Continent‐scale phenotype mapping using citizen scientists’ photographs

Abstract

Field investigations of phenotypic variation in free‐living organisms are often limited in scope owing to time and funding constraints. By collaborating with online communities of amateur naturalists, investigators can greatly increase the amount and diversity of phenotypic data in their analyses while simultaneously engaging with a public audience. Here, we present a method for quantifying phenotypes of individual organisms in citizen scientists’ photographs. We then show that our protocol for measuring wing phenotypes from photographs yields accurate measurements in two species of Calopterygid damselflies. Next, we show that, while most observations of our target species were made by members of the large and established community of amateur naturalists at http://iNaturalist.org, our efforts to increase recruitment through various outreach initiatives were successful. Finally, we present results from two case studies: 1) an analysis of wing pigmentation in male smoky rubyspots Hetaerina titia showing previously undocumented geographical variation in a seasonal polyphenism, and 2) an analysis of variation in the relative size of the wing spots of male banded demoiselles Calopteryx splendens in Great Britain questioning previously documented evidence for character displacement. Our results demonstrate that our protocol can be used to create high quality phenotypic datasets using citizen scientists’ photographs, and, when combined with metadata (e.g. date and location), can greatly broaden the scope of studies of geographical and temporal variation in phenotypes. Our analyses of the recruitment and engagement process also demonstrate that collaborating with an online community of amateur naturalists can be a powerful way to conduct hypothesis‐driven research aiming to elucidate the processes that impact trait evolution at landscape scales.

Citizen science reveals the distribution of the invasive harlequin ladybird (Harmonia axyridis Pallas) in Argentina

“…Citizen science open data platforms have shown to be a valuable source of records of many types of organisms for many fields of research. For instance, data available in these platforms have been used to generate models to understand current and future distribution and status of plants and animals (Chardon et al 2015;Outhwaite et al 2019), to analyse phenotypic variation of insect species (Drury et al 2019), and to bolster museum collections data of native and invasive reptiles and amphibians particularly from urban and suburban areas (Spear et al 2017) among many other cases. Distribution of H. axyridis in Argentina Taking this project and Ecoregistros records together, H. axyridis in Argentina seems to extend from at least 24°to 43°S and from 71°30 0 to 54°W, having arrived in ten biogeographical regions ( Fig.…”

Phylogeographic and Bioclimatic Determinants of the Dorsal Pattern Polymorphism in the Italian Wall Lizard, Podarcis siculus

“…Studies on the geographic phenotypic variation of populations are less common. In fact, these studies, despite their great potential, are applicable only to abundant species whose phenotypic characteristics under study are easily decipherable from photos (e.g., [18][19][20]). Only a small number of studies have dealt with vertebrates, but also in this case, it is possible to have results on the frequencies of the different phenotypes with unprecedent geographical details [21].…”

Using iNaturalist to monitor adherence to best practises in bat handling

“…For example, photographs such as those on iNaturalist have been used to study the phenology of plants (Barve et al 2020) and emergence of insects (Jain and Tea 2020). Data on biotic interactions can be extracted from photos (Seltmann et al 2020, Gazdic and Groom 2019, Naude et al 2019, and they can also be used to determine physical traits of organisms (Drury et al 2019). Indeed, it is said that "A picture th is worth a thousand words" and in truth, the photographs on iNaturalist encapsulate much more information than is textualized in the associated metadata.…”