Migration in butterflies: a global overview

Abstract

Insect populations including butterflies are declining worldwide, and they are becoming an urgent conservation priority in many regions. Understanding which butterfly species migrate is critical to planning for their conservation, because management actions for migrants need to be coordinated across time and space. Yet, while migration appears to be widespread among butterflies, its prevalence, as well as its taxonomic and geographic distribution are poorly understood. The study of insect migration is hampered by their small size and the difficulty of tracking individuals over long distances. Here we review the literature on migration in butterflies, one of the best‐known insect groups. We find that nearly 600 butterfly species show evidence of migratory movements. Indeed, the rate of ‘discovery’ of migratory movements in butterflies suggests that many more species might in fact be migratory. Butterfly migration occurs across all families, in tropical as well as temperate taxa; Nymphalidae has more migratory species than any other family (275 species), and Pieridae has the highest proportion of migrants (13%; 133 species). Some 13 lines of evidence have been used to ascribe migration status in the literature, but only a single line of evidence is available for 92% of the migratory species identified, with four or more lines of evidence available for only 10 species – all from the Pieridae and Nymphalidae. Migratory butterflies occur worldwide, although the geographic distribution of migration in butterflies is poorly resolved, with most data so far coming from Europe, USA, and Australia. Migration is much more widespread in butterflies than previously realised – extending far beyond the well‐known examples of the monarch Danaus plexippus and the painted lady Vanessa cardui – and actions to conserve butterflies and insects in general must account for the spatial dependencies introduced by migratory movements.

Seasonal spatial dynamics of butterfly migration

“…It depends on some temporary inhibition of station ‐ keeping responses but promotes their eventual disinhibition and recurrence’ . This definition was extended and clarified by Dingle (2014) and was used in a recent global review of butterfly migration (Chowdhury et al, 2021c). From a vertebrate‐centric viewpoint, many butterfly migrations might be interpreted as ‘dispersal’ (Chowdhury et al, 2021c).…”

“…We downloaded occurrence records (14,089,283 records; downloaded 11th May 2020) without specifying year or life stage for all 568 migratory butterfly species, listed by Chowdhury et al, 2021c, from the Global Biodiversity Information Facility (https://www.gbif.org/; GBIF.org, 2020; Figure ). GBIF is an international network of data infrastructure that compiles information from a range of sources including museum specimens and citizen science records.…”

“…Butterfly migration is a widespread phenomenon that has long fascinated observers of nature. Globally, at least 568 of 18,000 butterfly species are known to migrate, with some showing short‐distance migration, and others performing transcontinental journeys (Chowdhury et al, 2021c). Populations of migratory species can be impacted by environmental conditions anywhere along their migratory routes, which often span international borders.…”

“…While undertaking migratory journeys, butterflies often stop to refuel by nectaring on food plants in suitable areas, and habitat loss and fragmentation mean that opportunities for such stopovers may be diminishing (Flockhart et al, 2015; Wilson et al, 2015). However, literature on migratory butterfly conservation is mostly based on the monarch Danaus plexippus , and little is known about the seasonal distributions, let alone the population trends and conservation status of hundreds of other migratory butterflies (Chowdhury et al, 2021c; Oberhauser & Peterson, 2003; Zalucki et al, 2016). Whereas North American monarchs have declined steeply, other migratory species in Europe, such as European painted lady Vanessa cardui , red admiral V .…”

Bowel Movement: Integrating Host Mobility and Microbial Transmission Across Host Taxa

“…With insects, the influence of migration is less clear. Though, insect migration is often associated with the spectacular mass migration events of the monarch butterfly ( Danaus plexippus ) or the painted lady ( Vanessa cardui ), migration abilities are not uncommon for other butterflies or nocturnal moth, but remain often unnoticed as they fly in lower numbers or at night ( Chowdhury et al, 2021 ). But even seasonal mass migration events are easily overlooked, when insects are small and fly at high altitudes like the marmalade hoverfly ( Episyrphus balteatus ) ( Hu et al, 2016 ; Wotton et al, 2019 ; Satterfield et al, 2020 ).…”