scholarly journals Variable coloration is associated with dampened population fluctuations in noctuid moths

2015 ◽  
Vol 282 (1808) ◽  
pp. 20142922 ◽  
Author(s):  
Anders Forsman ◽  
Per-Eric Betzholtz ◽  
Markus Franzén
Keyword(s):  
Individual Variation ◽  
Time Series Data ◽  
Biotic Interactions ◽  
Colour Pattern ◽  
Series Data ◽  
Population Fluctuations ◽  
Population Abundance ◽  
In The Wild ◽  
Colour Patterns ◽  
Abundance Fluctuations

Theory and recent reviews state that greater genetic and phenotypic variation should be beneficial for population abundance and stability. Experimental evaluations of this prediction are rare, of short duration and conducted under controlled environmental settings. The question whether greater diversity in functionally important traits stabilizes populations under more complex ecological conditions in the wild has not been systematically evaluated. Moths are mainly nocturnal, with a large variation in colour patterns among species, and constitute an important food source for many types of organisms. Here, we report the results of a long-term (2003–2013) monitoring study of 115 100 noctuid moths from 246 species. Analysis of time-series data provide rare evidence that species with higher levels of inter-individual variation in colour pattern have higher average abundances and undergo smaller between-year fluctuations compared with species having less variable colour patterns. The signature of interspecific temporal synchronization of abundance fluctuations was weak, suggesting that the dynamics were driven by species-specific biotic interactions rather than by some common, density-independent factor(s). We conclude that individual variation in colour patterns dampens population abundance fluctuations, and suggest that this may partly reflect that colour pattern polymorphism provides protection from visually oriented predators and parasitoids.

scholarly journals Uncertainty quantification of the effects of biotic interactions on community dynamics from nonlinear time-series data

2018 ◽  
Vol 15 (147) ◽  
pp. 20180695 ◽  
Author(s):  
Simone Cenci ◽  
Serguei Saavedra
Keyword(s):  
Time Series ◽  
Community Dynamics ◽  
Time Series Data ◽  
Multivariate Time Series ◽  
Model Averaging ◽  
Biotic Interactions ◽  
Series Data ◽  
Time Intervals ◽  
Novel Approach ◽  
Data Generating Process

Biotic interactions are expected to play a major role in shaping the dynamics of ecological systems. Yet, quantifying the effects of biotic interactions has been challenging due to a lack of appropriate methods to extract accurate measurements of interaction parameters from experimental data. One of the main limitations of existing methods is that the parameters inferred from noisy, sparsely sampled, nonlinear data are seldom uniquely identifiable. That is, many different parameters can be compatible with the same dataset and can generalize to independent data equally well. Hence, it is difficult to justify conclusive assertions about the effect of biotic interactions without information about their associated uncertainty. Here, we develop an ensemble method based on model averaging to quantify the uncertainty associated with the effect of biotic interactions on community dynamics from non-equilibrium ecological time-series data. Our method is able to detect the most informative time intervals for each biotic interaction within a multivariate time series and can be easily adapted to different regression schemes. Overall, this novel approach can be used to associate a time-dependent uncertainty with the effect of biotic interactions. Moreover, because we quantify uncertainty with minimal assumptions about the data-generating process, our approach can be applied to any data for which interactions among variables strongly affect the overall dynamics of the system.

scholarly journals Wildlife trade and consumer preference for species rarity: an examination of caged-bird markets in Sumatra

2019 ◽  
Vol 24 (04) ◽  
pp. 339-360 ◽  
Author(s):  
Vijesh V. Krishna ◽  
Kevin Darras ◽  
Ingo Grass ◽  
Yeni A. Mulyani ◽  
Dewi M. Prawiradilaga ◽  
...  
Keyword(s):  
Rare Species ◽  
Time Series Data ◽  
Consumer Preference ◽  
Wildlife Trade ◽  
Series Data ◽  
Demand And Supply ◽  
In The Wild ◽  
Preferred Species ◽  
Species Rarity ◽  
Analysis Of Time Series

AbstractThis study examines conservation effects of wildlife trade using demand and supply data from caged-bird markets in Sumatra, Indonesia. When consumers have a strong preference for species rarity, trade could result in wildlife overexploitation and species extinction. Results from a choice experiment show that buyers of caged birds indeed value species rarity. However, not all rare species are equally preferred. Species that are frequently traded lose their rarity value, even if rare in the wild. Analysis of time-series data collected from traders over a period of 20 months between 2013 and 2015 reveals an inelastic supply function for rare species, with market arrivals being insensitive to price changes. This may be due to a declining stock of rare species in the wild. Bird trade together with habitat loss can lead to extinction of a number of rare species in Indonesia. Several policy approaches on regulating caged-bird markets are discussed.

scholarly journals Risk of social colours in an agamid lizard: implications for the evolution of dynamic signals

2019 ◽  
Vol 15 (5) ◽  
pp. 20190207 ◽  
Author(s):  
Madhura S. Amdekar ◽  
Maria Thaker
Keyword(s):  
Natural Selection ◽  
Social Interactions ◽  
Predation Risk ◽  
Colour Pattern ◽  
Male Aggression ◽  
Visual Systems ◽  
In The Wild ◽  
Predation Costs ◽  
Colour Patterns ◽  
Ecological Cost

The forces of sexual and natural selection are typically invoked to explain variation in colour patterns of animals. Although the benefits of conspicuous colours for social signalling are well documented, evidence for their ecological cost, especially for dynamic colours, remains limited. We examined the riskiness of colour patterns of Psammophilus dorsalis , a species in which males express distinct colour combinations during social interactions. We first measured the conspicuousness of these colour patterns on different substrates based on the visual systems of conspecifics and predators (bird, snake, canid) and then quantified actual predation risk on these patterns using wax/polymer lizard models in the wild. The black and red male state exhibited during courtship was the most conspicuous to all visual systems, while the yellow and orange male aggression state and the brown female colour were least conspicuous. Models bearing the courtship colour pattern experienced the highest predator attacks, irrespective of the substrate they were placed on. Thus, social colours of males are not only conspicuous but also risky. Using physiological colours to shift in and out of conspicuous states may be an effective evolutionary solution to balance social signalling benefits with predation costs.

scholarly journals Individual variation in residency and regional movements of reef manta rays Mobula alfredi in a large marine protected area

2020 ◽  
Vol 639 ◽  
pp. 137-153 ◽  
Author(s):  
S Andrzejaczek ◽  
TK Chapple ◽  
DJ Curnick ◽  
AB Carlisle ◽  
M Castleton ◽  
...  
Keyword(s):  
Individual Variation ◽  
Protected Area ◽  
Spatial Ecology ◽  
Large Scale ◽  
Time Series Data ◽  
Marine Protected Area ◽  
Movement Patterns ◽  
Conservation Strategies ◽  
Series Data ◽  
Large Individual

Mobulid populations are declining on a global scale as a result of both targeted fisheries and indirect anthropogenic threats. In order to implement effective conservation strategies for species of this taxa, it is crucial that movement patterns at a range of spatiotemporal scales are defined. To gain insight into such patterns, we deployed a combination of acoustic (n = 21) and satellite (n = 12) tags on reef manta rays Mobula alfredi in the British Indian Ocean Territory Marine Protected Area (BIOT MPA) annually from 2013 through 2016. An extensive array of acoustic receivers (n = 52) were deployed across the archipelago to record the movements of mantas throughout the MPA. Data revealed large individual variation in horizontal movement patterns, ranging from high local site fidelity (<10 km) for up to 3 yr, to large-scale regional movements (>200 km) around the entire MPA. Depth time-series data recorded vertical movement patterns consistent with other epipelagic elasmobranch species, including oscillatory diving and deep dives to greater than 500 m. Though no individuals were directly recorded departing the MPA throughout the study, the gaps in detections and estimated travel speeds documented here indicate that movement of individuals outside of the BIOT MPA cannot be discounted. Collectively, our data suggests that, with effective enforcement, the current size of the BIOT MPA is providing substantial protection to its reef manta ray population. Characterization of movement patterns across ontogenetic classes, however, is required to fully characterize the spatial ecology of this species and ensure protection across all cohorts of the population.

scholarly journals Uncovering the effects of Müllerian mimicry on the evolution of conspicuousness in colour patterns

2019 ◽  
Author(s):  
Ombeline Sculfort ◽  
Ludovic Maisonneuve ◽  
Marianne Elias ◽  
Thomas G. Aubier ◽  
Violaine Llaurens
Keyword(s):  
Predation Risk ◽  
Prey Species ◽  
Colour Pattern ◽  
Warning Coloration ◽  
Local Composition ◽  
Müllerian Mimicry ◽  
In The Wild ◽  
Mullerian Mimicry ◽  
Colour Patterns ◽  
Number Of Individuals

AbstractThe conspicuousness of colour pattern in defended species associates with a high detectability by predators, making its evolution puzzling. Müllerian mimicry, the convergence of warning coloration among defended prey species, is pervasive in communities of conspicuous prey, and mimicry switches, with mutant individuals having the same colour pattern as other co-mimetic species, may often associate with changes in conspicuousness. Yet, the implication of mimicry for the evolution of conspicuousness has not been considered. Here, we build a model describing the population dynamics of conspicuous defended prey to explore the invasion conditions of mutants that differ from other individuals by their conspicuousness. We assume that predation risk depends not only on the number of individuals sharing a given colour pattern within the population but also on the presence of co-mimetic species. We compare the evolutionary fates of mutant colour patterns (1) that are similar to the ancestral colour pattern and thus belong to the same mimicry ring (assemblage of co-mimetic species), or (2) that are different from the ancestral colour pattern and thus potentially belong to a distinct mimicry ring. Our analytical derivations show that (1) less conspicuous colour patterns are more likely to be selected within mimicry ring, and that (2) a mimicry switch lowering predation risk can promote the invasion of a more conspicuous colour pattern. We thus highlight that the variation in conspicuousness observed in the wild results not only from the characteristics of the colour pattern (detectability, salience) but also from the local composition of mimetic communities.

scholarly journals HIGH-RESOLUTION CHARACTERIZATION OF MALE ORNAMENTATION AND REEVALUATION OF SEX LINKAGE IN GUPPIES

2020 ◽  
Author(s):  
Jake Morris ◽  
Iulia Darolti ◽  
Wouter van der Bijl ◽  
Judith E. Mank
Keyword(s):  
High Resolution ◽  
Natural Populations ◽  
Colour Pattern ◽  
Sexually Dimorphic ◽  
Animal Colouration ◽  
In The Wild ◽  
Colour Changes ◽  
Colour Patterns ◽  
Male Ornaments

AbstractColouration plays a key role in the ecology of many species, influencing how an organism interacts with its environment, other species and conspecifics. Guppies are sexually dimorphic, with males displaying sexually selected colouration resulting from female preference. Previous work has suggested that much of guppy colour pattern variation is Y-linked. However, it remains unclear how many individual colour patterns are Y-linked in natural populations as much of the previous work has focused on phenotypes either not found in the wild, or aggregate measures such as total colour area. Moreover, ornaments have traditionally been identified and delineated by hand, and computational methods now make it possible to extract pixels and identify ornaments more automatedly, reducing the potential for human bias. Here we developed a pipeline for automated ornament identification and high-resolution image analysis of male guppy colour patterns and applied it to a multigenerational pedigree. Our results show that loci controlling the presence or absence of individual male ornaments in our population are not predominantly Y-linked. However, we find that ornaments of similar colour are not independent of each other, and modifier loci that affect whole animal colouration appear to be at least partially Y-linked. Considering these results, Y-linkage of individual ornaments may not be important in driving colour changes in natural populations of guppies, or in expansions of the non-recombining Y region, while Y-linked modifier loci that affect aggregate traits may well play an important role.

scholarly journals High-resolution characterization of male ornamentation and re-evaluation of sex linkage in guppies

2020 ◽  
Vol 287 (1937) ◽  
pp. 20201677
Author(s):  
Jake Morris ◽  
Iulia Darolti ◽  
Wouter van der Bijl ◽  
Judith E. Mank
Keyword(s):  
High Resolution ◽  
Natural Populations ◽  
Colour Pattern ◽  
Sexually Dimorphic ◽  
In The Wild ◽  
Colour Changes ◽  
Colour Patterns ◽  
Male Ornaments ◽  
Automated Methods

Coloration plays a key role in the ecology of many species, influencing how an organism interacts with its environment, other species and conspecifics. Guppies are sexually dimorphic, with males displaying sexually selected coloration resulting from female preference. Previous work has suggested that much of guppy colour pattern variation is Y-linked. However, it remains unclear how many individual colour patterns are Y-linked in natural populations as much of the previous work has focused on phenotypes either not found in the wild, or aggregate measures such as total colour area. Moreover, ornaments have traditionally been identified and delineated by hand, and computational methods now make it possible to extract pixels and identify ornaments with automated methods, reducing the potential for human bias. Here we developed a pipeline for semi-automated ornament identification and high-resolution image analysis of male guppy colour patterns and applied it to a multigenerational pedigree. Our results show that loci controlling the presence or the absence of individual male ornaments in our population are not predominantly Y-linked. However, we find that ornaments of similar colour are not independent of each other, and modifier loci that affect whole animal coloration appear to be at least partially Y-linked. Considering these results, Y-linkage of individual ornaments may not be important in driving colour changes in natural populations of guppies, or in expansions of the non-recombining Y region, while Y-linked modifier loci that affect aggregate traits may well play an important role.

Graphical Exploratory Data Analysis for Categorical Longitudinal and Time Series Data

2013 ◽  
Author(s):  
Stephen J. Tueller ◽  
Richard A. Van Dorn ◽  
Georgiy Bobashev ◽  
Barry Eggleston
Keyword(s):  
Time Series ◽  
Data Analysis ◽  
Exploratory Data Analysis ◽  
Time Series Data ◽  
Series Data ◽  
Exploratory Data

Some statistical and CI models to predict chaotic high-frequency financial data

2020 ◽  
Vol 39 (5) ◽  
pp. 6419-6430
Author(s):  
Dusan Marcek
Keyword(s):  
Time Series Data ◽  
Moving Average ◽  
Methodological Approach ◽  
Back Propagation ◽  
Large Data ◽  
Series Data ◽  
Data Set ◽  
Training Time ◽  
Optimal Population ◽  
Forecast Time

To forecast time series data, two methodological frameworks of statistical and computational intelligence modelling are considered. The statistical methodological approach is based on the theory of invertible ARIMA (Auto-Regressive Integrated Moving Average) models with Maximum Likelihood (ML) estimating method. As a competitive tool to statistical forecasting models, we use the popular classic neural network (NN) of perceptron type. To train NN, the Back-Propagation (BP) algorithm and heuristics like genetic and micro-genetic algorithm (GA and MGA) are implemented on the large data set. A comparative analysis of selected learning methods is performed and evaluated. From performed experiments we find that the optimal population size will likely be 20 with the lowest training time from all NN trained by the evolutionary algorithms, while the prediction accuracy level is lesser, but still acceptable by managers.

Faktor-Faktor Yang Mempengaruhi Nilai Tukar Dollar Amerika Serikat Terhadap Rupiah Tahun 2000–2013

2017 ◽  
Vol 1 (2) ◽  
pp. 177-191
Author(s):  
Rizki Rahma Kusumadewi ◽  
Wahyu Widayat
Keyword(s):  
Time Series ◽  
Exchange Rate ◽  
Money Supply ◽  
Time Series Data ◽  
The United States ◽  
Economic Conditions ◽  
Series Data ◽  
Arch Model ◽  
United States Dollar ◽  
The Exchange Rate

Exchange rate is one tool to measure a country’s economic conditions. The growth of a stable currency value indicates that the country has a relatively good economic conditions or stable. This study has the purpose to analyze the factors that affect the exchange rate of the Indonesian Rupiah against the United States Dollar in the period of 2000-2013. The data used in this study is a secondary data which are time series data, made up of exports, imports, inflation, the BI rate, Gross Domestic Product (GDP), and the money supply (M1) in the quarter base, from first quarter on 2000 to fourth quarter on 2013. Regression model time series data used the ARCH-GARCH with ARCH model selection indicates that the variables that significantly influence the exchange rate are exports, inflation, the central bank rate and the money supply (M1). Whereas import and GDP did not give any influence.

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