The Atlantic Forest is one of the most threatened biomes globally. Data from monitoring programs are necessary to evaluate the conservation status of species, prioritise conservation actions and to evaluate the effectiveness of these actions. Birds are particularly well represented in citizen-collected datasets that are used worldwide in ecological and conservation studies. Here, we analyse presence-only data from three online citizen science datasets of Atlantic Forest endemic bird species to evaluate whether the representation of these species was correlated with their global threat status, range and estimated abundance. We conclude that even though species are over- and under-represented with regard to their presumed abundance, data collected by citizen scientists can be used to infer species distribution and, to a lesser degree, species abundance. This pattern holds true for species across global threat status.

The Secretarybird Sagittarius serpentarius is a charismatic raptor of the grasslands and open savannas of Africa. Evidence of widespread declines across the continent has led to the assessment that the species is at risk of becoming extinct. Southern Africa was identified as a remaining stronghold for the species, but the status of this population requires reassessment. To determine the status of the species in South Africa, Lesotho, and Eswatini, we analysed data from a citizen science project, the Southern African Bird Atlas Project (SABAP). We implemented novel time-to-detection modelling, as well as summarisation of changes in reporting rates, using standard metrics, to determine the trajectory of the population. To cross-validate our findings, we used data from another citizen science project, the Coordinated Avifaunal Roadcounts (CAR) project. While our results were in agreement with previous studies that have reported significant declines when comparing SABAP1 (1987–1992) and SABAP2 (2007 and onwards), all analysis pathways that examined data within the SABAP2 period only, as well as CAR data from this period, failed to show an alarming declining trend over this more recent time period. We did, however, find some evidence for decreases in Secretarybird abundance in urban grid cells. We used random forest models to predict probability of occurrence, as well as probability of abundance (reporting rates) for the assessed region and provided population estimates based on these analysis pathways. Continued monitoring and conservation efforts are required to guard this population stronghold.

In Singapore, the Critically Endangered Sunda pangolin Manis javanica is threatened by habitat loss and fragmentation, and road traffic collisions. To mitigate these threats, an understanding of its spatiotemporal distribution is needed, as identified in the National Conservation Strategy and Action Plan for the species. However, Sunda pangolin occurrence data are held in multiple separate databases, are typically collected using non-standardized methods, and often lack accurate location details. To compile a complete georeferenced database of Sunda pangolin records in Singapore, we consolidated occurrence data from heterogeneous databases and mainstream and social media, and converted locality descriptions into geographical coordinates. We demonstrate the use of this database to analyse data on rescued pangolins and those killed on roads, to aid conservation efforts in Singapore, and describe other potential applications. We georeferenced 482 records of pangolin sightings, rescues and roadkill for 1996–2021, finding an increase in all three over the study period. Roadkill and rescues occurred mostly in central and western Singapore, close to forested areas, and were predominantly of subadults and adult males. The data can be used to inform threat mitigation strategies, post-rescue release plans and further research. The database has already been used in practice, contributing to environmental impact assessments and conservation recommendations. Overall, this georeferenced database demonstrates the value of citizen science and collating wildlife data from multiple sources, and the methods used can be applied to other taxa to aid conservation strategies.

The moderation of user-generated content on online platforms remains a key solution to protecting people online, but also remains a perpetual challenge as the appropriateness of content moderation guidelines depends on the online community that they aim to govern. This challenge affects marginalized groups in particular, as they more frequently experience online abuse but also end up falsely being the target of content-moderation guidelines. While there have been calls for democratic, community-moderation, there has so far been little research into how to implement such approaches. Here, we present the co-creation of content moderation strategies with the users of an online platform to address some of these challenges. Within the context of AutSPACEs—an online citizen science platform that aims to allow autistic people to share their own sensory processing experiences publicly—we used a community-based and participatory approach to co-design a content moderation solution that would fit the preferences, priorities, and needs of its autistic user community. We outline how this approach helped us discover context-specific moderation dilemmas around participant safety and well-being and how we addressed those. These trade-offs have resulted in a moderation design that differs from more general social networks in aspects such as how to contribute, when to moderate, and what to moderate. While these dilemmas, processes, and solutions are specific to the context of AutSPACEs, we highlight how the co-design approach itself could be applied and useful for other communities to uncover challenges and help other online spaces to embed safety and empowerment.

Environmental and anthropogenic factors may significantly affect the diffusion of wild animals, enhancing the interface of human–wildlife interactions and driving the spread of pathogens and vector-borne diseases between animals and humans. However, in the last decade, the involvement of citizens in scientific research (the so-called citizen science approach, henceforth abbreviated as CS) provided a network of large-scale and cost-effective surveillance programmes of wildlife populations and their related arthropod species. Therefore, this review aims to illustrate different methods and tools used in CS studies, by arguing the main advantages and considering the limitations of this approach. The CS approach has proven to be an effective method for establishing density and distribution of several wild animal species, in urban, peri-urban and rural environments, as well a source of information regarding vector–host associations between arthropods and wildlife. Extensive efforts are recommended to motivate citizens to be involved in scientific projects to improve both their and our knowledge of the ecology and diseases of wildlife. Following the One Health paradigm, collaborative and multidisciplinary models for the surveillance of wildlife and related arthropod species should be further developed by harnessing the potentiality of the CS approach.

Photographs of a single shark specimen (1040 mm in total length) caught in the Oyodo River estuary, Miyazaki Prefecture, Kyushu, Japan, by a recreational angler and uploaded to the social networking service Facebook, were identified as a juvenile specimen of the bull shark Carcharhinus leucas. The photographic record, now deposited in the Kanagawa Prefectural Museum of Natural History collection, represents the northernmost record of this species in the western Pacific Ocean. Although C. leucas is known to utilize primarily tropical estuarine habitats as nursery grounds, a few reports exist regarding the utilization of subtropical and warm-temperate latitude estuaries, as in this case. From the perspectives of species conservation and shark-bite mitigation in warm-temperate latitudes, further information on C. leucas occurrence around its northern distribution limit is required.

iNaturalist is a widely-utilized platform for data collection and sharing among non-professional volunteers and is widely employed in citizen science. This platform's data are also used in scientific studies for a wide range of purposes, including tracking changes in species distribution, monitoring the spread of alien-invasive species, and assessing the impacts of urbanization and land-use change on biodiversity. Lichens, due to their year-round presence on trees, soil and rocks, and their diverse shapes and colours, have captured the attention of iNaturalist users, and lichen records are widely represented on the platform. However, due to the complexity of lichen identification, the use of data collected by untrained, or poorly trained volunteers in scientific investigation poses concerns among lichenologists. To address these concerns, this study assessed the reliability of lichen identification by iNaturalist users by comparing records on the platform with identifications carried out by experts (experienced lichenologists) in three cities where citizen science projects were developed. Results of this study caution against the use of unchecked data obtained from the platform in lichenology, demonstrating substantial inconsistency between results gathered by iNaturalist users and experts.

Changes in abundance and distribution of marine top predators can indicate environmental change or anthropogenic pressure requiring management response. Here, we used an extensive dataset (21 years) to conduct a spatial and temporal analysis of grey seal strandings in Cornwall and the Isles of Scilly, close to the southern edge of the breeding range of the species. A total of 2007 strandings were reported from 2000 to 2020, increasing by 474% from 35 to 201 individuals per year during this period. The continued rise in strandings was consistent across all life stages and timeframes (5, 10 and 20 years), underpinning the suggestion of increasing abundance in the region. The observed seasonality differed by life stage, coinciding with the increased presence of animals near the coast for key life phases such as breeding, moulting and pupping. Strandings are widely distributed across the coast of Cornwall and the Isles of Scilly; however, most strandings were recorded on the north coast of Cornwall (70%) where major pupping and haul out sites are found. Despite hosting several pupping and haul out sites, a small proportion was recorded on the Isles of Scilly (5%) where it is thought that strandings are particularly underreported. Describing baselines in magnitude of strandings and life-stage compositions across space and time allows future deviations in frequency, demographic composition or spatial distribution to be detected and investigated. We demonstrate the utility of long-term citizen science data to provide valuable and cost-effective information on the distribution and abundance of a highly mobile marine mammal.

Microplastics are ubiquitous in our environment but their presence in air is less well understood. Homes are likely a key source of airborne microplastics and microfibres to the environment owing to the frequent use and storage of plastics and textiles within them. Studying their presence, concentration and distribution in these environments is difficult without the participation of citizens due to accessibility challenges. Few studies have examined the intricacies of the prevalence of indoor microplastics and microfibres or the link between indoor exposure and behavioural and regulatory approaches that could reduce their concentrations. The application of a quintuple innovation helix framework, within which a co-creative citizen science research methodology is applied, provides an opportunity for citizens to shape the scientific method, ensuring that methods are accessible and appropriate for widespread use and designed by the citizen, for the citizen. Exploring behaviours and motivations in plastic and textile use by citizens with industry may reduce the generation of these particles. Future studies should consider the importance of citizen inclusion when designing research strategies for measuring and reducing microplastic concentrations in homes, enabling a nuanced understanding of their generation and distribution and facilitating the development of appropriate behavioural, industrial and regulatory messaging and mitigative measures.

This research focus on the evaluation of the impact on students’ attitudes towards the environment, fostered by their involvement in an educational citizen science project related to the monitoring of physicochemical properties and the detection of (micro)plastics in Portuguese coastal waters. We developed an attitude scale, comprising four dimensions (Collective, Personal, Recycling and Reuse and Microplastics), which was applied, as a pre-test and post-test, to 574 middle school students (aged 12–14): 442 in the experimental group and 132 in the control group. Initially, based on pre-test results, both groups revealed positive attitudes. In the experimental group, the post-test results revealed that significantly positive attitude changes were promoted in all dimensions, whereas, in the control group, this occurred only in the Personal dimension. The control group also exhibited significantly negative attitude changes in the collective dimension. Students’ engagement in sustainability-related citizen science projects can enhance environmentally literate society.

Across South Africa, Lesotho, and Eswatini, long-term citizen science atlas data have suggested concerning declines in the population of Black Stork Ciconia nigra. Unlike the Asian and European populations, the southern African Black Stork population is described as resident and is listed as “Vulnerable” in South Africa, Lesotho, and Eswatini. Here we report on surveys of historical nesting locations across northern South Africa, finding evidence for nest site abandonment and limited evidence of recent breeding. We undertook detailed species distribution modelling within a maximum entropy framework, using occurrence records from the BirdLasser mobile app. We cross-validated the models against information in the Southern African Bird Atlas Project (SABAP2) database, highlighting Lesotho as an important potential breeding area. Additionally, we used SABAP2 to assess population trends by investigating interannual patterns in reporting rate. Comparing current reporting rates with those from SABAP1 (1987–1992), we found that there has been a dramatic decrease. We noted that a large proportion of the population occurs outside the breeding range during the breeding season, suggesting a considerable non-breeding population, especially in the extensive wildlife refuge of the Kruger National Park. The slow declines observed might be indicative of a population which is not losing many adults but is failing to recruit significant numbers of juveniles due to limited breeding. Using densities derived from transect surveys, we used predictive models to derive estimates of breeding range carrying capacity and a population estimate, which suggested declines to numbers around 600 for this subregion. Minimising disturbance at breeding sites of this cliff-nesting species and improving water quality at key population strongholds are pathways to improving the status of the species in the subregion.

Rome is a complex metropolis. The city faces the challenge of imagining and shaping an inclusive and sustainable future for its inhabitants. On several occasions, city policies and interventions have not met the goal of preserving environmental resources. For their part, the inhabitants of Rome tend to doubt the ability of institutions to take care of the city’s resources. We focus on civic environmental monitoring led by the local independent association A Sud, aimed at assessing the environmental status of two of the city’s rivers. From a review of applicable literature on governance, environmental and social justice and climate urbanism, we build a theoretical frame to guide our analysis. We inquire how civic monitoring in a complex city can benefit urban resource governance and foster urban transitions. We also explore the extent to which these initiatives have the potential to inform or have actually informed the scientists and policymakers responsible for designing city adaptations. Our analysis demonstrates that citizen-gathered data can enrich the scientific knowledge base and trigger claims for interventions, bringing in information on local issues often overlooked by competent institutions. The initiatives also improved individual and collective attitudes towards the city and its resources, stimulating a sense of care and a watchful citizenship.

Quantitative plant biology is a growing field, thanks to the substantial progress of models and artificial intelligence dealing with big data. However, collecting large enough datasets is not always straightforward. The citizen science approach can multiply the workforce, hence helping the researchers with data collection and analysis, while also facilitating the spread of scientific knowledge and methods to volunteers. The reciprocal benefits go far beyond the project community: By empowering volunteers and increasing the robustness of scientific results, the scientific method spreads to the socio-ecological scale. This review aims to demonstrate that citizen science has a huge potential (i) for science with the development of different tools to collect and analyse much larger datasets, (ii) for volunteers by increasing their involvement in the project governance and (iii) for the socio-ecological system by increasing the share of the knowledge, thanks to a cascade effect and the help of ‘facilitators’.