What we do
Queen short-haired bumblebee on clover
Image: Nikki Gammans
The short-haired bumblebee, Bombus subterraneus, is one of 27 bumblebee species native to the UK.
It was once widespread across the south of England, occurring as far north as Humberside, but from the 1960s onwards its population distribution became isolated and patchy.
Its decline was almost certainly the result of the loss of the species-rich grassland habitats on which it depends. It was last recorded near our Dungeness nature reserve in 1988 and declared extinct in 2000.
A population of UK origin survives in New Zealand, where they were introduced in 1895 to pollinate red clover.
The project is working with farmers, conservation groups, small holders and other land owners to create flower-rich habitat within the release area of Dungeness and Romney Marsh.
Our Dungeness reserve is contributing to this through the creation of 4 ha of flower-rich bumblebee habitat from the restoration of arable fields.
The Swedish Threatened Species Unit (ArtDatabanken) has advised that the status of the short-haired bumblebee in Sweden has improved and is no longer red-listed. Southern Sweden was chosen as the source of the bees, following advice from local bee recorders that the population in southern Sweden was strong, and given the similarity in climate between southern Sweden and the UK.
With permission from the Swedish Board of Agriculture (Jordbruksverket), an initial visit to Sweden was made in May 2011 to find suitable locations to collect queen bees. Working with the local bumblebee recorder, suitable areas of habitat were visited and bees collected for disease screening.
Natural England has undertaken a full Disease Risk Assessment and Disease Management Plan in order to meet IUCN guidelines on species reintroductions.
This involves a protocol to be followed for reducing the risk of disease transmission. FERA has approved the import of the bees into the UK and the Natural England licencing unit has granted a license to release them.
It is only necessary to reintroduce queen bees in the spring as they will have mated prior to hibernation, so will be fertile and able to establish nests after gathering enough pollen and nectar.
Worker bees develop from the first eggs and they forage for the queen. She then lays more eggs that develop into males and new queens. Only the new queens go into hibernation to establish the next generation of bumblebees; the old queens, workers and males all die.
In spring 2012, with continuing permissions and the co-operation of bee experts in Sweden, 89 queen bees, freshly emerged from hibernation, were collected from two areas of Skane in southern Sweden where good numbers of short-haired bumblebees were found in 2011. The bees were collected from two 30m long transects which were 40 kilometres apart.
Only a few queens were taken from each location along the transects to make sure there was a minimal impact on the population at any one locality. They were checked for mites and American foulbrood disease by a registered vet and honeybee inspector in Sweden prior to the issuing of a heath certificate to allow their transportation to the UK. After two weeks in quarantine at Royal Holloway, University of London, 51 of the heathiest bees were released at RSPB’s Dungeness nature reserve on 28 May 2012.
Teams of volunteers and RSPB staff carried out surveys along transects to look for the bees and record other species using the flower-rich habitats on the reserve and in the surrounding farmland. Unfortunately, the following weeks were some of the wettest on record and despite intensive searching they were only sighted in the week after they were released. It is still possible that some survived but have not been seen, as they can disperse over a wide area.
In spring 2013 this was repeated with 49 queens released at Dungeness on 3 June. With improved weather they had a better chance of surviving, and we know that at least two queens successfully nested as seven worker bees of two colour forms were seen during July.
After two more releases in 2014 and 2015 there were further successes, with the number of workers seen at any one time on RSPB reserves increasing in 2015.
It is hoped that the bees are completing their life-cycle by producing new queens and males but so far none have been sighted. Given the bees' ability to fly over long distances, they may be very thinly spread over a wide area of countryside.
Further releases are planned for 2016 to build up a genetically diverse population.
To date the project has had enormous success with bumblebee habitat creation prior to the reintroduction of the short-haired bumblebee.
The project has created, advised and assisted in the management of over 850 hectares of flower rich habitat within the release area of Dungeness and Romney Marsh. The RSPB’s Dungeness nature reserve is contributing to this through the creation of 4 ha of flower-rich bumblebee habitat from the restoration of arable fields.
The success of the habitat creation is being assessed through survey transects to record bumblebee species and numbers seen. Excitingly, the first worker bees were seen in the summer of 2013, providing proof that queens had successfully nested and produced young. Worker bees were then seen in each of the following two years, with three seen together on the RSPB's Dungeness reserve in July 2015.
In addition, five of the UK's most threatened species of bumblebee have been recorded on the transects. England’s rarest bumblebee, the shrill carder bee, has returned to the Dungeness area after a 25-year absence and the large garden bumblebee has come back after ten years. Watch our film.
The project has played a large part in raising awareness of bumblebee declines through events and publicity.
Dr Jane SearsBiodiversity Projects OfficerE-mail: firstname.lastname@example.org