
Empirical Studies ◽  
The Body ◽  
Training Procedure ◽  
Predator Prey ◽  
Ecological Experiments ◽  
Barn Owls ◽  
Rodent Prey

Predators affect prey directly by predation and indirectly by triggering behavioral responses that aim at reducing predation risk. In this paper, I present a method for training an avian predator which can allow separating between its direct and indirect effects on prey in various experimental setups. Barn owls are found to be a valuable tool for empirically testing different hypotheses related to predator-prey interactions, population dynamics, and inter-specific competition, all performed in the field using authentic rodent prey and their natural predators. Barn owls are raised and trained to participate in field experiments using classical conditioning, and are trained either to catch rodents or only to fly above a certain area without making any attempt to attack the prey, simulating solely predation risk. Body mass is a crucial factor in the training procedure, and I thus define five body mass ranges that characterize different behavioral stages in the training of owls. A logistic model is used to calculate and to predict changes in the body mass during the growth and training periods of owls. Finally, I discuss several possible implications of the usage of trained barn owls in empirical studies.

scholarly journals Species interactions and spatial heterogeneity: predicting cascading predator effects on landscape biogeochemistry

2020 ◽  
Author(s):  
Julia D. Monk ◽  
A. Carla Staver ◽  
Oswald J. Schmitz
Keyword(s):  
Spatial Heterogeneity ◽  
Predation Risk ◽  
Species Interactions ◽  
Animal Movement ◽  
Landscape Heterogeneity ◽  
Ecological Systems ◽  
General Will ◽  
Positive Feedbacks ◽  
Predator Prey ◽  
Risk Effects

Spatial heterogeneity in ecological systems can result from top-down processes, but despite some theoretical attention, the emergence of spatial heterogeneity from feedbacks with consumers is not well understood empirically. Interactions between predators and prey influence animal movement and associated nutrient transport and release, generating spatial heterogeneity that cascades throughout ecological systems. In this review, we synthesize the existing literature to evaluate the mechanisms by which terrestrial predators can generate spatial heterogeneity in biogeochemical processes through consumptive and non-consumptive effects. Overall, we propose that predators increase heterogeneity in ecosystems whenever predation is intense and spatially variable, whereas predator-prey interactions homogenize ecosystems whenever predation is weak or diffuse in space. This leads to several testable hypotheses: (1) that predation and carcass deposition at high-predation risk sites stimulate positive feedbacks between predation risk and nutrient availability; (2) that prey generate nutrient hotspots when they concentrate activity in safe habitats, but instead generate nutrient subsidies when they migrate daily between safe and risky habitats; (3) that herbivore body size mediates risk effects, such that megaherbivores are more likely to homogenize ecosystems; and 4) that predator loss in general will tend to homogenize ecosystems. Testing these hypotheses will advance our understanding of whether predators amplify landscape heterogeneity in ecological systems.

scholarly journals Predation models for primary and secondary prey species

1995 ◽  
Vol 22 (1) ◽  
pp. 55 ◽  
Author(s):  
R. P. Pech ◽  
A. R. E. Sinclair ◽  
A. E. Newsome
Keyword(s):  
Native Species ◽  
Prey Species ◽  
Red Fox ◽  
Experimental Tests ◽  
Generalist Predator ◽  
Arid Environments ◽  
Predator Prey ◽  
European Rabbits ◽  
Predator Prey Models ◽  
Semi Arid

In Australia, the red fox (Vulpes vulpes) is a generalist predator of European rabbits (Oryctolagus cuniculus) and a range of small to medium-sized native species. The available evidence suggests that foxes are capable of regulating rabbits in semi-arid environments but their role in the population dynamics of other prey species is not clear. A series of models, and associated experimental tests, that compare the effects of predation on primary and secondary prey species are described. The models are appropriate to the time scale of prey dynamics and differ from recent predator–prey models that focus on predator dynamics. These ideas are discussed for the fox and several of its prey species in Australia.

scholarly journals Using 3D micro-geomorphometry to quantify interstitial spaces of an oyster cluster

2019 ◽  
Author(s):  
Kwanmok Kim ◽  
Vincent Lecours ◽  
Peter C. Frederick
Keyword(s):  
Species Interactions ◽  
Point Cloud ◽  
Structural Complexity ◽  
Ecological Studies ◽  
Empirical Relationships ◽  
Predator Prey ◽  
Interstitial Volume ◽  
Curvature Measures ◽  
Technological Limitations

In ecology, it is assumed that the characteristics (e.g. shape, size) of interstitial spaces found in a variety of habitats affect the colonization of species, species interactions, and species composition. However, those characteristics have traditionally been difficult to measure due to technological limitations. In this study, we used the Structure-from-Motion (SfM) photogrammetry technique to measure the physical characteristics of interstitial spaces in a small oyster cluster. The point cloud (and mesh) of the oyster cluster derived from SfM photogrammetry was found to be accurate enough (mean error of 0.654 mm) to conduct 3D geomorphometric analyses. We present an example of measures of curvature, roughness, interstitial volume, surface area, and openness for three 3D interstitial spaces. The interpretation of those measures enabled establishing which interstitial spaces were the most likely to be used as a shelter for an average crab. Those spaces are characterized by smaller openness and higher roughness and curvature measures. This initial quantitative 3D characterization of an oyster cluster is the first step in establishing empirical relationships between structural complexity of biological structures like oyster clusters and their ecological role for instance in predator-prey interactions. Overall, this study demonstrates the feasibility of combining SfM photogrammetry with geomorphometry for fine-scale ecological studies.

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