Monitoring the world's bird populations with community science data (original) (raw)
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Using opportunistic citizen science data to estimate avian population trends
Determining population trends is critical for conservation. For most bird species, trends are based on count data gathered by institutions with formalized survey protocols. However, limited resources may prevent these types of surveys, especially in developing countries. Ecotourism growth and subsequent increases in opportunistic data from birdwatching can provide a source of population trend information if analyses control for inter-observer variation. List length analysis (LLA) controls for such variation by using the number of species recorded as a proxy for observer skill and effort. Here, we use LLA on opportunistic data gathered by eBird to estimate population trends for 574 North American bird species (48% of species declining) and compare these estimates to population trends based on 1) formal breeding bird surveys (54% of species declining) and 2) population estimates from eBird data controlled using more rigorous correction (46% of species declining). Our analyses show that eBird data produce population trends that differ on average by only 0.4%/year from formal surveys and do not differ significantly from estimates using more control metrics. We find that estimates do not improve appreciably beyond 10,000 checklists, suggesting this as the minimum threshold of opportunistic data required for population trend estimation. Lastly, we show that characteristics affecting a species' ubiquity, such as geographic and elevational range, can affect its population trend estimate. Our results suggest that opportunistic data can be used to approximate species population trends, especially for widespread species. Because our protocol uses information present in all checklists, it can be applied to a diversity of data sources including eBird, trip reports, and bird atlases. (J.J. Horns). Biological Conservation 221 (2018) 151-159 0006-3207/
PLOS ONE, 2021
Biodiversity loss is a global ecological crisis that is both a driver of and response to environmental change. Understanding the connections between species declines and other components of human-natural systems extends across the physical, life, and social sciences. From an analysis perspective, this requires integration of data from different scientific domains, which often have heterogeneous scales and resolutions. Community science projects such as eBird may help to fill spatiotemporal gaps and enhance the resolution of standardized biological surveys. Comparisons between eBird and the more comprehensive North American Breeding Bird Survey (BBS) have found these datasets can produce consistent multi-year abundance trends for bird populations at national and regional scales. Here we investigate the reliability of these datasets for estimating patterns at finer resolutions, inter-annual changes in abundance within town boundaries. Using a case study of 14 focal species within Mass...
Journal of Ornithology
Local biodiversity monitoring is important to assess the effects of global change, but also to evaluate the performance of landscape and wildlife protection, since large-scale assessments may buffer local fluctuations, rare species tend to be underrepresented, and management actions are usually implemented on local scales. We estimated population trends of 58 bird species using open-population N-mixture models based on count data in two localities in southeastern Spain, which have been collected according to a citizen science monitoring program (SACRE, Monitoring Common Breeding Birds in Spain) over 21 and 15 years, respectively. We performed different abundance models for each species and study area, accounting for imperfect detection of individuals in replicated counts. After selecting the best models for each species and study area, empirical Bayes methods were used for estimating abundances, which allowed us to calculate population growth rates (λ) and finally population trends....
Long-term, locally-based biodiversity monitoring programs are essential for understanding and mitigating the effects of global change on tropical biodiversity while providing capacity-building, environmental education, and public outreach. However, these programs are lacking in most tropical countries. Birds are the best-known major group of organism, comprise excellent environmental indicators, are relatively easy to monitor, and are met with enthusiasm and interest by people worldwide. Bird monitoring programs using mist nets and bird banding (ringing) are especially valuable, as these well-established techniques enable the use of capture-mark-recapture (CMR) models to measure population change and other demographic parameters. Equally important for conservation, the ability to capture and release birds makes it possible to provide hands-on ornithological training and educational activities to students, conservationists, villagers, decision-makers, journalists, and other local people. Bird banding programs provide local jobs for research assistants, who often go on to productive careers in conservation, education, research, or ecotourism. Long-term bird banding stations also provide the nuclei, infrastructure, and staff for monitoring, education, and conservation programs focused on other taxa. As successful examples from Costa Rica and Ethiopia show, bird monitoring programs that integrate conservation, ecological research, environmental education, capacity-building, and income generation are cost-effective tools to achieve the goals of community-based biodiversity conservation and poverty reduction in the developing world. Therefore, locally-based and long-term bird monitoring programs should be encouraged, established, and funded throughout the tropics
protocols.io, 2019
Ba ckground Ba ckground Due to certain risk factors such as climate change, habitat destruction, overhunting and pollution bird extinctions are now occurring at a rate that far exceeds their speciation rate. When a bird species is lost, the benefits it might have afforded are gone forever. There are no robust indicators of biodiversity conservation that can be used to complement existing national indicators of economic and social health. This study reviews the statistical methods that are used to model and evaluate the persistence or extinction risk of threatened bird species using citizen science data. Me thods Me thods Adhering to PRISMA guidelines, this review systematically searched for relevant journal articles which were published between January 1900 and January 2019 in any of three databases (ProQuest Central, Scopus and Web of Science). Only the journal articles which used a statistical model, predictive model or trend analysis in analysing persistence or extinction risk (while considering risk factors) of threatened bird species developed using citizen science data were included in this study. The bird species that may be declining in population/range even in near threatened or least concern categories also included since these may be the next wave of species to be added to the endangered species lists. Citizen science data helps to increase the number of records and understanding of dynamics in declining bird species populations. Re sul ts Re sul ts This systematic review was able to identify 37 unique articles describing statistical models for this purpose. Generalised linear models and linear mixed/hierarchical models were the most popular methods used for analysis, followed by machine learning models. The review suggested several strategies to measure the persistence of threatened bird species, but there was no attempt to identify critical tipping points using methods such as changepoint analysis. Concl usi on Concl usi on Overall, it appears that the persistence of threatened bird species varies depending on various risk factors. Statistical models can provide a better understanding of the impact of these risk factors, which is expected to produce better immediate and long-term outcomes for the conservation of threatened birds. It is hoped that this review will identify the statistical methods which are most suitable for this purpose.
Comparing avian species richness estimates from structured and semi-structured citizen science data
Scientific Reports, 2023
Citizen science, including structured and semi-structured forms, has become a powerful tool to collect biodiversity data. However, semi-structured citizen science data have been criticized for higher variability in quality, including less information to adjust for imperfect detection and uneven duration that bias the estimates of species richness. Species richness estimators may quantify bias in estimates. Here, we test the effectiveness of Chao1 estimator in eBird (semi-structured) by comparing it to averaged species richness in Breeding Bird Survey Taiwan, BBS (structured) and quantifying bias. We then fit a power function to compare bias while controlling for differences in count duration. The Chao1 estimator increased the species richness estimates of eBird data from 56 to 69% of the average observed BBS and from 47 to 59% of the average estimated BBS. Effects of incomplete short duration samples and variability in detectability skills of observers can lead to biased estimates. Using the Chao1 estimator improved estimates of species richness from semi-structured and structured data, but the strong effect of singleton species on bias, especially in short duration counts, should be evaluated in advance to reduce the uncertainty of estimation processes. Biodiversity loss impacts ecosystem services and ecosystem functions worldwide 1. Most recently, the loss of biodiversity has been driven by climate change, habitat conversion and fragmentation, and introduction of invasive species 2-5. Under these impacts, it has become crucial for scientists to develop methods to monitor biodiversity across different temporal and spatial scales. Species richness, one of the most common measures of biodiversity, is defined as the number of species in a given area 6,7. Unfortunately, monitoring species richness is well known for being expensive and labor-intensive, and often beyond the means of modestly funded research studies. In contrast, citizen science has recently emerged as an alternative that provides a low-cost approach to collect species richness data. Citizen science projects invite volunteers to participate in and contribute observations for scientific purposes 8. One of the biggest advantages of citizen science projects is that it generates a large number of observations, which often involve documenting species richness and species composition. Citizen science can be grouped into three main categories: structured, semi-structured, and unstructured citizen science 9. Structured citizen science adheres to a rigorous data collection methodology and aims to produce higher quality data, by standardizing the quality of observations from volunteer training, survey duration, and choice of sampling locations 6. Despite the higher quality output from structured citizen science programs, such as Breeding Bird Survey Taiwan (BBS), acquiring such data is not timely in most cases, because some observations need to be organized and validated before release to public. On the other hand, semi-structured citizen science usually provides options for observers to collect information 9 and users can immediately access information. Semi-structured citizen science projects such as eBird usually allow observers to survey without time or location restrictions and data can be contributed by observers of all skill levels 6. Yet, the abundant observations distributed across large spatial and temporal scales may be a strength of semi-structured citizen-science data. Unstructured citizen science has the least restriction regarding data collection methodology, such as iNaturalist 9. However, unstructured citizen science often lacks
Are two days enough? Checking accuracy of survey protocols used in common birds monitoring schemes
Ardeola, 2018
Common bird monitoring schemes have become an important tool in conservation biology because they provide useful information for assessing spatial and temporal variations of bird populations. However, recorded data may suffer from several observational procedures that cause error. In recent years, a robust mathematical framework has been developed to control for potential confounding factors affecting the assessment of the actual spatial and temporal variability of bird populations. Surprisingly few attempts have been made to check the effectiveness of current methodology empirically and thus to determine to what extent monitoring scheme data can provide accurate estimates of actual bird abundances. To check the effect of intra-annual variability of bird counts, I conducted daily surveys of House Martin Delichon urbicum and Common Swift Apus apus populations along a 2-km transect line in Tres Cantos (Madrid, Spain) between March and September 2005. The data recorded perfectly mimicked the information collected every spring by observers participating in the common bird monitoring schemes of Spain. Computer simulations with my data showed that the probability of recording the actual annual maximum of individual numbers was less than 9% by the available protocols. Simulations of protocols with increased survey frequency demonstrated that three or four surveys per year would be enough to increase the accuracy of recorded House Martin abundance significantly. However, at least weekly surveys in spring would be required to produce acceptable annual estimates of the abundance of the Common Swift. My results suggest that two surveys per spring are not enough in the studied species, due to the huge between-day variability of records. Such variability is primarily caused by the nature of the count data and the seasonal patterns of occurrence/ detectability of individuals. Abundance data for swifts and house martins recorded in common bird monitoring schemes should thus be used cautiously due to its potential inaccurary. Key words: abundance, Apus apus, citizen science, Delichon urbicum, line-transect, population, Spain.
French citizens monitoring ordinary birds provide tools for conservation and ecological sciences
Acta Oecologica, 2012
Volunteer-based standardized monitoring of birds has been widely implemented in Europe and North America. In France, a breeding bird survey is running since 1989 and offers keen birdwatchers to count spring birds annually during 5 min exactly on 10 fix points within a randomly selected square. The first goal of such breeding bird surveys is to measure temporal trends in order to detect possible species declines. Combining annual indices of species sharing ecological affinities or a protected/red list status further provides biodiversity indicators for policy makers. Because the sampling effort is similar among sites, and because the initial selection of monitored sites is random, the temporal trends can be considered representative of national trends, and spatial comparisons of the obtained metrics are possible. Species abundance, community richness but also community specialization and average trophic level can be estimated for each site and each year and further related to the wide range of habitat and landscape characteristics and to agricultural or forestry practices. The large number of sites allows overcoming the opposition between adaptive and passive monitoring, making such schemes fitted to adaptive monitoring. This provides opportunities to determine which type of management or practices favour biodiversity. The comparison of population fate or community dynamics across a wide range of climates and temperatures, e.g. from southern to northern Europe, revealed how European birds are already affected by climate change. Bird communities are shifting northwards, but at a slower rate than temperatures, while bird populations have larger growth rates away from their hot thermal limit. Finally, such large-scale long-term monitoring data on a complete taxonomic group (Aves) is original and offers the opportunity to compare different measures of biological diversity, such as taxonomic, phylogenetic and functional diversity. Such a citizen science scheme is an efficient scientific tool (numerous papers published in international peer-reviewed journals) which is furthermore highly cost-effective, with a reduced permanent staff in a state insitution coordonating the network and analysing the data, while a similar survey conducted by state staff only would cost more than one million euros annually. The future development of bio-economic dynamic models for providing scenarios of sustainable farming and logging to maintain biodiversity will further highlight the necessity of such volunteer monitoring for policy makers and decision planning. Scientific and logistic partnerships could be proposed to help developing such a monitoring scheme in China.
In the northern hemisphere, bird counts have been fundamental in gathering data to understand population trends. Due to the seasonality of the northern hemisphere, counts take place during two clearly defined moments in time: the breeding season (resident birds) and winter (after migration). Depending on location, Neotropical birds may breed at any time of year, may or may not migrate, and those patterns are not necessarily synchronous among species. Also in contrast to the northern hemisphere, population trends and the impact of rapid urbanization and deforestation are unknown and unmonitored. Throughout one year, we used point counts to better understand temporal patterns of bird species richness and relative abundance in the state of São Paulo, southeastern Brazil, to examine how to implement similar bird counts in tropical America. We counted birds twice each day on 10 point transects (20 points day -1 ), separated by 200 m, with a 100 m limited detection radius in a semideciduous tropical forest. Both species richness and bird abundance were greater in the morning, but accumulation curves suggest that longer-duration afternoon counts would reach the same total species as in morning counts. Species richness and bird abundance did not vary seasonally and unique species were counted every month; relatively few species (20%) were present in all months. Most (84%) known forest species in the area were encountered. We suggest that point counts can work here as they do in the northern hemisphere. We recommend that transects include at least 20 points and that the simplest timing of bird counts would also be seasonal, using timing of migration of austral migrants (and six months later) to coordinate counts. We propose that bird counts in Brazil, and elsewhere in Latin America, would provide data to help understand population trends, but would require greater effort than in temperate latitudes due to greater species richness and different dynamics of reproduction and migration. With collaboration among ornithologists and coordinated bird surveys, we may develop a technique for the tropics that would yield information for population trends and conservation of birds, similar to counts in temperate latitudes.