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Biodiversity is being lost at an unprecedented rate, and monitoring is crucial for understanding the causal drivers and assessing solutions. Most biodiversity monitoring data are collected by volunteers through citizen science projects, and often crucial information is lacking to account for the inevitable biases that observers introduce during data collection. We contend that citizen science projects intended to support biodiversity monitoring must gather information about the observation process as well as species occurrence. We illustrate this using eBird, a global citizen science project that collects information on bird occurrences as well as vital contextual information on the observation process while maintaining broad participation. Our fundamental argument is that regardless of what species are being monitored, when citizen science projects collect a small set of basic information about how participants make their observations, the scientific value of the data collected will be dramatically improved. [ABSTRACT FROM AUTHOR]

With the internet, a massive amount of information on species abundance can be collected by citizen science programs. However, these data are often difficult to use directly in statistical inference, as their collection is generally opportunistic, and the distribution of the sampling effort is often not known. In this article, we develop a general statistical framework to combine such 'opportunistic data' with data collected using schemes characterized by a known sampling effort. Under some structural assumptions regarding the sampling effort and detectability, our approach makes it possible to estimate the relative abundance of several species in different sites. It can be implemented through a simple generalized linear model. We illustrate the framework with typical bird datasets from the Aquitaine region in south-western France. We show that, under some assumptions, our approach provides estimates that are more precise than the ones obtained from the dataset with a known sampling effort alone. When the opportunistic data are abundant, the gain in precision may be considerable, especially for rare species. We also show that estimates can be obtained even for species recorded only in the opportunistic scheme. Opportunistic data combined with a relatively small amount of data collected with a known effort may thus provide access to accurate and precise estimates of quantitative changes in relative abundance over space and/or time. [ABSTRACT FROM AUTHOR]

The rapid expansion of systematic monitoring schemes necessitates robust methods to reliably assess species' status and trends. Insect monitoring poses a challenge where there are strong seasonal patterns, requiring repeated counts to reliably assess abundance. Butterfly monitoring schemes ( BMSs) operate in an increasing number of countries with broadly the same methodology, yet they differ in their observation frequency and in the methods used to compute annual abundance indices., Using simulated and observed data, we performed an extensive comparison of two approaches used to derive abundance indices from count data collected via BMS, under a range of sampling frequencies. Linear interpolation is most commonly used to estimate abundance indices from seasonal count series. A second method, hereafter the regional generalized additive model ( GAM), fits a GAM to repeated counts within sites across a climatic region. For the two methods, we estimated bias in abundance indices and the statistical power for detecting trends, given different proportions of missing counts. We also compared the accuracy of trend estimates using systematically degraded observed counts of the Gatekeeper Pyronia tithonus (Linnaeus 1767)., The regional GAM method generally outperforms the linear interpolation method. When the proportion of missing counts increased beyond 50%, indices derived via the linear interpolation method showed substantially higher estimation error as well as clear biases, in comparison to the regional GAM method. The regional GAM method also showed higher power to detect trends when the proportion of missing counts was substantial., Synthesis and applications. Monitoring offers invaluable data to support conservation policy and management, but requires robust analysis approaches and guidance for new and expanding schemes. Based on our findings, we recommend the regional generalized additive model approach when conducting integrative analyses across schemes, or when analysing scheme data with reduced sampling efforts. This method enables existing schemes to be expanded or new schemes to be developed with reduced within-year sampling frequency, as well as affording options to adapt protocols to more efficiently assess species status and trends across large geographical scales. [ABSTRACT FROM AUTHOR]

Abstract: Control to limit damage caused by undesirable organisms at the country level is a common management practice but its effects on the target populations are usually unknown. Monitoring consequences of control is however important to design and measure the efficacy of long-term management. Using data from the French Breeding Bird Survey and methodology that cope with detection bias, we studied the consequences of trapping on the age structure and spatial dynamics of the magpie (Pica pica), a bird considered as a pest species in France. Our results show that magpie occurrence in farmlands and semi-natural landscapes decreases with regional trapping intensity. Trapping increase the probability of populations becoming extinct locally, with less possibility of (re)colonising managed areas. Local extinction is likely the consequences of changes in the age structure of breeding populations which are composed of more immatures in intensively trapped areas. The effects of trapping are however mitigated in urban areas, which have become a refuge habitat for magpies. Trapping is a long established and very common practice in France. Although trapping has a successful impact on the magpie in countryside, it is recommended only if justified by conservation specific purposes. Non-lethal methods exist like reducing availability of human-related food resources, especially in urban environments. Monitoring the dynamics behind species occurrence is a useful approach to understand how control affects species distribution. This study illustrates the value of a national monitoring scheme in helping to understand trapping consequences. [Copyright &y& Elsevier]

1. Ecological specialization is one of the main concepts in ecology and conservation. However, this concept has become highly context-dependent and is now obscured by the great variability of existing definitions and methods used to characterize ecological specialization. 2. In this study, we clarify this concept by reviewing the strengths and limitations of different approaches commonly used to define and measure ecological specialization. We first show that ecological specialization can either be considered as reflecting species’ requirements or species’ impacts. We then explain how specialization depends on species-specific characteristics and on local and contingent environmental constraints. We further show why and how ecological specialization should be scaled across spatial and temporal scales, and from individuals to communities. 3. We then illustrate how this review can be used as a practical toolbox to classify widely used metrics of ecological specialization in applied ecology, depending on the question being addressed, the method used, and the data available. 4. Synthesis and applications. Clarifying ecological specialization is useful to make explicit connections between several fields of ecology using the niche concept. Defining this concept and its practical metrics is also a crucial step to better formulate predictions of scientific interest in ecology and conservation. Finally, understanding the different facets of ecological specialization should facilitate to investigate the causes and consequences of biotic homogenization and to derive relevant indicators of biodiversity responses to land-use changes. [ABSTRACT FROM AUTHOR]

Responses of species to landscape modifications are generally documented through their distribution at a given time along an intensity gradient of land transformation. By focusing on patterns, we are limited to infer ecological processes occurring within a system and its response to environmental disturbances which can further change over time. Using diachronic datasets at the scale of France, we analyzed the spatial responses of the black-billed magpie, which has recently colonized cities, to landscape urbanization. This study applied recently developed statistical approaches incorporating detection uncertainty of the magpie, based on the capture-recapture statistical framework. We tested whether, and how, extinction and colonization mechanisms influenced variations of magpie occupancy from 2001 to 2005. In addition, we assessed the importance of the recent urbanization of the French countryside in determining population dynamics. Overall, our analysis proved that the proportion of urban areas and recent urbanization in France led to an increase in the probability of magpie occupancy. Unexpectedly, the species is concomitantly disappearing from the countryside, leading to a rapid change in the distribution of the species. This study stressed the importance of incorporating detection uncertainty in inference process about spatial dynamics. Overall, we show how useful it is to account for the dynamic evolution of the landscape in ecological studies. [ABSTRACT FROM AUTHOR]

Abstract: Some structures developed for particular technical anthropogenic uses are colonized by biodiversity, but their potential roles have not been seriously considered. Here, we examined whether and how highway stormwater retention ponds are colonized by amphibians and are used as reproduction sites in human-dominated landscapes. We addressed their role as habitats for amphibians by sampling amphibians in highway ponds (n =58) and in surrounding non-highway ponds (n =45) and comparing the species richness and the amphibian abundance using occupancy models that take detectability into account. As expected, highway ponds differed in abiotic conditions from surrounding ponds. Surprisingly, we found seven different amphibian species with breeding populations, including one emblematic rare species (Triturus cristatus), in these artificial ponds. Further, the proportion of the highway ponds where amphibians were detected was about similar to that of surrounding ponds. Note, however, that the amphibian abundances were lower in highway ponds. Surprisingly, our results suggest that highway ponds may contribute in altered landscapes to the biodiversity of the pond network at a regional scale. Because the adoption of biodiversity-friendly management measures for these artificial ponds could promote biodiversity in such landscapes, we highlight the most important factors driving amphibian distribution in these ponds. Due to the importance of these issues, we stress the need for complementary studies to continue to precisely examine the potential roles of these ponds as habitats for amphibians and then to propose, if useful, technical pond design and management recommendations relevant for common biodiversity. [Copyright &y& Elsevier]

Abstract: Urbanisation is affecting ecological communities worldwide. Despite the disproportionate impact on farmland over other habitats, the effect on farmland bird communities has been poorly studied. Considering the still-alarming conservation status of farmland birds, investigations into the effects of pressures such as urbanisation on those communities could be of great interest for their conservation. We studied the urbanisation effects on functional diversity using existing indices designed for the purpose of standardisation. This study uses a functional character measuring species habitat specialisation for indices calculation. A bird survey was conducted on 92 plots of 1 × 1 km chosen after stratification on the proportion of urban area and farmland habitat (either 0, 25, 50, 75%), with the focus on farmland habitat. Two aspects of urbanisation were studied: the intensity and the age of the urbanisation. Functional richness was found to decrease with urbanisation, while functional evenness and divergence increased in a nonlinear way. No significant difference was observed in functional richness and evenness with urbanisation age, however extreme ages of urbanisation (young and old) showed higher niche differentiation concerning specialisation. This implies less important resource competition for species and a more vulnerable state for the ecosystem. Using functional diversity indices based on specialisation allows a better insight in the consequences of urbanisation on diversity/ecosystem–community functioning, which is of crucial importance in the face of global changes. [Copyright &y& Elsevier]

Highlights: [•] We compared three landscape descriptions to model 47-bird species distribution. [•] The description including all land covers performed better for most species. [•] This description better detected sensitivity to landscape characteristics. [•] This description appeared to be accurate for multi-specific and community studies. [Copyright &y& Elsevier]