iNaturalist accelerates biodiversity research

Abstract

Participatory citizen science is expanding, with iNaturalist emerging as one of the most widely used platforms globally. However, its application in research is often anecdotal. To evaluate the impact of how iNaturalist is contributing to biodiversity and conservation research, we conducted a systematic review of iNaturalist data use and compared our findings with Global Biodiversity Information Facility literature citing iNaturalist. We found that the use of iNaturalist data in peer-reviewed research has grown tenfold in the last 5 years, matching the growing increase in iNaturalist observations. Geographic and taxonomic representation in the literature generally aligns with data availability, with iNaturalist data derived from 128 countries and 638 taxonomic families being used in peer-reviewed literature. Currently, data from iNaturalist are primarily used for species distribution models and range dynamics. We highlight emerging trends in the use of iNaturalist data in the literature lending to its future potential across biodiversity sciences.

Keywords: GBIF; citizen science; community science; participatory science; review.

Figure 1.

Methods for obtaining iNaturalist literature, Global Biodiversity Information Facility (GBIF) literature, and iNaturalist observations. The right panel displays the focus areas of this study.

Figure 2.

Count of scientific articles that use iNaturalist data over time from (a) iNaturalist literature and (b) Global Biodiversity Information Facility (GBIF) literature compared with the (c) count of iNaturalist observations on the platform over time. All data are shown for the years 2015–2022, the period during which all sources had at least one article and for which a full year of data was available.

Figure 3.

Comparison of the proportion of iNaturalist-related literature articles to iNaturalist observations, shown as (a) a map and (b) a scatterplot. The literature articles were sourced from iNaturalist literature and Global Biodiversity Information Facility (GBIF) literature. Countries with fewer than five literature articles were excluded because of lower confidence in those estimates. In the map, the regions with fewer articles than expected on the basis of the proportion of observations are denoted by positive residual difference values, whereas those with more articles than expected are denoted by negative residual difference values. The scatterplot is displayed on a log scale for both the x- and y-axes. The solid line represents the linear trend between the proportion of articles and the proportion of iNaturalist observations, with the shaded area indicating the standard error. The dashed line represents a 1:1 relationship, where the proportions are equal. The countries below the dashed line are overrepresented in the literature and above the dashed line are underrepresented in the literature. Selected points of interest are labeled. See supplemental figure S2 for the geographic distribution of iNaturalist literature, GBIF literature, and iNaturalist observations as a function of the country and a scatterplot of the proportion of articles from iNaturalist and GBIF literature as a function of the proportion of iNaturalist observations for each country. For detailed country-level data, see supplemental table S2.

Figure 4.

Taxonomic distribution of articles from iNaturalist literature review, Global Biodiversity Information Facility (GBIF) literature, and iNaturalist observations by kingdom (star symbol) and class (circle symbol) for Animalia and Plantae. Displayed are the groups that appeared in more than 5% of the articles in both literature data sets. The grey dashed line represents a 1:1 relationship, where taxonomic groups below the line are overrepresented in the literature and where those above the line are underrepresented in the literature. See supplemental figure S3 for bar plots of the proportion of each taxonomic group for each data source: iNaturalist literature, GBIF literature, and iNaturalist observations.

Figure 5.

(a) The proportion of topics discussed in the literature from iNaturalist literature. The data are displayed from 2016 onward, when there were more than 15 articles represented in the iNaturalist literature review. In addition, the figure displays a (b) word cloud using unique titles from both the literature review and Global Biodiversity Information Facility literature. The larger words represent text that was more common in literature titles.

Figure 6.

The count of articles grouped by (a) analyses conducted using iNaturalist data, (b) iNaturalist data type, and (c) iNaturalist data role in iNaturalist literature review papers. One article may fall into multiple categories of analysis type and data type. The proportion of articles using (d) imagery analysis and (e) imagery data type over time is displayed, as imagery showed the strongest trend among the categories examined (figure S6).