Citizen science is research conducted with the participation of the general public, amateur or nonprofessional researchers, or participants from the fields of science, social science, and many other disciplines. The exact definition of "citizen science" varies, with different individuals and organizations having their own specific interpretations of its scope. Citizen science is employed in a wide range of areas of study, including ecology, biology, conservation, health and medical research, astronomy, media and communications, and information science. The applications and functions of citizen science in research projects are multifaceted. Citizen science can be used as a methodology in which public volunteers help in data collection and classification, thereby improving the scientific community's capacity. Citizen science observations can be used to uncover general trends in native habitats across broad spatial and temporal scales, extending data collection beyond the capacity of individual researchers. These observations can then be integrated with findings from designed experiments to provide a more complete understanding of natural variation and ecological processes. Citizen science can also involve more direct involvement from the public, with communities initiating projects researching environment and health hazards within their own communities. Participation in citizen science projects also educates the public about the scientific process and increases awareness about different topics. Some schools incorporate citizen science projects as part of their teaching curricula for this very purpose. More recently, libraries have also emerged as community hubs for citizen science.
Background The first use of the term "citizen science" appeared in a January 1989 issue of the MIT Technology Review, which featured three community-based labs studying environmental issues. In the 21st century, the number of citizen science projects, publications, and funding opportunities has increased. Citizen science has been used more over time, a trend helped by technological advancements. Digital citizen science platforms, such as Zooniverse and iNaturalist, store large amounts of data for many projects and are a place where volunteers can learn how to contribute to projects. For some projects, participants are instructed to collect and enter data, such as the species they observed, into large digital global databases. For other projects, participants help classify data on digital platforms. Citizen science data is also being used to develop machine learning algorithms. An example is using volunteer-classified images to train machine learning algorithms to identify species. While global participation and global databases are found on online platforms, the uniformity of data from contributors across different locations is not guaranteed. Concerns over potential data quality issues in citizen science projects, including measurement errors and biases, are recognized in the scientific community. However, statistical solutions and best practices are available to assist in addressing these concerns.
Definition The term "citizen science" has multiple origins, as well as differing concepts. "Citizen" is used in the general sense, as meaning in "citizen of the world", or the general public, rather than the legal term citizen of sovereign countries. It was first defined independently in the mid-1990s by Rick Bonney in the United States and Alan Irwin in the United Kingdom. Alan Irwin, a British sociologist, defines citizen science as "developing concepts of scientific citizenship which foregrounds the necessity of opening up science and science policy processes to the public". Irwin sought to reclaim two dimensions of the relationship between citizens and science: 1) that science should be responsive to citizens' concerns and needs; and 2) that citizens themselves could produce reliable scientific knowledge. The American ornithologist Rick Bonney, unaware of Irwin's work, defined citizen science as projects in which nonscientists, such as amateur birdwatchers, voluntarily contributed scientific data. This describes a more limited role for citizens in scientific research than Irwin's conception of the term.
The terms citizen science and citizen scientists entered the Oxford English Dictionary (OED) in June 2014. "Citizen science" is defined as "scientific work undertaken by members of the general public, often in collaboration with or under the direction of professional scientists and scientific institutions". "Citizen scientist" is defined as: (a) "a scientist whose work is characterized by a sense of responsibility to serve the best interests of the wider community (now rare)"; or (b) "a member of the general public who engages in scientific work, often in collaboration with or under the direction of professional scientists and scientific institutions; an amateur scientist". The first use of the term "citizen scientist" can be found in the magazine New Scientist in an article about ufology from October 1979. Muki Haklay cites, from a policy report for the Wilson Center entitled "Citizen Science and Policy: A European Perspective", an alternate first use of the term "citizen science" by R. Kerson in the magazine MIT Technology Review from January 1989. Quoting from the Wilson Center report: "The new form of engagement in science received the name 'citizen science'. The first recorded example of the use of the term is from 1989, describing how 225 volunteers across the US collected rain samples to assist the Audubon Society in an acid-rain awareness raising campaign."
A Green Paper on Citizen Science was published in 2013 by the European Commission's Digital Science Unit and Socientize.eu, which included a definition for citizen science, referring to "the general public engagement in scientific research activities when citizens actively contribute to science either with their intellectual effort or surrounding knowledge or with their tools and resources. Participants provide experimental data and facilities for researchers, raise new questions and co-create a new scientific culture." Citizen science may be performed by individuals, teams, or networks of volunteers. Citizen scientists often partner with professional scientists to achieve common goals. Large volunteer networks often allow scientists to accomplish tasks that would be too expensive or time-consuming to accomplish through other means. Many citizen-science projects serve education and outreach goals. These projects may be designed for a formal classroom environment or an informal education environment such as museums. Citizen science has evolved over the past four decades. Recent projects place more emphasis on scientifically sound practices and measurable goals for public education. Modern citizen science differs from its historical forms primarily in the access for, and subsequent scale of, public participation; technology is credited as one of the main drivers of the recent explosion of citizen science activity. In March 2015, the Office of Science and Technology Policy published a factsheet entitled "Empowering Students and Others through Citizen Science and Crowdsourcing". Quoting: "Citizen science and crowdsourcing projects are powerful tools for providing students with skills needed to excel in science, technology, engineering, and math (STEM). Volunteers in citizen science, for example, gain hands-on experience doing real science, and in many cases take that learning outside of the traditional classroom setting". The National Academies of Science cites SciStarter as a platform offering access to more than 2,700 citizen science projects and events, as well as helping interested parties access tools that facilitate project participation.
In May 2016, a new open-access journal was started by the Citizen Science Association along with Ubiquity Press called Citizen Science: Theory and Practice (CS:T&P). Quoting from the editorial article titled "The Theory and Practice of Citizen Science: Launching a New Journal", "CS:T&P provides the space to enhance the quality and impact of citizen science efforts by deeply exploring the citizen science concept in all its forms and across disciplines. By examining, critiquing, and sharing findings across a variety of citizen science endeavors, we can dig into the underpinnings and assumptions of citizen science and critically analyze its practice and outcomes." In February 2020, Timber Press, an imprint of Workman Publishing Company, published The Field Guide to Citizen Science as a practical guide for anyone interested in getting started with citizen science.
Alternative definitions Other definitions for citizen science have also been proposed. For example, Bruce Lewenstein of Cornell University's Communication and S&TS departments describes three possible definitions:
The participation of nonscientists in the process of gathering data according to specific scientific protocols and in the process of using and interpreting that data. The engagement of nonscientists in true decision-making about policy issues that have technical or scientific components. The engagement of research scientists in the democratic and policy process. Scientists and scholars who have used other definitions include Frank N. von Hippel, Stephen Schneider, Neal Lane and Jon Beckwith. Other alternative terminologies proposed are "civic science" and "civic scientist". Some researchers suggested terms for citizen science extending to other realms: citizen science projects enabling participants to become "agents of policy change", for example in climate policy, could be called citizen social science. A 2014 Mashable article defines a citizen scientist as: "Anybody who voluntarily contributes his or her time and resources toward scientific research in partnership with professional scientists." In 2016, the Australian Citizen Science Association released their definition, which states "Citizen science involves public participation and collaboration in scientific research with the aim to increase scientific knowledge." In 2020, a group of birders in the Pacific Northwest of North America, eBird Northwest, has sought to rename "citizen science" to the use of "community science", "largely to avoid using the word 'citizen' when we want to be inclusive and welcoming to any birder or person who wants to learn more about bird watching, regardless of their citizen status."
Typologies of citizen science Citizen science initiatives are commonly categorized according to the level of involvement of the citizen scientists. Towards the lower end of involvement, terms such as crowdsourcing or contributory citizen science describe that citizen scientists contribute observations, collect data or merely offer computing power or install sensors to measure environmental variables. Towards the higher end of involvement, "extreme citizen science" and co-creation are terms used to describe initiatives in which citizen scientists are involved in decisions influencing the goal and research methods or even lead research initiatives.
Related fields In a Smart City era, Citizen Science relies on various web-based tools, such as WebGIS, and becomes Cyber Citizen Science. Some projects, such as SETI@home, use the Internet to take advantage of distributed computing. These projects are generally passive. Computation tasks are performed by volunteers' computers and require little involvement beyond initial setup. There is disagreement as to whether these projects should be classified as citizen science. The astrophysicist and Galaxy Zoo co-founder Kevin Schawinski stated: "We prefer to call this [Galaxy Zoo] citizen science because it's a better description of what you're doing; you're a regular citizen but you're doing science. Crowd sourcing sounds a bit like, well, you're just a member of the crowd and you're not; you're our collaborator. You're pro-actively involved in the process of science by participating." Compared to SETI@home, "Galaxy Zoo volunteers do real work. They're not just passively running something on their computer and hoping that they'll be the first person to find aliens. They have a stake in science that comes out of it, which means that they are now interested in what we do with it, and what we find." Citizen policy may be another result of citizen science initiatives. Bethany Brookshire (pen name SciCurious) writes: "If citizens are going to live with the benefits or potential consequences of science (as the vast majority of them will), it's incredibly important to make sure that they are not only well informed about changes and advances in science and technology, but that they also ... are able to ... influence the science policy decisions that could impact their lives." In "The Rightful Place of Science: Citizen Science", editors Darlene Cavalier and Eric Kennedy highlight emerging connections between citizen science, civic science, and participatory technology assessment.
Benefits and limitations The general public's involvement in scientific projects has become a means of encouraging curiosity and greater understanding of science while providing an unprecedented engagement between professional scientists and the general public. In a research report published by the U.S. National Park Service in 2008, Brett Amy Thelen and Rachel K. Thiet mention the following concerns, previously reported in the literature, about the validity of volunteer-generated data:
Some projects may not be suitable for volunteers, for instance, when they use complex research methods or require a great deal of (often repetitive) work. If volunteers lack proper training in research and monitoring protocols, the data they collect might introduce bias into the dataset. The question of data accuracy, in particular, remains open. John Losey, who created the Lost Ladybug citizen science project, has argued that the cost-effectiveness of citizen science data can outweigh data quality issues, if properly managed. In December 2016, authors M. Kosmala, A. Wiggins, A. Swanson and B. Simmons published a study in the journal Frontiers in Ecology and the Environment called "Assessing Data Quality in Citizen Science". The abstract describes how ecological and environmental citizen science projects have enormous potential to advance science. Citizen science projects can influence policy and guide resource management by producing datasets that are otherwise not feasible to generate. In the section "In a Nutshell" (pg3), four condensed conclusions are stated. They are:
They conclude that as citizen science continues to grow and mature, a key metric of project success they expect to see will be a growing awareness of data quality. They also conclude that citizen science will emerge as a general tool helping "to collect otherwise unobtainable high-quality data in support of policy and resource management, conservation monitoring, and basic science." A study of Canadian lepidoptera datasets published in 2018 compared the use of a professionally curated dataset of butterfly specimen records with four years of data from a citizen science program, eButterfly. The eButterfly dataset was used as it was determined to be of high quality because of the expert vetting process used on site, and there already existed a dataset covering the same geographic area consisting of specimen data, much of it institutional. The authors note that, in this case, citizen science data provides both novel and complementary information to the specimen data. Five new species were reported from the citizen science data, and geographic distribution information was improved for over 80% of species in the combined dataset when citizen science data was included. Several recent studies have begun to explore the accuracy of citizen science projects and how to predict accuracy based on variables like expertise of practitioners. One example is a 2021 study by Edgar Santos-Fernandez and Kerrie Mengersen of the British Ecological Society, who utilized a case study which used recent R and Stan programming software to offer ratings of the accuracy of species identifications performed by citizen scientists in Serengeti National Park, Tanzania. This provided insight into possible problems with processes like this which include, "discriminatory power and guessing behaviour". The researchers determined that methods for rating the citizen scientists themselves based on skill level and expertise might make studies they conduct more easy to analyze. Studies that are simple in execution are where citizen science excels, particularly in the field of conservation biology and ecology. For example, in 2019, Sumner et al. compared the data of vespid wasp distributions collected by citizen scientists with the 4-decade, long-term dataset established by the BWARS. They set up the Big Wasp Survey from 26 August to 10 September 2017, inviting citizen scientists to trap wasps and send them for identification by experts where data was recorded. The results of this study showed that the campaign garnered over 2,000 citizen scientists participating in data collection, identifying over 6,600 wasps. This experiment provides strong evidence that citizen science can generate potentially high-quality data comparable to that of expert data collection, within a shorter time frame. Although the experiment was to originally test the strength of citizen science, the team also learned more about Vespidae biology and species distribution in the United Kingdom. With this study, the simple procedure enabled citizen science to be executed in a successful manner. A study by J. Cohn describes that volunteers can be trained to use equipment and process data, especially considering that a large proportion of citizen scientists are individuals who are already well-versed in the field of science. The demographics of participants in citizen science projects are overwhelmingly White adults, of above-average income, having a university degree. Other groups of volunteers include conservationists, outdoor enthusiasts, and amateur scientists. As such, citizen scientists are generally individuals with a pre-understanding of the scientific method and how to conduct sensible and just scientific analysis. Some citizen science initiatives specifically work inclusively, investigating aspects of social inclusion and cohesion and conducted, for example, projects with hard of hearing young people.
Ethics Various studies have been published that explore the ethics of citizen science, including issues such as intellectual property and project design.(e.g.) The Citizen Science Association (CSA), based at the Cornell Lab of Ornithology, and the European Citizen Science Association (ECSA), based in the Museum für Naturkunde in Berlin, have working groups on ethics and principles. In September 2015, ECSA published its Ten Principles of Citizen Science, which have been developed by the "Sharing best practice and building capacity" working group of ECSA, led by the Natural History Museum, London with input from many members of the association.
The medical ethics of internet crowdsourcing has been questioned by Graber & Graber in the Journal of Medical Ethics. In particular, they analyse the effect of games and the crowdsourcing project Foldit. They conclude: "games can have possible adverse effects, and that they manipulate the user into participation". In March 2019, the online journal Citizen Science: Theory and Practice launched a collection of articles on the theme of Ethical Issues in Citizen Science. The articles are introduced with (quoting): "Citizen science can challenge existing ethical norms because it falls outside of customary methods of ensuring that research is conducted ethically. What ethical issues arise when engaging the public in research? How have these issues been addressed, and how should they be addressed in the future?" In June 2019, East Asian Science, Technology and Society: An International Journal (EASTS) published an issue titled "Citizen Science: Practices and Problems" which contains 15 articles/studies on citizen science, including many relevant subjects of which ethics is one. Quoting from the introduction "Citizen, Science, and Citizen Science": "The term citizen science has become very popular among scholars as well as the general public, and, given its growing presence in East Asia, it is perhaps not a moment too soon to have a special issue of EASTS on the topic." Use of citizen science volunteers as de facto unpaid laborers by some commercial ventures have been criticized as exploitative. Ethics in citizen science in the health and welfare field, has been discussed in terms of protection versus participation. Public involvement researcher Kristin Liabo writes that health researcher might, in light of their ethics training, be inclined to exclude vulnerable individuals from participation, to protect them from harm. However, she argues these groups are already likely to be excluded from participation in other arenas, and that participation can be empowering and a possibility to gain life skills that these individuals need. Whether or not to become involved should be a decision these individuals should be involved in and not a researcher decision. In July 2026, the study "10 recommendations for strengthening citizen science for improved societal and ecological outcomes: A co-produced analysis of challenges and opportunities in the 21st century" was published. The study "explores how citizen science can be improved by involving the public in all stages of scientific research" and concludes by arguing that "as the world confronts climate change, public health crises, and biodiversity loss, broader public involvement in science is key for equitable, efficient and evidence-informed responses."
Data governance, privacy and sovereignty As citizen science becomes increasingly influenced by digital platforms and sensors, governance questions go beyond research ethics to include data protection law and community control over reuse. Under the General Data Protection Regulation (GDPR), participatory projects that involve personal data can complicate the usual separation between professional researchers ("controllers") and participants ("data subjects"): citizen scientists may be considered joint controllers when they share or shape project purposes, which could expose volunteers to compliance responsibilities and create risks for both participant protections and project legitimacy. Practical guidance for citizen science therefore increasingly requires early planning for lawful data handling, clear allocation of responsibilities, and transparency about data flows across collection, storage, and sharing. A second governance challenge concerns power asymmetries in open data. Because volunteers often produce data while institutions handle and publish it, decisions about openness, attribution, and access restrictions can include unequal priorities and certain vulnerabilities. Ethical open-data practice in citizen science is therefore frequently framed as a matter of data governance, not only technical quality. These concerns also extend to environmental monitoring where data may be politically sensitive (e.g., pollution exposure, land use, biodiversity decline). Finally, monitoring initiatives have highlighted data sovereignty: the principle that indigenous peoples and local communities should govern collection, ownership, access and use of data connected to territories and cultural knowledge; so that digital monitoring does not reproduce colonialist tendencies between knowledge holders and external institutions. Related international policy discussions on open science explicitly point out that openness should not overrule privacy, equity, or indigenous rights over traditional knowledge.
Economic worth In the research paper "Can citizen science enhance public understanding of science?" by Bonney et al. 2016, statistics which analyse the economic worth of citizen science are used, drawn from two papers: i) Sauermann and Franzoni 2015, and ii) Theobald et al. 2015. In "Crowd science user contribution patterns and their implications" by Sauermann and Franzoni (2015), seven projects from the Zooniverse web portal are used to estimate the monetary value of the citizen science that had taken place. The seven projects are: Solar Stormwatch, Galaxy Zoo Supernovae, Galaxy Zoo Hubble, Moon Zoo, Old Weather, The Milky Way Project and Planet Hunters. Using data from 180 days in 2010, they find a total of 100,386 users participated, contributing 129,540 hours of unpaid work. Estimating at a rate of $12 an hour (an undergraduate research assistant's basic wage), the total contributions amount to $1,554,474, an average of $222,068 per project. The range over the seven projects was from $22,717 to $654,130. In "Global change and local solutions: Tapping the unrealized potential of citizen science for biodiversity research" by Theobald et al. 2015, the authors surveyed 388 unique biodiversity-based projects. Quoting: "We estimate that between 1.36 million and 2.28 million people volunteer annually in the 388 projects we surveyed, though variation is great" and that "the range of in-kind contribution of the volunteerism in our 388 citizen science projects as between $667 million to $2.5 billion annually." Worldwide participation in citizen science continues to grow. A list of the top five citizen science communities compiled by Marc Kuchner and Kristen Erickson in July 2018 shows a total of 3.75 million participants, although there is likely substantial overlap between the communities.
Relations with education and academia There have been studies published which examine the place of citizen science within education.(e.g.) Teaching aids can include books and activity or lesson plans.(e.g.). Some examples of studies are: From the Second International Handbook of Science Education, a chapter entitled: "Citizen Science, Ecojustice, and Science Education: Rethinking an Education from Nowhere", by Mueller and Tippins (2011), acknowledges in the abstract that: "There is an emerging emphasis in science education on engaging youth in citizen science." The authors also ask: "whether citizen science goes further with respect to citizen development." The abstract ends by stating that the "chapter takes account of the ways educators will collaborate with members of the community to effectively guide decisions, which offers promise for sharing a responsibility for democratizing science with others." From the journal Democracy and Education, an article entitled: "Lessons Learned from Citizen Science in the Classroom" by authors Gray, Nicosia and Jordan (GNJ; 2012) gives a response to a study by Mueller, Tippins and Bryan (MTB) called "The Future of Citizen Science". GNJ begins by stating in the abstract that "The Future of Citizen Science": "provides an important theoretical perspective about the future of democratized science and K12 education." But GRB state: "However, the authors (MTB) fail to adequately address the existing barriers and constraints to moving community-based science into the classroom." They end the abstract by arguing: "that the resource constraints of scientists, teachers, and students likely pose problems to moving true democratized science into the classroom." In 2014, a study was published called "Citizen Science and Lifelong Learning" by R. Edwards in the journal Studies in the Education of Adults. Edwards begins by writing in the abstract that citizen science projects have expanded over recent years and engaged citizen scientists and professionals in diverse ways. He continues: "Yet there has been little educational exploration of such projects to date." He describes that "there has been limited exploration of the educational backgrounds of adult contributors to citizen science". Edwards explains that citizen science contributors are referred to as volunteers, citizens or as amateurs. He ends the abstract: "The article will explore the nature and significance of these different characterisations and also suggest possibilities for further research." In the journal Microbiology and Biology Education a study was published by Shah and Martinez (2015) called "Current Approaches in Implementing Citizen Science in the Classroom". They begin by writing in the abstract that citizen science is a partnership between inexperienced amateurs and trained scientists. The authors continue: "With recent studies showing a weakening in scientific competency of American students, incorporating citizen science initiatives in the curriculum provides a means to address deficiencies". They argue that combining traditional and innovative methods can help provide a practical experience of science. The abstract ends: "Citizen science can be used to emphasize the recognition and use of systematic approaches to solve problems affecting the community." In November 2017, authors Mitchell, Triska and Liberatore published a study in PLOS One titled "Benefits and Challenges of Incorporating Citizen Science into University Education". The authors begin by stating in the abstract that citizen scientists contribute data with the expectation that it will be used. It reports that citizen science has been used for first year university students as a means to experience research. They continue: "Surveys of more than 1500 students showed that their environmental engagement increased significantly after participating in data collection and data analysis." However, only a third of students agreed that data collected by citizen scientists was reliable. A positive outcome of this was that the students were more careful of their own research. The abstract ends: "If true for citizen scientists in general, enabling participants as well as scientists to analyse data could enhance data quality, and so address a key constraint of broad-scale citizen science programs." Citizen science has also been described as challenging the "traditional hierarchies and structures of knowledge creation".
History While citizen science developed at the end of the 20th century, characteristics of citizen science are not new. Prior to the 20th century, science was often the pursuit of gentleman scientists, amateur or self-funded researchers such as Sir Isaac Newton, Benjamin Franklin, and Charles Darwin. Women citizen scientists from before the 20th century include Florence Nightingale who "perhaps better embodies the radical spirit of citizen science". Before the professionalization of science by the end of the 19th century, most pursued scientific projects as an activity rather than a profession itself, an example being amateur naturalists in the 18th and 19th centuries. During the British colonization of North America, American Colonists recorded the weather, offering much of the information now used to estimate climate data and climate change during this time period. These people included John Campanius Holm, who recorded storms in the mid-1600s, as well as George Washington, Thomas Jefferson, and Benjamin Franklin who tracked weather patterns during America's founding. Their work focused on identifying patterns by amassing their data and that of their peers and predecessors, rather than specific professional knowledge in scientific fields. Some consider these individuals as the progenitors of the citizen scientist concept, while others ascribe this designation to prominent figures such as Leonardo da Vinci and Charles Darwin. However, there are also those who perceive citizen science as a distinct movement that developed later on, building on the preceding history of science. However, by the mid-20th century, the scientific community was dominated by researchers employed by universities and government research laboratories. By the 1970s, this transformation was being called into question. Philosopher Paul Feyerabend called for a "democratization of science". Biochemist Erwin Chargaff advocated a return to science by nature-loving amateurs in the tradition of Descartes, Newton, Leibniz, Buffon, and Darwin. This approach would prioritize the contributions of "amateurship instead of money-biased technical bureaucrats". A 2016 study indicates that the largest impact of citizen science is evident in research domains such as biology, conservation, and ecology. The primary utilization of citizen science is as a methodology for data collection and classification.
Amateur astronomy
Astronomy has long been a field where amateurs have contributed throughout time, all the way up to the present day. Collectively, amateur astronomers observe a variety of celestial objects and phenomena sometimes with equipment that they build themselves. Common targets of amateur astronomers include the Moon, planets, stars, comets, meteor showers, and a variety of deep-sky objects such as star clusters, galaxies, and nebulae. Observations of comets and stars are also used to measure the local level of artificial skyglow. One branch of amateur astronomy, amateur astrophotography, involves the taking of photos of the night sky. Many amateurs like to specialize in the observation of particular objects, types of objects, or types of events that interest them. The American Association of Variable Star Observers has gathered data on variable stars for educational and professional analysis since 1911 and promotes participation beyond its membership on its Citizen Sky website. Project PoSSUM is a relatively new organization, started in March 2012, which trains citizen scientists of many ages to go on polar suborbital missions. On these missions, they study noctilucent clouds with remote sensing, which reveals interesting clues about changes in the upper atmosphere and the ozone due to climate change. This is a form of citizen science which trains younger generations to be ambitious, participating in intriguing astronomy and climate change science projects even without a professional degree.
Butterfly counts
Butterfly counts have a long tradition of involving individuals in the study of butterflies' range and their relative abundance. Two long-running programs are the UK Butterfly Monitoring Scheme (started in 1976) and the North American Butterfly Association's Butterfly Count Program (started in 1975). There are various protocols for monitoring butterflies and different organizations support one or more of transects, counts and/or opportunistic sightings. eButterfly is an example of a program designed to capture any of the three types of counts for observers in North America. Species-specific programs also exist, with monarchs the prominent example. Two examples of this involve the counting of monarch butterflies during the fall migration to overwintering sites in Mexico: (1) Monarch Watch is a continent-wide project, while (2) the Cape May Monarch Monitoring Project is an example of a local project.
Ornithology
Citizen science projects have become increasingly focused on providing benefits to scientific research. The North American Bird Phenology Program (historically called the Bird Migration and Distribution records) may have been the earliest collective effort of citizens collecting ornithological information in the U.S. The program, dating back to 1883, was started by Wells Woodbridge Cooke. Cooke established a network of observers around North America to collect bird migration records. The Audubon Society's Christmas Bird Count, which began in 1900, is another example of a long-standing tradition of citizen science which has persisted to the present day, now containing a collection of six million handwritten migration observer cards that date back to the 19th century. Participants input this data into an online database for analysis. Citizen scientists help gather data that will be analyzed by professional researchers, and can be used to produce bird population and biodiversity indicators. Raptor migration research relies on the data collected by the hawkwatching community. This mostly volunteer group counts migrating accipiters, buteos, falcons, harriers, kites, eagles, osprey, vultures and other raptors at hawk sites throughout North America during the spring and fall seasons. The daily data is uploaded to hawkcount.org where it can be viewed by professional scientists and the public. Other programs in North America include Project FeederWatch, which is affiliated with the Cornell Lab of Ornithology. Such indices can be useful tools to inform management, resource allocation, policy and planning. For example, European breeding bird survey data provide input for the Farmland Bird Index, adopted by the European Union as a structural indicator of sustainable development. This provides a cost-effective alternative to government monitoring. Similarly, data collected by citizen scientists as part of BirdLife Australia's has been analysed to produce the first-ever Australian Terrestrial Bird Indices. In the UK, the Royal Society for the Protection of Birds collaborated with a children's TV show to create a national birdwatching day in 1979; the campaign has continued for over 40 years and in 2024, over 600,000 people counted almost 10 million birds during the Big Garden Birdwatch weekend. Most recently, more programs have sprung up worldwide. One such program is NestWatch, a bird species monitoring program which tracks data on reproduction. This might include studies on when and how often nesting occurs, counting eggs laid and how many hatch successfully, and what proportion of hatchlings survive infancy. Participation in this program is intended to be easy for the general public. Using the recently created NestWatch app, anyone is able to begin to observe their local species, recording results every 3 to 4 days within the app. This forms a continually-growing database which researchers can view and utilize to understand trends within specific bird populations.
Citizen oceanography The concept of citizen science has been extended to the ocean environment for characterizing ocean dynamics and tracking marine debris. For example, the mobile app Marine Debris Tracker is a joint partnership of National Oceanic and Atmospheric Administration and the University of Georgia. Long term sampling efforts such as the continuous plankton recorder has been fitted on ships of opportunity since 1931. Plankton collection by sailors and subsequent genetic analysis was pioneered in 2013 by Indigo V Expeditions as a way to better understand marine microbial structure and function.
Coral reefs Citizen science in coral reef studies developed in the 21st century. Underwater photography has become more popular since the development of moderate priced digital cameras with waterproof housings in the early 2000s, resulting on millions of pictures posted every year on various websites and social media. This mass of documentation has great scientific potential, as millions of tourists possess a much superior coverage power than professional scientists, who cannot spend so much time in the field. As a consequence, several participative sciences programs have been developed, supported by geotagging and identification web sites such as iNaturalist. The Monitoring through many eyes project collates thousands of underwater images of the Great Barrier Reef and provides an interface for elicitation of reef health indicators. The National Oceanic and Atmospheric Administration (NOAA) also offers opportunities for volunteer participation. By taking measurements in The United States' National Marine Sanctuaries, citizens contribute data to marine biology projects. In 2016, NOAA benefited from 137,000 hours of research. There also exist protocols for auto-organization and self-teaching aimed at biodiversity-interested sn