Small local population sizes and high habitat patch fidelity in a specialised solitary bee.
propensity, and local population sizes is essential for successful conservation of A. hattorfiana. The investigated local bee populations (n = 78) were dominated by small local populations and 60% were smaller than 10 female individuals and 80% were smaller than 50 female individuals. The area of the median occupied habitat patch was 1.25 hectare and harboured 7 female bees. Mark-releaserecapture studies of female A. hattorfiana revealed a sedentary behaviour. Among pollen-foraging female bees the
average registered distance moved was 46 m. The patch emigration rate was about 2%, with an observed maximum colonization distance of 900 m. Only 10% of the individuals crossed areas without the pollen plant within grassland
patches, such as unpaved roads, stone walls and small treestands, even if these areas were less than 10 m wide. This study shows that solitary bees can occur in local populations of extremely small size and they have a sedentary behaviour. These are features that usually increase the risk
of local population extinction.
- Andrena hattorfiana
- Knautia arvensis
- ISSN: 1366-638X