Abstract
• The current distribution of F. rufa populations at the species’ northern limit was established through systematic surveys of three key sites. The results show populations are largely concentrated within Gait Barrows and Arnside Knott, whilst nearly absent from Eaves Wood.
• The influence of canopy cover on nest distribution was found to be significant overall with increased canopy cover linked to nest decline and abandonment. However, within-site analysis revealed contrasting relationships between canopy openness and nest status across populations, which have been attributed to differences in site characteristics.
• An overall relationship between reduced canopy openness and active nest mound size was identified but within-site analysis revealed this relationship to be weak. The results are considered to support previous findings that the species shows a distinct preference for woodland edge habitat.
• Changes to the northern distribution were analysed via survey records and reports. This revealed a marked decline in active nests within all populations in the decade prior to the study. Gait Barrows and Arnside Knott populations have since shown signs of a partial recovery but still appear to be weakened and contracted; whilst the Eaves Wood population appears close to extinction.

[uploaded with the permission of the author]

#aculeates

Published 16th September 2019