Spatio-temporal ecological niche modelling of multigenerational insect migrations

Abstract

Modelling ecological niches of migratory animals requires incorporating a temporal dimension, in addition to space. Here, we introduce an approach to model multigenerational migratory insects using time-partitioned environmental variables (by months and years) and time- and behaviour-partitioned records (breeding records to model reproductive habitat). We apply this methodology to modelling the Palearctic-African migratory cycle of the Painted Lady butterfly ( Vanessa cardui ), based on data encompassing 36 years (646 breeding sites from 30 countries). Each breeding record is linked to a particular time (month and year), and the associated values of the bioclimatic variables are used for an ensemble modelling strategy, to finally obtain monthly projections. The results show obligated movements, mostly latitudinal, for the species' successive generations across the overall range, and only scattered locations show high probabilities of reproduction year-round. The southernmost reproductive areas estimated for the Palearctic-African migratory pool reach equatorial latitudes from December to February. We thus propose a potential distribution for the winter ‘missing generations' that would expand the V. cardui migration cycle to encompass about 15 000 km in latitude, from northernmost Europe to equatorial Africa. In summer, Europe represents the major temporary resource for V. cardui , while January and February show the lowest overall suitability values, and they are potentially the most vulnerable period for the species to suffer yearly bottlenecks. In summary, we demonstrate the potential of the proposed niche modelling strategy to investigate migratory movements of insects.

Strong impacts of smoke polluted air demonstrated on the flight behaviour of the painted lady butterfly (Vanessa cardui L.)

“…V. cardui generally maintains a large population through multi successive generations every year (Stefanescu et al ., 2013; Talavera & Vila, 2017). V. cardui have excellent flight capacities, reflected in their annual mass migration between Africa and Europe (Talavera et al ., 2018; Menchetti et al ., 2019; Suchan et al ., 2019). Normally, they migrate from Europe to the Afrotropics in autumn and also evidence proved that they had a reverse northwards trans‐Saharan migration in Spring (Talavera & Vila, 2017; Talavera et al ., 2018).…”

Timing of mating, reproductive status and resource availability in relation to migration in the painted lady butterfly,Vanessa cardui

“…Painted ladies remain in this region in low numbers throughout the winter until the spring generation emerges and emigrates to Europe. As such, the species is largely absent in the summer, when temperatures are too high (Menchetti et al, 2019).…”

“…In this paper we examine more closely the relationship between reproduction and migration by focusing on the painted lady butterfly as a model migratory insect (Stefanescu et al, 2013). In the western Palaearctic this virtually cosmopolitan butterfly migrates from tropical Africa to Scandinavia and back again, in a succession of six or more annual generations, the longest known, regularly undertaken, multi-generational insect migration circuit (Stefanescu et al, 2013(Stefanescu et al, , 2016Menchetti et al, 2019). However, although recent ecological research on the migration of this butterfly has tackled various behavioural aspects such as orientation and flight strategies (Stefanescu et al, 2007(Stefanescu et al, , 2013Nesbit et al, 2009), no study has yet considered how migration and reproduction relate to each other.…”

Observer‐oriented approach improves species distribution models from citizen science data

“…Opportunistic citizen data have been shown to provide researchers with well‐approximated distribution ranges (or with further data on existing occurrences) and predictions of habitat use, necessary to address functional conservation efforts (e.g., Bruce et al., 2014; Tye et al., 2016). Moreover, citizen science data on online platforms has allowed researchers to perform studies on biogeography, alien species range expansion, species natural history, and interspecific interactions (Chandler et al., 2017; Menchetti et al., 2019; Mori et al., 2018; Mori & Menchetti, 2014; Sullivan et al., 2014; Vendetti et al., 2018). Therefore, citizen science is playing an important role in improving conservation biology, including also natural resource management and environmental preservation (Devictor et al., 2010; McKinley et al., 2017; Van der Wal et al., 2015).…”