scholarly journals Artificial night light alters nocturnal prey interception outcomes for morphologically variable spiders

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e4070 ◽  
Author(s):  
Suet Wai Yuen ◽  
Timothy C. Bonebrake
Keyword(s):  
Morphological Variation ◽  
Species Interactions ◽  
Floral Resources ◽  
Color Contrast ◽  
Color Patterns ◽  
Predator Prey ◽  
Yellow Color ◽  
Set Up ◽  
Prey Attraction

Artificial night light has the potential to significantly alter visually-dependent species interactions. However, examples of disruptions of species interactions through changes in light remain rare and how artificial night light may alter predator–prey relationships are particularly understudied. In this study, we examined whether artificial night light could impact prey attraction and interception inNephila pilipesorb weaver spiders, conspicuous predators who make use of yellow color patterns to mimic floral resources and attract prey to their webs. We measured moth prey attraction and interception responses to treatments where we experimentally manipulated the color/contrast of spider individuals in the field (removed yellow markings) and also set up light manipulations. We found that lit webs had lower rates of moth interception than unlit webs. Spider color, however, had no clear impact on moth interception or attraction rates in lit nor unlit webs. The results show that night light can reduce prey interception for spiders. Additionally, this study highlights how environmental and morphological variation can complicate simple predictions of ecological light pollution’s disruption of species interactions.

scholarly journals Impacts of predator-mediated interactions along a climatic gradient on the population dynamics of an alpine bird

2020 ◽  
Author(s):  
Diana E. Bowler ◽  
Mikkel A. J. Kvasnes ◽  
Hans C. Pedersen ◽  
Brett K. Sandercock ◽  
Erlend B. Nilsen
Keyword(s):  
Population Dynamics ◽  
Species Interactions ◽  
Climatic Conditions ◽  
Boreal Ecosystems ◽  
Prey Switching ◽  
Predator Prey ◽  
Classic Theory ◽  
Species Population ◽  
Cyclic Dynamics ◽  
Ground Nesting

AbstractAccording to classic theory, species’ population dynamics and distributions are less influenced by species interactions under harsh climatic conditions compared to under more benign climatic conditions. In alpine and boreal ecosystems in Fennoscandia, the cyclic dynamics of rodents strongly affect many other species, including ground-nesting birds such as ptarmigan. According to the ‘alternative prey hypothesis’ (APH), the densities of ground-nesting birds and rodents are positively associated due to predator-prey dynamics and prey-switching. However, it remains unclear how the strength of these predator-mediated interactions change along a climatic harshness gradient in comparison with the effects of climatic variation. We built a hierarchical Bayesian model to estimate the sensitivity of ptarmigan populations to interannual variation in climate and rodent occurrence across Norway during 2007–2017. Ptarmigan abundance was positively linked with rodent occurrence, consistent with the APH. Moreover, we found that rodent dynamics had stronger effects on ptarmigan in colder regions. Our study highlights how species interactions play an important role for the population dynamics of species at higher latitudes and suggests that they can become even more important in the most climatically harsh regions.

scholarly journals Multispecies integrated population model reveals bottom-up dynamics in a seabird predator-prey system

2020 ◽  
Author(s):  
Maud Quéroué ◽  
Christophe Barbraud ◽  
Frédéric Barraquand ◽  
Daniel Turek ◽  
Karine Delord ◽  
...  
Keyword(s):  
Breeding Success ◽  
Species Interactions ◽  
Interspecific Interactions ◽  
Demographic Parameters ◽  
Multiple Sources ◽  
Bottom Up ◽  
Climate Conditions ◽  
Predator Prey ◽  
Relative Contribution ◽  
Prey System

AbstractAssessing the effects of climate and interspecific relationships on communities is challenging because of the complex interplay between species population dynamics, their interactions, and the need to integrate information across several biological levels (individuals – populations – communities). Usually used to quantify species interactions, integrated population models (IPMs) have recently been extended to communities. These models allow fitting multispecies matrix models to data from multiple sources while simultaneously accounting for various sources of uncertainty in each data source. We used multispecies IPMs accommodating climate conditions to quantify the relative contribution of climate vs. interspecific interactions on demographic parameters, such as survival and breeding success, in the dynamics of a predator-prey system. We considered a stage-structured predator–prey system combining 22 years of capture–recapture data and population counts of two seabirds, the Brown Skua (Catharacta lönnbergi) and its main prey the Blue Petrel (Halobaena caerulea) both breeding on the Kerguelen Islands in the Southern Ocean. Our results showed that climate and predator-prey interactions drive the demography of skuas and petrels in different ways. The breeding success of skuas appeared to be largely driven by the number of petrels and to a lesser extent by intraspecific density-dependence. In contrast, there was no evidence of predation effects on the demographic parameters of petrels, which were affected by oceanographic factors (chlorophyll a and sea surface temperature anomalies). We conclude that bottom-up mechanisms are the main drivers of this skua-petrel system. We discuss the mechanisms by which climate variability and predator-prey relationships may affect the demographic parameters of these seabirds. Taking into account both species interactions and environmental covariates in the same analysis improved our understanding of species dynamics.

Predator–prey interactions and climate change

2019 ◽  
pp. 199-220 ◽  
Author(s):  
Vincent Bretagnolle ◽  
Julien Terraube
Keyword(s):  
Climate Change ◽  
Species Interactions ◽  
Experimental Studies ◽  
Trophic Levels ◽  
Generalist Predators ◽  
Top Down ◽  
Predator Prey ◽  
Key Topics ◽  
Available Information

Climate change is likely to impact all trophic levels, although the response of communities and ecosystems to it has only recently received considerable attention. Further, it is expected to affect the magnitude of species interactions themselves. In this chapter, we summarize why and how climate change could affect predator–prey interactions, then review the literature about its impact on predator–prey relationships in birds, and provide prospects for future studies. Expected effects on prey or predators may include changes in the following: distribution, phenology, population density, behaviour, morphology, or physiology. We review the currently available information concerning particular key topics: top-down versus bottom-up control, specialist versus generalist predators, functional versus numerical responses, trophic cascades and regime shifts, and lastly adaptation and selection. Finally, we focus our review on two well-studied bird examples: seabirds and raptors. Key future topics include long-term studies, modelling and experimental studies, evolutionary questions, and conservation issues.

scholarly journals Diversity and coexistence are influenced by time‐dependent species interactions in a predator–prey system

2020 ◽  
Vol 23 (6) ◽  
pp. 983-993 ◽  
Author(s):  
Canan Karakoç ◽  
Adam Thomas Clark ◽  
Antonis Chatzinotas
Keyword(s):  
Species Interactions ◽  
Time Dependent ◽  
Predator Prey ◽  
Prey System

Measuring Perceptual Distance of Organismal Color Pattern using the Features of Deep Neural Networks

2019 ◽  
Author(s):  
Drew C. Wham ◽  
Briana Ezray ◽  
Heather M. Hines
Keyword(s):  
Deep Neural Networks ◽  
Color Pattern ◽  
Color Contrast ◽  
Biological Processes ◽  
Color Patterns ◽  
Biologically Relevant ◽  
Perceptual Distance ◽  
Data Formats ◽  
Wide Range ◽  
Study Designs

ABSTRACTA wide range of research relies upon the accurate and repeatable measurement of the degree to which organisms resemble one another. Here, we present an unsupervised workflow for analyzing the relationships between organismal color patterns. This workflow utilizes several recent advancements in deep learning based computer vision techniques to calculate perceptual distance. We validate this approach using previously published datasets surrounding diverse applications of color pattern analysis including mimicry, population differentiation, heritability, and development. We demonstrate that our approach is able to reproduce the biologically relevant color pattern relationships originally reported in these studies. Importantly, these results are achieved without any task-specific training. In many cases, we were able to reproduce findings directly from original photographs or plates with minimum standardization, avoiding the need for intermediate representations such as a cartoonized images or trait matrices. We then present two artificial datasets designed to highlight how this approach handles aspects of color patterns, such as changes in pattern location and the perception of color contrast. These results suggest that this approach will generalize well to support the study of a wide range of biological processes in a diverse set of taxa while also accommodating a variety of data formats, preprocessing techniques, and study designs.

scholarly journals Consumption of Atlantic Salmon Smolt by Striped Bass: A Review of the Predator–Prey Encounter and Implications for the Design of Effective Sampling Strategies

Fishes ◽  
2019 ◽  
Vol 4 (4) ◽  
pp. 50
Author(s):  
Andrews ◽  
Hirtle ◽  
Linnansaari ◽  
Curry
Keyword(s):  
Atlantic Salmon ◽  
Striped Bass ◽  
Species Interactions ◽  
Morone Saxatilis ◽  
Sampling Strategies ◽  
Native Range ◽  
Spawning Period ◽  
Predator Prey ◽  
Salmon Smolt ◽  
Future Management

The native striped bass (Morone saxatilis) population of the Miramichi River, New Brunswick is undergoing an unprecedented recovery while Atlantic salmon (Salmo salar) numbers within that system continue to decline. Atlantic salmon smolt depart from the Miramichi system during the striped bass spawning period and it is hypothesized that elevated striped bass abundances will increase encounter rates and predation on smolts. We summarize all available striped bass diet studies occurring within the native range of Atlantic salmon and present a review of the feeding behavior and diet preferences of striped bass before, during, and after their spawning period. The key studies vary in methodologies and interpretability. We present a standardized approach for assessing striped bass predation threats and smolt vulnerability and thus an improved understanding of the species interactions to guide future management in the Miramichi River.

Evaluating the influence of predator–prey interactions on stock assessment and management reference points for a large lake ecosystem

2016 ◽  
Vol 73 (9) ◽  
pp. 1372-1388 ◽  
Author(s):  
Hiroyuki Kurota ◽  
Murdoch K. McAllister ◽  
Eric A. Parkinson ◽  
N.T. Johnston
Keyword(s):  
Species Interactions ◽  
Single Species ◽  
Reference Points ◽  
Management Policy ◽  
Management Approach ◽  
Lake Ecosystem ◽  
Large Lake ◽  
Ecosystem Models ◽  
Predator Prey ◽  
Results Management

Ecosystem models are thought to offer advantages over single-species models in terms of management policy analysis. This hypothesis has proven difficult to test because of underlying system complexities, coupled with short time series and minimal contrast in environmental conditions or management policies. This paper presents a Bayesian statistical catch-at-age model to compare ecosystem models and test hypotheses about the management of a recreational fishery based on a predator–prey system using a relatively simple and data-rich ecosystem in a large lake, Kootenay Lake, British Columbia, where kokanee (Oncorhynchus nerka) are the prey and piscivorous rainbow trout (Oncorhynchus mykiss) are the predator. A model that explicitly incorporates the predator–prey interaction explained long-term data of field and fishery surveys much better than single-species models without any interactions. Minimally realistic multispecies models that treated predation identically but differed in their representation of the effects of prey abundance on predator mortality produced quite different results. Management reference points, for example, differed considerably between the models. Our study thus emphasizes that the choice of a management approach for this type of fishery will depend strongly on the model form and should take into consideration results from empirically based models that include species interactions.

scholarly journals Virtual Reality Camera Technology Facilitates Sampling of Interactions Between Reef Piscivores and Prey

2021 ◽  
Vol 55 (2) ◽  
pp. 54-63
Author(s):  
Peter J. Auster ◽  
Lissa Giacalone
Keyword(s):  
Virtual Reality ◽  
Species Interactions ◽  
Food Habit ◽  
Field Of View ◽  
Overlying Water ◽  
Predator Prey ◽  
Video Cameras ◽  
Direct Observations ◽  
Observer Effects ◽  
Subtropical Reefs

Abstract Predation is an important process influencing the structure of fish communities. There are multiple approaches used to quantify predatory interactions, and all approaches are beneficial but have their limitations. For example, food habit studies only represent results of successful predation events, direct observations by divers are time limited by both depth and temperature as well as observer effects, acoustic approaches cannot directly identify species, and video has field-of-view constraints when using standard cameras. While no approach is without constraints, the recent availability of small off-the-shelf virtual reality (VR) video cameras that can be used in marine environments offers a more spatially comprehensive field-of-view for conducting studies of community composition and species interactions both on the seafloor and in the overlying water column. Here, we demonstrate an approach for collection and analysis of data from stationary VR video to quantify predator-prey interactions at subtropical reefs in Gray’s Reef National Marine Sanctuary (NW Atlantic). This approach does not substitute for other widely used census and behavioral research approaches but augments those with unique analytical products and interpretation.

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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