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Ecological networks, usually depicting interactions among species, have been recently down‐scaled to the individual level, permitting description of patterns of inter‐individual resource variation that are usually hindered at the species level. Optimal diet theory (ODT) models, applied to prey–predator systems, predict different patterns of nestedness and modularity in the network, depending on the available resources and intra‐specific competition. The effect of resource availability on the emergence of networks structures, and ODT framework, has not yet fully been clarified. Here, we analyzed the structural patterns of individual‐resource networks in 3 species of Mediterranean salamanders, in relation to changes in prey availability. We used weighted individual‐resource network metrics to interpret the observed patterns, according to 3 ODT models. We found significant nestedness recurring in our study system, indicating that both selective and opportunistic individuals occur in the same population. Prey diversity, rather than abundance, was apparently related to inter‐individual resource variation and promoted the emergence of significant modularity within all networks. The observed patterns of nestedness and modularity, together with the variation in resource diversity and intra‐specific competition, are in agreement with the distinct preferences model of ODT. These findings suggest that in the focal prey–predator systems, individuals were able to perceive changes in prey diversity and to exploit in different ways the variations in composition of available resources, shifting their diet assembly rules accordingly. Our findings also confirm that the use of weighted individual‐resource networks, in prey–predator systems, allows to disclose dynamics that are masked at the species or population level. [ABSTRACT FROM AUTHOR]

Abstract Background It has been suggested that Plethodontid salamanders are excellent candidates for indicating ecosystem health. However, detailed, long-term data sets of their populations are rare, limiting our understanding of the demographic processes underlying their population fluctuations. Here we present a demographic analysis based on a 1996 - 2008 data set on an underground population of Speleomantes strinatii (Aellen) in NW Italy. We utilised a Bayesian state-space approach allowing us to parameterise a stage-structured Lefkovitch model. We used all the available population data from annual temporary removal experiments to provide us with the baseline data on the numbers of juveniles, subadults and adult males and females present at any given time. Results Sampling the posterior chains of the converged state-space model gives us the likelihood distributions of the state-specific demographic rates and the associated uncertainty of these estimates. Analysing the resulting parameterised Lefkovitch matrices shows that the population growth is very close to 1, and that at population equilibrium we expect half of the individuals present to be adults of reproductive age which is what we also observe in the data. Elasticity analysis shows that adult survival is the key determinant for population growth. Conclusion This analysis demonstrates how an understanding of population demography can be gained from structured population data even in a case where following marked individuals over their whole lifespan is not practical.

Unexpectedly, in the period 2015-2019, the covers of animal behaviour journals comprised the complete sequence of graphical layouts published by a medical journal over 70 years (Palileo & Kaunitz [9]). Our study suggested that several animal behaviour journals were relatively unconcerned towards the graphical layout, updating and attractiveness of the cover image that was accessible on the official journal website. However, in the period 2015-2019 the journal "Brain Behavior and Evolution" focused mainly on vertebrates, with more than 90% of articles dealing with this animal group, and thus preventing a more general assessment (Supplementary Material, Table S4). [Extracted from the article]

In amphibians, the study of trophic niche is important to better understand the species ecological adaptation, in particular along gradients or in heterogeneous habitats. In this framework, we analysed the trophic strategies of two populations of the endemic Corsican brook newt Euproctus montanus, one living in a Mediterranean lowland and the other in a mountain stream. In both sites, we performed dietary analysis using stomach flushing and assessed the available invertebrate prey community. Further, we estimated newt density using removal sampling. Streams were similar in invertebrate prey abundance (P = 0.15), but differed in prey diversity (P < 0.001), the Mediterranean lowland site possessing a higher diversity of invertebrate prey. The newts' trophic strategies were analysed at the population level and also at the individual one to assess in detail the trophic specialization. In both sites newt density was similar and the population realized trophic niche displayed a large overlap with the available prey community. Therefore, both populations behaved as broad trophic generalists. However, in the Mediterranean lowland stream, where available resources were more diverse, there was evidence of a significant degree of individual trophic specialization. This finding is consistent with the classic niche variation hypothesis, that predicts a higher individual differentiation in presence of high resource diversity. [ABSTRACT FROM AUTHOR]

The Stripeless tree-frog Hyla meridionalis reaches its eastern-most European distributional limit in NW Italy, and specifically in the Cinque Terre National Park. Here for two consecutive years, we estimated tree-frog population abundance by call surveys at 24 sites. Data were analysed in the framework of N-mixture open population models based on repeated counts of calling males. The results obtained by this statistical approach were effective in estimating population size together with annual recruitment and survival. The tree-frog male population size remained constant between years and site abundance was inversely related with altitude. On the bases of these findings, our application of N-mixture models to tree-frog calling males was successful and is a promising cost-effective method to obtain long-term monitoring data on this species over large geographic areas. [ABSTRACT FROM AUTHOR]