Bee Hotels as a Tool for Post-Fire Recovery of Cavity-Nesting Native Bees

Area of Science:

• Ecology
• Conservation Biology
• Entomology

Background:

• Wildfires exacerbated by climate change threaten native pollinators, including wild bees.
• Post-fire environments may lack crucial nesting resources, such as pre-made holes, for cavity-nesting bees.
• Artificial nesting substrates (bee hotels) have not been previously utilized to aid bee recovery in fire-affected habitats.

Purpose of the Study:

• To assess the efficacy of bee hotels in supporting native bee populations in Australian bushland impacted by the 2019/2020 wildfires.
• To investigate the recovery of nesting resources and native bee colonization in post-fire environments with and without artificial nesting substrates.
• To examine the potential competitive interactions between native bees and honeybees in fire-affected habitats.

Main Methods:

• Installation and monitoring of 1000 artificial nesting substrates (bee hotels: 500 bamboo, 500 wooden) across five burnt sites.
• Comparison with three control sites lacking bee hotels.
• Visual surveys and nest occupancy assessments conducted by a native bee ecologist from September to March 2021/2022.

Main Results:

• Initial low uptake of bee hotels increased, with full occupancy by March.
• Over 800 native bee nests were successfully created in the installed bee hotels.
• Sites with bee hotels showed significantly higher native bee abundance compared to control sites.
• A negative association between honeybee density and native bee nest occupancy was observed, indicating potential competition.

Conclusions:

• Bee hotels, when appropriately designed, can effectively support and boost populations of cavity-nesting bees in post-fire landscapes.
• The use of artificial nesting resources is a viable strategy for enhancing native bee recovery after wildfires.
• Managing invasive honeybee populations may be important for maximizing the benefits of conservation interventions for native bees in fire-affected areas.