Biology subjects

Batsleer, F.

Publications and source records attributed to Batsleer, F..

5 recordsLinked to original sources

bioRxiv2023

Unravelling arthropod movement in natural landscapes: small-scale effects of body size and weather conditions

O_LIArthropod movement has been noticeably understudied compared to vertebrates. A crucial knowledge gap pertains to the factors influencing arthropod movement at habitat boundaries, which has direct implications for population dynamics and gene flow. While larger arthropod species generally achieve greater dispersal distances and large-scale movements are affected by weather conditions, the applicability of these relationships at a local scale remains uncertain. Existing studies on this subject are not only scarce but often limited to a few species or laboratory conditions. C_LIO_LITo address this knowledge gap, we conducted a field study in two nature reserves in Belgium, focusing on both flying and cursorial (non-flying) arthropods. Over 200 different arthropod species were captured and released within a circular setup placed in a resource-poor environment, allowing quantification of movement speed and direction. By analysing the relationship between these movement variables and morphological (body size) as well as environmental factors (temperature and wind), we aimed to gain insights into the mechanisms driving arthropod movement at natural habitat boundaries. C_LIO_LIFor flying species, movement speed was positively correlated with both body size and tailwind speed. In contrast, movement speed of cursorial individuals was solely positively related with temperature. Notably, movement direction was biased towards the vegetated areas where the arthropods were originally caught, suggesting an internal drive to move towards suitable habitat. This tendency was particularly strong in larger flying individuals and under tailwind conditions. Furthermore, both flying and cursorial taxa were hindered from moving towards the habitat by strong upwind. C_LIO_LIIn conclusion, movement speed and direction at patch boundaries are dependent on body size and prevailing weather conditions, and reflect an active decision-making process. C_LI

ecology↗

bioRxiv2023

Strong gene flow across an urbanized coastal landscape in a dune specialist digger wasp

ContextGenetic connectivity is often disrupted by anthropogenic habitat fragmentation, and therefore often a focus in landscape-scale conservation. Landscape genetics methods allow for studying functional connectivity in heterogenous landscapes in detail and have the potential to inform conservation measures for a species regional persistence. Yet, for insects, functional connectivity through landscape genetics remains largely unexplored. ObjectivesWe aimed to assess the functional connectivity in the dune-specialist digger wasp Bembix rostrata, in a human-altered 15 km section along the Belgian coast, based on landscape genetics methods. MethodsWe optimised landscape resistance distances according to individual genetic distances with the package ResistanceGA. We combined this with a multi-model inference approach to deduce relative conductance or resistance of gene flow to natural and anthropogenic landscape types. ResultsOverall, the populations of this dune-specialist insect are genetically well-connected. We detected-- on top of the prominent background process of isolation-by-distance--a weak but consistent signal of urban features facilitating gene flow. ConclusionsUrban areas are not a barrier to genetic connectivity of the dune-specialist insect B. rostrata in the focal human-altered landscape. However, because urbanisation leads to larger scale fragmentation, its impact on the distribution of populations in the landscape and related effective regional gene flow remains substantial. As this species depends on early-succession dune vegetations, restoring and increasing sand dynamics at the local and landscape scale should be the focus of conservation aimed at the regional species persistence, rather than trying to increase habitat connectivity in this human-altered dune ecosystem.

ecology↗

bioRxiv2022

Asymmetrical gene flow between coastal and inland dunes in a threatened digger wasp

1.Connectivity is a species- and landscape-specific measure that is key to species conservation in fragmented landscapes. However, information on connectivity is often lacking, especially for insects which are known to be severely declining. Patterns of gene flow constitute an indirect measure of functional landscape connectivity. We studied the population genetic structure of the rare digger wasp Bembix rostrata in coastal and inland regions in and near Belgium. The species is restricted to sandy pioneer vegetations for nesting and is well known for its philopatry as it does not easily colonize vacant habitat. It has markedly declined in the last century, especially in the inland region where open sand habitat has decreased in area and became highly fragmented. To assess within and between region connectivity, we used mating system independent population genetic methods suitable for haplodiploid species. We found more pronounced genetic structure in the small and isolated inland populations as compared to the well-connected coastal region. We also found a pattern of asymmetrical gene flow from coast to inland, including a few rare dispersal distances up to 200 to 300 km based on assignment tests. We point to demography, wind and difference in dispersal capacities as possible underlying factors that can explain the discrepancy in connectivity and asymmetrical gene flow between the different regions. Despite B. rostrata being a poor colonizer, gene flow between existing populations appeared not highly restricted, especially at the coast. Therefore, to improve the conservation status of B. rostrata, the primary focus should be to preserve and create sufficient habitat for this species to increase the number and quality of (meta)populations, rather than focusing on landscape connectivity itself.

ecology↗

bioRxiv2021

Honest cues contribute to male choice for female guarding in a herbivorous spider mite.

Mate choice is a wide-spread phenomenon with important effects on ecological and evolutionary dynamics of successive generations. Increasing evidence shows that males can choose females if females vary in quality and these mating choices can strongly impact fitness. In the herbivorous spider mite Tetranychus urticae males engage in precopulatory mate guarding of quiescent females, and it is known that females vary in their time to sexual maturity and fecundity. However, our understanding of how males maximize their reproductive success and which female phenotypic traits are important cues for their mating decisions are still limited. In many arthropod species, female body size and pheromones are well known proxies for fecundity. These traits--and thus possibly male mating decisions--are however sensitive to environmental (dietary) stress. By allowing males to freely choose amongst many (synchronized) females in a controlled semi natural environment, we found that guarded females have a higher fecundity and are closer to sexual maturity than non-guarded females. Despite the fact that female body size was positively correlated with fecundity and significantly influenced by the environment, males did not discriminate on body size nor did we find evidence that they used other cues like cuticular pheromones or copying behavior (social cues). In conclusion we were able to show male mate preference for females that are closer to sexual maturity and have higher fecundity, but we were unable to identify the female traits that signal this information

animal behavior and cognition↗

bioRxiv2021

Biomorphogenic feedbacks and the spatial organisation of a dominant grass steer dune development

Nature-based solutions to mitigate the impact of future climate change depend on restoring biological diversity and natural processes. Coastal foredunes represent the most important natural flood barriers along coastlines worldwide, but their area has been squeezed dramatically because of a continuing urbanisation of coastlines, especially in Europe. Dune development is steered by the development of vegetation in interaction with sand fluxes from the beach. Marram grass (Calamagrostis arenaria, formerly Ammophila arenaria) is the main dune building species along most European coasts, but also in other continents where the species was introduced. Engineering of coastal dunes, for instance by building dunes in front of dikes, needs to be based on a solid understanding of the species interactions with the environment. Only quantitative approaches enable the further development of mechanistic models and coastal management strategies that encapsulate these biomorphogenic interactions. We here provide a quantitative review of the main biotic and physical interactions that affect marram grass performance, their interactions with sand fluxes and how they eventually shape dune development. Our review highlights that the species spatial organisation is central to dune development. We further demonstrate this importance by means of remote sensing and a mechanistic model and provide an outlook for further research on the use of coastal dunes as a nature-based solution for coastal protection.

ecology↗