Brans Victor

To what extent do we need to understand the functional habitat and its dynamics for Population Viability Analysis models ?  Example with the butterfly Boloria eunomia in the Belgian Ardenne

Understanding a species' functional habitat—its essential resources (food, breeding sites, microclimate…) and their spatio-temporal dynamics—would improve the accuracy of viability predictions. However, this is rarely feasible for rare or endangered species, where such analyses are most needed. To guide efficient conservation and modeling, the priority is thus to identify (1) key resources to generally consider and (2) if their spatio-temporal dynamics need to be taken into account. The Bog Fritillary butterfly (Boloria eunomia), studied by UCLouvain since 1992 in Belgium’s Plateau des Tailles, serves as a model to tackle these challenges due to long-term abundance time series (via Capture-Mark-Recapture data) and its relatively well-known functional habitat. Its habitat (wet meadows and peatlands) faces threats like fragmentation, climate change, and pollution. Research has already explored its demography, dispersal, resource preferences (bistorts as the sole host plant, tussocks as larval thermoregulation structures, microclimatic conditions for larvae), and parasitism effects on spatial use. The two main goals of this doctoral research project are then to (1) identify additional critical resources to consider (e.g., host plant quality, weather and microclimate conditions at different life stages), and (2) assess how all these resources and their spatio-temporal dynamics—natural or influenced by beavers—impact the butterfly’s (meta)population dynamics and viability.

Supervisor : Nicolas Schtickzelle