Biology subjects

Bataille, C. P.

Publications and source records attributed to Bataille, C. P..

3 recordsLinked to original sources

bioRxiv2025

Niche partitioning and limited mobility characterise Middle Pleistocene kangaroos from eastern Australia

Australias Quaternary fossil record is characterised by a high diversity of macropodid taxa. Based on fossil faunal assemblages, it has been hypothesised many macropodids lived in sympatry during the Pleistocene, however, local geographic and dietary overlap is equivocal due to taphonomic uncertainty. Modern macropodid species rarely exhibit sympatry, suggesting anthropogenic or environmental changes may have disrupted these communities. Using Sr and C isotopes, we reconstruct foraging ranges and dietary preferences of several fossil macropodid lineages recovered in Middle Pleistocene cave deposits, at Mount Etna Caves, central eastern Queensland, Australia. Our results show that most macropodids, baring a single Petrogale potentially dispersing > 60 km, had limited foraging ranges and remained within 15 km of the fossil site. Moderate to large scale dispersal in individual Petrogale mirrors male-biased dispersal observed in some modern Petrogale populations indicating some individuals have the propensity to move between isolated colonies when corridors for dispersal are present. Smaller macropodids show dietary preferences similar to modern counterparts, while Protemnodon exhibit a division between C3/C4 intake, potentially indicating species-level differences. The analysis of geographic range and diet of this fossil assemblage reveals that macropodids partitioned on the landscape around the cave with a C3-dominant community - comprised of Protemnodon, Petrogale, and Thylogale - to the northwest, and a C4-dominant grassland community - comprised of Notamacropus and isolated members of Protemnodon and Petrogale - to the south. Therefore, we conclude, that although faunal assemblages alone suggest a larger number of macropodids living in sympatry, isotopic proxies uncover complex habitat partitioning between C3 and C4 environments around Mount Etna Caves.

paleontology↗

bioRxiv2023

Intercontinental panmixia despite distinct migration distances in the trans-Saharan butterfly migrant Vanessa cardui

The painted lady butterfly Vanessa cardui is renowned for its virtually cosmopolitan distribution and the remarkable long-distance migrations that are part of its annual, multi-generational migratory cycle. Recently, V. cardui individuals were found north and south of the Sahara in the autumn, suggesting distinct migratory behaviours within the species. However, the evolutionary and ecological factors shaping these differences in migratory behaviour remain largely unexplored. Here, we performed whole-genome resequencing and analysed the hydrogen and strontium isotopes of 40 V. cardui individuals simultaneously collected in the autumn from regions both north and south of the Sahara. Our investigation revealed two main migratory groups: (i) short-distance migrants, journeying from temperate Europe to the circum-Mediterranean region and (ii) long-distance migrants, originating from Europe, crossing the Mediterranean Sea and Sahara, and reaching West Africa, covering up to over 4,000 km. Despite these stark differences in migration distance, a genome-wide analysis revealed that both short- and long-distance migrants belong to a single intercontinental panmictic population extending from northern Europe to sub-Saharan Africa. Contrary to common biogeographic patterns, the Sahara is not a catalyst for population structuring in this species. No significant genetic differentiation or signs of adaptation and selection were observed between the two migratory phenotypes (pairwise FST = 0.001 {+/-} 0.006). Nonetheless, two individuals, which were early arrivals to West Africa and covered longer migration distances, exhibited some genetic differentiation. The lack of genetic structure between short- and long-distance migrants suggests that migration distance in V. cardui is a plastic response to environmental conditions. Significance statementAlthough migratory insects dominate living biomass fluxes and impact agriculture, ecosystems, and human communities, little is known about the controls of their migratory behavior. Our study develops an interdisciplinary framework, applied to the migratory butterfly V.cardui, to explore the genetic basis of variation in insect migration behavior. We leverage new generation isotope geolocation techniques to uncover striking differences in butterfly behaviour, with some individuals migrating short distances within the circum-Mediterranean region and others migrating thousands of kilometers across the Mediterranean Sea and Sahara. This major difference does not coincide with genetic differentiation or population structure and is likely a plastic response to environmental cues. This study provides a ground-breaking framework to study migration in insects.

evolutionary biology↗

bioRxiv2022

Metals and metal isotopes in insect wings: Implications for diet, geolocation and pollution exposure

Anthropogenic activities are exposing insects to abnormal levels of toxic metals, with unknown implications for migratory insects. Simultaneously, metals and metal isotopes have become promising tools for the geolocation of migratory insects. Furthering our understanding of metal cycling in insect tissues is essential, both for the development of metals and metal isotopes as geolocation tools, and for assessing the toxicity risks of metals to insects. We conducted a diet-switching experiment on monarch butterflies (Danaus plexippus) with controlled larval and adult diets to evaluate the dietary and environmental sources of 23 metals and metalloids, strontium isotopes, and lead isotopes to insect wing tissues over a period of 8 weeks. Concentrations of Ca, Co, and Sb differed between the sexes. Ni and Zn bioaccumulated in the insect wing tissues over time, likely from the adult diet, while increases in Al, Cr, Cd, Cu, Fe, and Pb were likely from external sources (i.e., dust aerosols). Bioaccumulation of Pb in the monarch wings was confirmed by Pb isotopes to be from external anthropogenic sources, revealing the potential of Pb isotopes to become an indicator and tracer of metal pollution exposure along migratory paths. Concentrations of Ba, Cs, Mg, Na, Rb, Sr, Ti, Tl, and U appeared to be unaffected by dietary or environmental contamination and should be further developed for geolocation purposes. Strontium isotope ratios remained indicative of the larval diet, at least in males, supporting its potential as a geolocation tool. However, the difference in strontium isotope ratios between sexes, as well as the possibility of external contamination by wetting, requires further investigation. Our results demonstrate the complexity of metal cycling in insects and the need for further investigations, as well as the value of studying metals to develop new tools to quantify pollution exposure, metal toxicity and insect mobility.

ecology↗