Population assessment and foraging ecology of nest aggregations of the rare solitary bee, Eucera longicornis at Gatwick Airport, and implications for their management

Abstract

Eucera longicornis is a rare solitary bee that is in decline throughout its range in Britain and other European countries. Two nest aggregations that had been previously discovered in 2014 on land owned and managed by Gatwick Airport, Southern England, were studied in 2017, 2018 and 2019 to obtain information relevant to their conservation. Population estimates using mark recapture showed that the larger aggregation had a maximum population estimate of 659 individuals in 2018, with the smaller aggregation reaching a maximum population estimate of 221 in 2019. In terms of foraging requirements, microscopic analysis of pollen samples from females returning from their nests identified a total of 12 plant taxa across all years and both aggregations. Fabaceae pollen was present in 100% of samples and on average comprised 90% of each sample, indicating that the species is oligolectic. Both nest aggregations were on sloping banks of exposed soil arising from land management by the airport in 1999. Floral surveys of the landscape indicate that within 100 m of both aggregations Fabaceae species are the most abundant due to the presence of a legume rich wildflower meadow alongside the adjacent river Mole, which was sown by Gatwick Airport. Eucera longicornis at Gatwick Airport are an example of how if managed appropriately, industrial areas can provide valuable refuges for rare wildlife. Although there is no imminent risk of the populations going extinct, management and monitoring suggestions are provided to ensure these populations persist.