Lack of inbreeding avoidance during mate selection in migratory monarch butterflies

• Type of Material: Article
• Authors: Scott M Villa, Emory University; Kieran P Kelly, Emory University; Miles G Hollimon, Davidson College; Karl J Protil, lll, Emory University; Jacobus C de Roode, Emory University
• Language: English
• Date: 2022-05-01
• Publisher: Elsevier B.V
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2024 Elsevier B.V., its licensors, and contributors.
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1016/j.beproc.2022.104630
• Title of Journal or Parent Work: Behavioural Processes
• Volume: 198
• Start Page: 104630
• End Page: 104630
• Grant/Funding Information: This work was supported by both a National Institutes of Health K12 grant (GM00680), National Science Foundation grant (IOS-1922720) to JdR, and the SURE program at Emory.
• Keywords: Butterflies; Lepidoptera; Inbreeding; Mate choice; Body size; Male; Animals; Reproduction; Humans; Marriage; Female; Coercive mating
• Research Categories: Biology, General; Biology, Zoology

Abstract

Inbreeding is generally thought to have negative consequences for organismal health. However, despite the potential fitness effects, it remains surprisingly common among wild populations. In many cases, the complex factors that underlie mating dynamics make predicting whether individuals should or do avoid inbreeding quite challenging. One reason inbreeding may persist among species is that the likelihood of encountering relatives can be rare. Thus, even if inbreeding has severe consequences, selection to avoid mating with kin will be weak in species that are highly dispersed. Here we investigated if migratory monarch butterflies (Danaus plexippus), which are famous for their dispersal ability, actively avoid inbreeding. We found that neither female nor male monarchs choose mates based on relatedness. These results support the hypothesis that movement ecology can mask the deleterious effects of inbreeding and relax selection for active inbreeding avoidance behaviors. Overall, our data add to the growing list of studies showing that inbreeding avoidance is not the behavioral “default” for most species. We also highlight the implications that inbreeding may have on the declining populations of this iconic butterfly.