Generalized estimating equations: A pragmatic and flexible approach to the marginal<scp>GLM</scp>modelling of correlated data in the behavioural sciences

Pekár, Stano; Brabec, Marek

doi:10.1111/eth.12713

Cited by 144 publications

(93 citation statements)

References 19 publications

(25 reference statements)

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“…Estimating Equations with Gamma error structure (GEE-g) (Pekár & Brabec, 2018). We used the geglme function from the geepack package (Yan & Fine, 2004) within the R environment (R Core Team, 2015).…”

Section: Statistical Analysesmentioning

confidence: 99%

Venom of prey‐specialized spiders is more toxic to their preferred prey: A result of prey‐specific toxins

Pekár

Líznarová

Bočánek

et al. 2018

Journal of Animal Ecology

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In specialized predators, a variety of adaptations have evolved to such a level of specificity that they allow very effective exploitation of focal prey. Venom is an essential adaptive trait of predatory venomous species, such as spiders, yet our knowledge of spider venom is incomplete. In agreement with the prey preference hypothesis, we expected that the venom of spider specialists should be more toxic to focal than to alternative prey, because it is composed of prey-specific toxins. Here we used spiders with three types of trophic specializations: specialists that were ant-eating, termite-eating and spider-eating. We compared the efficacy of prey capture of preferred and alternative prey (measured as paralysis latency) with that of related generalists and profiled the venom of the studied species using proteomic methods. We used 22 spider species: six myrmecophagous, two termitophagous, three araneophagous and 11 euryphagous generalist species belonging to different families. We found that ten of the eleven specialist species induced significantly shorter paralysis latency in preferred prey than in alternative prey. Generalists exhibited either similar efficiency on both prey types or slightly higher efficiency on preferred prey. Multivariate analysis of proteomic profiles (peptides and proteins) revealed significant differences between trophic specializations, particularly in peptides. Specialists appear to have venom composed of unique specific compounds as revealed by the multivariate ordination and indicator analysis. These components are likely prey-specific toxins.

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Section: Statistical Analysesmentioning

confidence: 99%

Venom of prey‐specialized spiders is more toxic to their preferred prey: A result of prey‐specific toxins

Pekár

Líznarová

Bočánek

et al. 2018

Journal of Animal Ecology

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“…The occurrence of different stages of Mexcala were related to the occurrence of six most abundant ant species by means of generalised estimating equations with Poisson distribution (GEE-p) from the geepack 36 within R 37 . GEE is an extension of GLM for correlated data 38 and was used in order to take into account joined occurrence of different stages of Mexcala on the same tree (i.e. nested observations).…”

Section: Methodsmentioning

confidence: 99%

No ontogenetic shift in the realised trophic niche but in Batesian mimicry in an ant-eating spider

Pekár

Dušátková

Haddad

2020

Sci Rep

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In predators an ontogenetic trophic shift includes change from small to large prey of several different taxa. in myrmecophagous predators that are also mimics of ants, the ontogenetic trophic shift should be accompanied by a parallel mimetic change. our aim was to test whether ant-eating jumping spider, Mexcala elegans, is myrmecomorphic throughout their ontogenetic development, and whether there is an ontogenetic shift in realised trophic niche and their mimetic models. We performed field observations on the association of Mexcala with ant species and investigated the natural prey of the ontogenetic classes by means of molecular methods. then we measured the mimetic similarity of ontogenetic morphs to putative mimetic models. We found Mexcala is an inaccurate mimic of ants both in the juvenile and adult stages. During ontogenesis it shifts mimetic models. the mimetic similarity was rather superficial, so an average bird predator should distinguish spiders from ants based on colouration. The realised trophic niche was narrow, composed mainly of ants of different species. There was no significant difference in the prey composition between ontogenetic stages. Females were more stenophagous than juveniles. We conclude that Mexcala is an ant-eating specialist that reduces its prey spectrum and shifts ant models during ontogenesis.

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“…For this, the function rarefaction from [38] based on the function rarefy from package vegan [39] was used. Then, the abundance among guilds of spiders (i.e., count data) was compared for each sampling date using generalized estimating equations (GEE) with Poisson distribution, an extension of generalized linear models (GLM) [40,41] followed by a posthoc Tukey test. In all cases, the correlation structure used was "exchangeable" (i.e., a single correlation parameter, ρ) and the grove was used for clustering.…”

Section: Field Sampling Schemementioning

confidence: 99%

A Guild-Based Protocol to Target Potential Natural Enemies of Philaenus spumarius (Hemiptera: Aphrophoridae), a Vector of Xylella fastidiosa (Xanthomonadaceae): A Case Study with Spiders in the Olive Grove

Benhadi‐Marín

Villa

Pereira

et al. 2020

Insects

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The olive grove is a key landscape across the Mediterranean basin. This agroecosystem is threatened by Xylella fastidiosa, the causal agent of the olive tree quick decline syndrome, Philaenus spumarius being the main vector. A way to limit pest populations relies on the use of biological control agents such as arthropods. Among them, spiders are generalist predators with different hunting strategies that feed mostly on insects and can contribute to limit pests. In this work, field and laboratory data were used to provide a protocol aiming to facilitate the selection of species of spiders among different guilds that could represent potential natural enemies of P. spumarius. Sampling of spiders was conducted in olive groves in northeastern Portugal. Two species, namely the orb-weaver Araniella cucurbitina and the ambusher Synema globosum, were selected according to the dominant guilds of spiders inhabiting the olive crop. We tested the differences of potential predatory efficiency using classical functional response tests with P. spumarius as prey. A type-II functional response was found for A. cucurbitina, whereas a type-I response was found for S. globosum. This difference uncovers a different potential efficiency among the two species as natural enemies of P. spumarius with relevant implications at high prey density in the field. A conceptual workflow to follow the fieldwork and selection of species for further work (i.e., laboratory assays) is provided and discussed. Standardized methods regarding the assessment of the suitability and efficiency of potential natural enemies are essential for the integration of results at different geographical extents and crops. Selecting functional counterparts such as different species of predators occurring at different locations that use the same prey (e.g., a pest) in the same way (e.g., hunting strategy) would facilitate developing biological control schemes.

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Generalized estimating equations: A pragmatic and flexible approach to the marginalGLMmodelling of correlated data in the behavioural sciences

Cited by 144 publications

References 19 publications

Venom of prey‐specialized spiders is more toxic to their preferred prey: A result of prey‐specific toxins

Venom of prey‐specialized spiders is more toxic to their preferred prey: A result of prey‐specific toxins

No ontogenetic shift in the realised trophic niche but in Batesian mimicry in an ant-eating spider

A Guild-Based Protocol to Target Potential Natural Enemies of Philaenus spumarius (Hemiptera: Aphrophoridae), a Vector of Xylella fastidiosa (Xanthomonadaceae): A Case Study with Spiders in the Olive Grove

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