Estimation of bumblebee queen dispersal distances using sibship reconstruction method

Area of Science:

• Ecology
• Evolutionary Biology
• Conservation Biology

Background:

• Dispersal ability is critical for species survival amidst habitat fragmentation and climate change.
• Bumblebees are vital pollinators facing increasing environmental pressures.
• Understanding bumblebee dispersal is essential for effective conservation strategies.

Purpose of the Study:

• To quantify the dispersal distances of queens in two common bumblebee species (Bombus pascuorum and B. lapidarius) in an arable landscape.
• To compare queen dispersal with worker foraging distances to refine dispersal estimates.
• To assess the implications of observed dispersal distances for gene flow and population cohesion.

Main Methods:

• DNA sampling from workers (spring/summer) and queens (following spring) across 14 landscape sites.
• Utilizing sibship reconstruction methods, with the program Colony identified as most accurate.
• Comparing queen dispersal data with worker foraging ranges to correct for potential false sister pair identifications.

Main Results:

• Bombus pascuorum queens disperse at least 3 km, and B. lapidarius queens disperse at least 5 km.
• These dispersal distances suggest sufficient gene flow for maintaining genetic cohesion in common bumblebee species.
• Rare bumblebee species may struggle to disperse effectively beyond 10 km.

Conclusions:

• Queen dispersal in common bumblebee species facilitates gene flow over several kilometers, crucial for genetic cohesion.
• Observed dispersal capabilities have significant implications for the conservation of fragmented bumblebee populations.
• Conservation efforts should consider species-specific dispersal abilities, especially for rare bumblebees.