Biology subjects

Baguette, M.

Publications and source records attributed to Baguette, M..

8 recordsLinked to original sources

bioRxiv2026

Switching to one or the other : Shorebirds behavioural flexibility in food transport mechanisms

Shorebirds provide an excellent model for investigating the relationship between bill morphology and food acquisition. Food acquisition comprises three successive behavioural stages: foraging (locomotion and prey capture), feeding (food handling and transport), and swallowing. During food transport, these birds use two non-lingual mechanisms, surface-tension transport (ST) and ballistic transport (BT), whose characteristics depends on the kinematics of head and beak movements and the physical properties of the food. We investigated the behavioural flexibility of these transport mechanisms in captive and free-ranging individuals of two species with contrasting beak morphologies: the Pied avocet (Recurvirostra avosetta) and the Black-winged stilt (Himantopus himantopus). Although these species have beaks of a similar size, avocets are distinguished by their upward-curved beaks, whereas stilts have a rather straight beak. We examined the effects of food water content and the presence or absence of water in the beak on food transport by quantifying maximum gape, maximum head displacement, and maximum head velocity. Transport kinematics were jointly influenced by food properties and water availability in the beak. Moist food improved transport performance in both species, whereas dry food required compensatory increases in gape amplitude and head movements, demonstrating that neither ST nor BT constitutes a fixed behavioural sequence. Species also differed consistently in their transport strategies: Black-winged stilts relied on slower, larger-amplitude head movements, whereas Pied Avocets exhibited faster, more precise movements, particularly when water was present. These findings demonstrate that ST and BT share common biomechanical foundations while being governed by rapid kinematic adjustments to changing environmental conditions that probably correspond to flexible motor control. This behavioural flexibility in food transport is therefore likely to enhance feeding performance and ecological resilience in the heterogeneous habitats occupied by shorebirds, suggesting that context-dependent modulation of transport behaviour represents an important adaptive feature of these shorebirds.

animal behavior and cognition↗

bioRxiv2025

Character displacement in shorebirds

Modification of phenotypic traits induced by character displacements allow species to coexist by reducing interspecific competition. This study explores if and how shorebirds partition feeding ressources by foraging at different water depths outside the breeding season. During this period, communities of up to dozen shorebird species coexist on suitable habitats at land-water interfaces. By video recording 22 species of migrating and wintering shorebirds in different sites, we show that their distribution according to the water height at which they forage is not random but follows a gradient of increasing water height according to increasing species body size. Species-specific beak and tarsus lengths are positively correlated with the water height at which the different species forage. Our data do not support a trade-off in investment between beak length and tarsus length in our study species set. Congeneric species that are expected to be morphologically and ecologically more similar forage at contrasted water heights. Altogether, our findings supports the idea of resource partitioning, and consequently of competition relaxation, by morphological and/or by behavioral character displacements.

evolutionary biology↗

bioRxiv2025

Beak elongation as key innovation in shorebird adaptive radiation

Adaptive radiations are often associated with phenotypic innovations that broaden ecological opportunity and bias subsequent ecological divergence. In shorebirds (Charadriiformes), variation in beak length has long been linked to resource partitioning, yet its role as a functional innovation has remained largely untested. Here, we integrate behavioural, morphological, and phylogenetic data from 29 Western Palearctic shorebird species to evaluate whether beak elongation fulfils key expectations of a candidate innovation by being repeatedly associated with ecological and functional transitions. Species with longer than expected beaks relative to body size consistently exhibit distinct locomotor, prey-capture, and food-transport strategies. These integrated morphological-behavioural syndromes recur across independent lineages, suggesting convergent evolution driven by shared ecological constraints. Phylogenetic analyses indicate multiple independent origins of relative beak elongation, supporting its role as a repeated evolutionary solution. Together, our results support a functionally integrated view of adaptation, in which coordinated changes in morphology, sensory investment, and behaviour facilitate access to alternative foraging microhabitats and enable repeated ecological transitions within shorebirds. More broadly, this study provides a testable framework for identifying candidate innovations based on replicated trait-niche associations. O_FIG O_LINKSMALLFIG WIDTH=198 HEIGHT=200 SRC="FIGDIR/small/671984v2_ufig1.gif" ALT="Figure 1"> View larger version (54K): org.highwire.dtl.DTLVardef@185f912org.highwire.dtl.DTLVardef@a33baforg.highwire.dtl.DTLVardef@a37b35org.highwire.dtl.DTLVardef@ee0831_HPS_FORMAT_FIGEXP M_FIG C_FIG

evolutionary biology↗

bioRxiv2024

Floral phenotypic divergence and genomic insights in an Ophrys orchid: Unraveling early speciation processes

SummaryO_LIAdaptive radiation in Ophrys orchids leads to complex floral phenotypes that vary in scent, color and shape. C_LIO_LIUsing a novel pipeline to quantify these phenotypes, we investigated trait divergence at early stages of speciation in six populations of Ophrys aveyronensis experiencing recent allopatry. By integrating different genetic/genomic techniques, we investigated: (i) variation and integration of floral components (scent, color and shape), (ii) phenotypes and genomic regions under divergent selection, and (iii) the genomic bases of trait variation. C_LIO_LIWe identified a large genomic island of divergence, associated with phenotypic variation in particular in floral odor. We detected potential divergent selection on macular color, while convergent selection was suspected on floral morphology and for several volatile olfactive compounds. We also identify candidate genes involved in anthocyanin and in steroid biosynthesis pathways associated with standing genetic variation in color and odor. C_LIO_LIThis study sheds light on early differentiation in Ophrys, revealing patterns that often become invisible over time, i.e., the geographic mosaic of traits under selection and the early appearance of strong genomic divergence. It also supports a crucial genomic region for future investigation and highlights the value of a multifaceted approach in unraveling speciation within taxa with large genomes. C_LI

evolutionary biology↗

bioRxiv2023

Climate change promoted allopatric divergence and explains the current disjunct geographic distribution of the Ophrys aveyronensis species complex (Orchidaceae)

AimSpecies with disjunct geographic distributions provide natural opportunities to investigate incipient or recent allopatric divergence. The combination of both genetic and ecological data may be fruitful to decipher the causes of such pattern: i) actual vicariance, ii) successful colonization from one source range to a new range (dispersal, biological introduction) or iii) parallel convergent evolution. LocationSouthern France and Northern Spain. TaxonThe bee orchid Ophrys aveyronensis (and its two recognized subspecies O. a. subsp. aveyronensis and O. a. subsp. vitorica) displays a disjunct geographic distribution with two subranges separated by 600 km on both sides of the Pyrenees Mountains. MethodsThrough a combination of population genomics and Ecological Niche Modelling (ENM), we investigated the causes of this intriguing biogeographic pattern. ResultsThe population genomic data demonstrate that all the studied populations exhibit similar patterns of genetic diversity and dramatic decrease in effective size compared to the ancestral population. Significant genetic differentiation and reciprocal monophyly exist between populations of the two subranges of O. aveyronensis, despite a very recent divergence time as young as ca. 1500 generations ago. Moreover, (paleo-)ecological Niche Modelling analyses support that the disjunct geographic distribution of the O. aveyronensis is consistent with a range split of a broad ancestral range, contraction and distinct longitudinal and latitudinal shifts in response to climate warming during the Holocene. Main ConclusionThe congruence of the results obtained from both population genomics and ENM approaches documents how very recent continental allopatric divergence initiated speciation in this system. Ophrys aveyronensis provides a promising opportunity to study the onset of reproductive isolation and parallel evolution following an initial stage of geographic separation in a group with high diversification rate.

evolutionary biology↗

bioRxiv2020

MetaConnect, a new platform for population viability modelling to assist decision makers in conservation and urban planning

In a context of global change, scientists and policy-makers require tools to address the issue of biodiversity loss. Population viability analysis (PVA) has been the main tool to deal with this problem. However, the tools developed during the 90s poorly integrate recent scientific advances in landscape genetics and dispersal. We developed a flexible and modular modelling platform for PVA that addresses many of the limitations of existing software. MetaConnect is an individual-based, process-based and PVA-oriented modelling platform which could be used as a research or a decision-making tool. Here, we present the core base modelling of MetaConnect. We demonstrate its potential use through a case study illustrating the platforms capability for performing integrated PVA including extinction probability estimation, genetic differentiation and landscape connectivity analysis. We used MetaConnect to assess the impact of infrastructure works on the natterjack toad metapopulation functioning.

ecology↗

bioRxiv2019

Patterns of gene flow across multiple anthropogenic infrastructures: insights from a multi-species approach

1.Large-scale Transportation Infrastructures (LTIs) are among the main determinants of landscape fragmentation, with strong impacts on animal dispersal movements and metapopulation functioning. Although the detection of LTIs impacts is now facilitated by landscape genetic tools, studies are often conducted on a single species, although different species might react differently to the same obstacle. Multi-specific approaches are thus required to get a better overview of the impacts of human-induced fragmentation. We surveyed four species (a snake, an amphibian, a butterfly and a ground-beetle) in a landscape fragmented by six LTIs: a motorway, a railway, a country road, a gas pipeline, a power line and a secondary road network. We showed that half of the overall explained genetic variability across all species was due to LTIs. While the butterfly was seemingly not impacted by any LTI, the genetic structure of the three other species was mostly influenced by roads, motorway and railway. The power line did not affect any species and the gas pipeline only impacted gene flow in the ground-beetle through forest fragmentation, but other LTIs systematically affected at least two species. LTIs mostly acted as barriers but we showed that some LTIs could somehow promote gene flow, embankments probably providing favourable habitats for vertebrate species. Considering the high variability in species response to LTIs, we argue that drawing general conclusions on landscape connectivity from the study of a single species may lead to counterproductive mitigation measures and that multi-species approaches should be more systematically considered in conservation planning.

ecology↗

bioRxiv2017

Habitat Fragmentation Causes Coevolutionary Burning Spots

Habitat fragmentation increasingly threatens the services provided by natural communities and ecosystem worldwide. An understanding of the underlying eco-evolutionary processes in natural settings is lacking, yet critical to realistic and sustainable conservation. Through integrating the multivariate genetic, biotic and abiotic facets of a natural community network experiencing various degrees of habitat fragmentation, we provide unique insights into the processes underlying community functioning in real, natural conditions. The focal community network comprises a parasitic butterfly of conservation concern, and its two obligatory host species, a plant and an ant. We show that fragmentation of butterfly habitat has the potential to impair the balance between dispersal and coevolution. This process can cause coevolutionary burning spots of decreased genetic diversity and therefore of increased extinction risk. We stress that ignoring such eco-evolutionary feed-backs inherent to the very functioning of natural communities can strongly impact their persistence.\n\nOne Sentence SummaryCommunities under threat of habitat fragmentation suffer increased extinction risk through coevolutionary overheating.

evolutionary biology↗