Identification “by eye”: integrative character assessment informs regional field identification of greater fritillary butterflies (Nymphalidae: Speyeria)
The pronounced morphological variability exhibited by Speyeria butterflies can hinder the identification of these taxa, and thus presents a challenge to their management and conservation. While several studies have documented declines in American populations of Speyeria due to habitat change, the response of Canadian populations of Speyeria to widespread anthropogenic pressures remains poorly understood due to their difficult identification. Here, we assessed the utility of morphological characters recommended in regional field guides for the identification of Speyeria butterflies in Canada, focusing on three morphologically variable subspecies that inhabit boreal forests subject to widespread oil sands extraction: S. aphrodite manitoba, S. atlantis hollandi, and S. hesperis beani. We scored 159 specimens for 11 morphological characters, and complimented this data by sequencing the barcode region of the COI gene for 15 of these specimens. Our results indicate a high level of intraspecific variability in several characters, and the COI gene revealed that initial morphological identifications were incorrect. A further assessment of character reliability identified sets of morphological characters that, in combination with specimen sex and species natural history, improved subspecies identification. Notably, we found that a relatively novel field marker—in vivo eye color—consistently distinguished S. aphrodite manitoba from S. hesperis beani and S. atlantis hollandi. Our results emphasize the importance of using an integrative approach for the accurate identification of morphologically variable species, particularly in situations where molecular methods are not readily available, such as citizen science programs.
KeywordsCOI gene Speyeria Morphology Species identification Citizen science
We thank eButterfly and all of their affiliated citizen scientists for collecting, reporting, and vetting butterfly observation data used in this publication. We additionally thank F. and T. Sperling, B. Acorn, and S. Ferguson for specimen collection, and the Molecular Biology Services Unit at the University of Alberta for sequencing support. Funding for the research was provided by two Alberta Conservation Association Grant in Biodiversity to EC and FR, an NSERC Discovery Grant to Felix Sperling, and a DeWind Award from the Xerces Society to FR.
FR and EOC contributed equally as first authors to the manuscript; All authors designed the study and contributed to draft revisions; FR and FC collected Speyeria butterflies in the Alberta boreal forest; FC scored all specimens and prepared the data for analysis; FR and EOC conducted the analyses and prepared the R script.
Compliance with ethical standards
Conflicts of interest
The authors have no conflicts of interest to declare.
This research did not involve human participants, and thus an informed consent form was not necessary. The study complies with the University of Alberta Animal Ethics Policy.
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