Iconic Bees: 12 reports on UK bee species
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
Iconic Bees:
12 reports on UK
bee species
Bees are vital to the ecology of
the UK and provide significant
social and economic benefits
through crop pollination and
maintaining the character of
the landscape. Recent years
have seen substantial declines in
many species of bees within the
UK. This report takes a closer look
at how 12 ‘iconic’ bee species are
faring in each English region, as
well as Wales, Northern Ireland
and Scotland.
Authors Rebecca L. Evans and Simon G.
Potts, University of Reading.
Photo: © Amelia Collins Contents 1 Summary 2 East England Sea-aster Mining Bee 6 East Midlands Large Garden Bumblebee 10 London Buff-tailed Bumblebee 14 North East Bilberry Bumblebee 18 North West Wall Mason Bee 22 Northern Ireland Northern Colletes 26 Scotland Great Yellow Bumblebee 30 South East England Potter Flower Bee 34 South West England Scabious Bee 38 Wales Large Mason Bee 42 West Midlands Long-horned Bee 46 Yorkshire Tormentil Mining Bee
Summary Through collating information on the 12 iconic bee species, common themes have
emerged on the causes of decline, and the actions that can be taken to help reverse it.
The most pervasive causes of bee species decline are to be found in the way our
countryside has changed in the past 60 years. Intensification of grazing regimes, an
increase in pesticide use, loss of biodiverse field margins and hedgerows, the trend towards
sterile monoculture, insensitive development and the sprawl of towns and cities are the
main factors in this.
I agree with the need for a comprehensive Bee Action Plan led by the UK Government
in order to counteract these causes of decline, as called for by Friends of the Earth. But
households and communities, local authorities and agencies, and devolved governments
can also make a significant difference. And while it’s critical that the UK Government acts
to reverse the decline in all bee species, some of the iconic bees identified in this research
also have very specific and local needs.
Overarching Recommendations include:
> Governmenti, local wildlife groups and local authorities to raise awareness of bee
diversity and pollinators’ ecological and economic importance.
> Government to ensure further surveying and monitoring of wild bees to establish more
accurate population numbers and changes.
> Government to ensure there is enough expertise and advice available for landowners,
local authorities and farmers to inform bee-friendly land management.
> Government, local wildlife groups and local authorities to promote sympathetic
grazing regimes to landowners and farmers that ensure adequate bee-friendly forage
availability until the end of summer/early autumn.
> Government to encourage farmers to take-up the most beneficial Agri-Environment
options such as sowing pollen and nectar mixes, buffer strips, wildflower margins,
sympathetically managed hay meadows and semi-natural grasslands. These options
need to be widely available and financially viable for the landowner.
> Government to set quantitative targets for the reduction of all pesticide use and to
encourage the use of alternative pest management methods.
> Government to ensure protection for sites of importance to rare and threatened bees,
for example with SSSI designation.
> Local planning authorities to ensure that biodiversity priority lists and action plans are
consulted as part of their consideration of any planning or development proposals,
and damage to priority species and habitats avoided.
> Government and local planning authorities to encourage developers to include bee-
friendly habitat when carrying out developments.
> Planning authorities to identify important populations of rare or threatened bee
species and significant sites for bees in their local plans, ensuring that they are
adequately protected.
> Local authorities and local wildlife groups to encourage gardeners and local
communities to grow more wild and/or bee-friendly plants in open spaces and
gardens.
> Local authorities to grow more bee friendly plants in parks and open spaces.
These actions cut across various policy areas and involve multiple actors. Friends of the
Earth’s call for a Bee Action Plan is primarily aimed at the UK Government, but would
involve devolved governments, key stakeholders such as farmers, bee keepers, local
authorities and agencies to advise on its content and implementation.
Simon G. Potts,
Professor of Biodiversity and Ecosystem Services,
School of Agriculture,
Policy and Development,
University of Reading.
i
Government refers to UK Government or where powers are devolved to the relevant devolved Government
1
East England Sea-aster Mining Bee
Common name:
Sea-aster Mining Bee
Scientific name:
Colletes halophilus
Description
This attractive solitary bee belongs to a group known as ‘mining bees’, a term relating to
their habit of excavating burrows in the earth in which to nest.
The females are 11-14mm long with rich reddish brown hair on the thorax and black
abdomen with distinct pale hair bands. The males are similar but smaller at 8-12mm
and generally paler.
Distribution and Status
> C. halophilus is globally very limited in its distribution, being found only in low-lying
coastal areas of the eastern English Channel, the Atlantic coast of France and the
southern North Sea.
> Within the UK it is distributed along suitable coasts of the east and south of
England from Spurn point to the very east coast of Dorset.
East England is a key area > East Anglia and the Thames Estuary are particularly significant strongholds. Due
for the Colletes halophilus. to such a localised worldwide distribution, it could be argued, in a global context,
© Map copyright: See back cover.
that it is the UK’s most ‘important’ bee species.
> The species is restricted to the coast, occurring at near sea-level habitats such as
saltmarsh, sea walls, dune systems, low cliffs and behind beaches.
Colletes halophilus is on the England Biodiversity Strategy S41 species list (previously
the UK List of Priority Species and Habitats under the UK Biodiversity Action Plan (UK
BAP)) and although not included in the Red Data Book by Shirt (1987), was later revised
by Falk (1991) to Nationally Notable (Na).
Ecology and Behaviour
> The female C. halophilus excavates short, curved nesting burrows from exposed bare
soil at the end of which she builds a cluster of five or six nest partitions or ‘cells’. In
each cell the female lays an egg provisioned with pollen and a little nectar (normally
from Sea Aster) that the growing bee (larva) will feed on.
2
> It will then undergo metamorphosis, forming a pupa in which it totally transforms,
Key Facts: later breaking through its cell to emerge from the burrow as the adult. Females will
nest very close together at the same site in an aggregation (sometimes numbering
> Could be argued, in a global
thousands); however they still ‘work’ completely independently from one another and
context, as being the UK’s most
are not social insects.
‘important’ bee species.
> Emergence of the first individuals takes place around mid-August; the males first,
> The name halophilus means ‘salt
followed by the females. As females emerge, large numbers of males can sometimes
loving’ after the habitat it is found
be seen ‘mobbing’ the females, clustering into what is known as a ‘mating ball’. After
in, saltmarsh.
mating takes place the females start building their nest burrows, laying eggs and
> Saltmarsh has declined by 50% provisioning them with food.
worldwide.
> The bee not only needs to collect pollen for its young, it needs this protein itself plus
Best places to see: The saltmarshes energy from sugary nectar in order to remain active as long as possible. Individuals of
of north Norfolk and North Essex this species gather nectar from a wide range of plant species but the females will only
such as the Blackwater estuary. collect pollen from plants of the family Asteraceae, namely Sea Aster (Aster tripolium).
> The foraging and nesting activity of C. halophilus will continue until around the middle
of September or occasionally early November by which time all individuals will have
died; the males first followed by the females. The young overwinter in their cells and
emerge in the summer as their parents did the previous year and the whole cycle
begins again.
> Over a quarter of British bee species are known as cleptoparasites or ‘Cuckoo Bees’.
This means that they enter nests of other bees and lay their own egg in an occupied
cell, which in turn hatches and eats both host larva and pollen provision. The cuckoo
bee Epeolus variegatus is the parasite of C. halophilus.
Causes of Decline and Conservation
> Due to this bee’s habit of nesting almost at sea level, the most obvious threats to its
survival are habitat loss due to coastal development (sea defences, urbanisation etc.),
erosion and sea-level rise.
> Worldwide saltmarsh habitat has declined by an estimated 50% (Mossman et al,
2012). The JNCC reports 58% of current UK saltmarsh to be in ‘favourable’ condition.
> Saltmarsh is a protected habitat under the EU Habitats Directive and as a
consequence any losses of the habitat due to erosion or urbanisation etc. must either
be restored or replaced under the commitments of the directive.
> The driving factors of decline can cause loss of the required stable substrate in
which the bees nest and loss of its preferred food-plant Sea Aster. It is made even
more vulnerable in having an extremely localised distribution and these factors are
applicable throughout its global range, not just the U.K.
> The effects of habitat loss on this species take time to come about, this is because the
Sea Aster it thrives on occurs in the centre of saltmarsh and so is not the first bit of
land to be lost to erosion, sea-level rise etc. This may explain why large-scale declines
have not yet been recorded.
> The east of England is a stronghold for C. halophilus because there are larger areas
of saltmarsh and less development than the south coast. The north Norfolk coast is
particularly suitable since the mix of saltmarsh and sand dunes provides a stable mix
of food plant and nesting habitats.
> In both 2010 and 2011, investigations into the nesting requirements of Colletes
halophilus were carried out by Hymettus Ltd at various sites in Essex and Suffolk.
It was discovered that the bee was exploiting a number of different areas within
the coastal habitats, namely the zone between sand dune and saltmarsh as well as
Marram grass locations (Lee, 2011). In these areas it was mainly nesting in moist
sandy substrate but aggregations have also been recorded in clay-based sea defences.
At the sites where nests were not kept moist, it is suggested that tunnels are held
together by the root systems of the Marram grass. This information is useful for
planning future surveys of existing or potential populations, whether for developers
or for general recording/monitoring purposes.
3
> There is a land management option which could promote saltmarsh habitat
for C. halophilus and that is the relatively new practice of ‘managed retreat’ or
‘managed realignment’. This involves removal of man-made sea defences, allowing
the land to act as a natural barrier between the sea and inland areas. It was
developed to both stabilise the coast and help mitigate the loss of saltmarsh and
other intertidal habitats.
> Some of the organisations that have initiated managed realignment projects
include the Essex Wildlife Trust, RSPB and Environment Agency. Sites in Essex
where schemes have taken place include Tollesbury and Abbott’s Hall Farm in the
Blackwater Estuary which covers almost 280ha.
> There have been records of C. halophilus turning up at a managed retreat site in
Brancaster, Norfolk (Strudwick, personal communication, February 11, 2012) just
two years after creation.
> In 2012 the University of East Anglia published results of a study (Mossman et
al, 2012) that compared floristic biodiversity between saltmarsh sites that were
either natural, created by storm surges or man-made (e.g. through realignment
schemes). They discovered that man-made sites (one site was the marshes at the
above mentioned Brancaster realignment) were significantly less biodiverse than
the natural saltmarshes and that therefore it could be argued that commitments
under the EU Habitats Directive were not being met. They note that sites were
mainly deficient in ‘higher’ saltmarsh species and suggested that many man-made
marshes could be improved by both planting more mid and upper level saltmarsh
plants or by raising the elevation of the marsh.
> It should be remembered that since development of the saltmarsh (and hence
Sea Aster) habitat can take decades, coupled with the fact that these sites may
be inadequately monitored (Wolters et al, 2012), it still remains difficult as yet to
know how successful sites of managed retreat have been for the species. However
the species has been recorded at some of these sites, and even man-made
Top: Sea aster flowers. © Simone Truniger
Bottom: Saltmarsh, Suffolk. © Thinkstock
saltmarsh must be better than no saltmarsh.
> All these issues make results of the practice unknown or unpredictable and
as a consequence, it is slow to be taken up as a management option (Morris et
al, 2004).
> Hymettus Ltd have utilised data from the Environment Agency on coastal erosion
and sea defences in order to map zones within the bee’s range that are at risk
from saltmarsh loss due to sea level rise and also to locate areas where managed
realignment schemes may be beneficial (Lee, 2011).
Recommendations
The report authors agree with the need for a Bee Action Plan to address urgent actions
to be taken by the UK government, as called for by Friends of the Earth’s Bee Cause
campaign.
Further potential strategies to assist C. halophilus and in turn its endangered cuckoo bee
Epeolus variegatus include the following:
> UK Government to introduce a national programme to monitor populations of wild
pollinators including declining, threatened or rare bee species such as C. halophilus
> Local recorders and/or wildlife organisations to continue survey work of existing
populations in the area and identify any new sites where the species was previously
unknown.
> Local recorders and wildlife groups to record the species and submit the data to
the Bees, Wasps and Ants Recording Society (BWARS).
> The public, local recorders and NGOs/wildlife groups to continue to raise
awareness of C. halophilus with other members of the public, local conservation
organisations, local authorities, local MPs and land owners/managers where the bee
occurs or where it could potentially occur.
4
> Government agencies, local wildlife organisations and local authorities giving
advice to landowners in the above areas (and those surrounding) to promote the
bee’s required habitat and forage, e.g. to install a grazing/mowing regime that
avoids removing flowers until early autumn, leaving/clearing of some bare patches
of soil for nesting habitat and sowing of Sea Aster if feasible.
> If any management is undertaken then monitoring of its effectiveness by local
authorities, local recorders and local wildlife groups should be undertaken.
> Local recorders and wildlife groups to identify any corridors of potentially suitable
habitat between existing populations and relate this to the species’ dispersal distance
and propensity. This information can then be used to determine if colonisation of
these sites would be feasible given appropriate management of the corridor.
> If a corridor is established then it should be monitored by local authorities, wildlife
groups, or recorders. If it is deemed particularly important, the local authorities
Photo: © Steven Falk should incorporate it into their local plans to provide protection for the corridor and
the species dependent upon it.
> MPs, planning authorities and councillors to support proposed saltmarsh
recreation schemes and ensure that extra conservation measures such as planting
of mid and high level saltmarsh plants and having areas of raised elevation are
implemented at the same time.
> 80% of the UK’s saltmarsh falls within SSSI and is protected under the EU Habitats
Directive. However local authorities should record any important sites (either
already in existence or identified by the further survey work) for the bee in their
local plans and ensure policies and mitigation plans are in place to protect these
populations when development is proposed.
> UK Government and local authorities to encourage developers to include bee-
friendly habitat in new developments. This would be in-line with the National
Planning Policy Framework which aims to achieve biodiversity gain. For example,
over the next 18 months the Environment Agency plans to rebuild flood defences
near Breydon Water. It will simultaneously create nesting habitat for C. halophilus
and will survey for the species before and after completion (Strudwick, personal
communication, February 11, 2012).
> Local people in the region could also join local habitat creation campaigns such as
the Friends of the Earth ‘Bee Worlds’ project and also sign their petition for a Bee
Action Plan.
References
Edwards, M. (2009) Aculeate Information Sheets: How the habitat requirements of BAP aculeates relate to
their HAP; Colletes halophilus, a bee of saltmarshes. Hymettus.
Else, G.R. & Field, J.P. (2001) Colletes halophilus. BWARS Species Page. www.bwars.com.
JNCC (2010) Colletes halophilus .UK Priority species Pages V2.
Lee, P. (2011) Hymettus Ltd Research Report for 2011. Hymettus Ltd.
Mossman, H.L., Davy, A.J. & Grant, A. (2012). Does Managed Coastal Realignment Create Saltmarshes with
‘Equivalent Biological Characteristics’ to Natural Reference Sites? Journal of Applied Ecology 49 (6), pp.1446-1453.
Morris, R. K. A., Reach, I.S., Duffy, M.J., Collins, T.S. & Leafe, R.N. (2004) On the Loss of Salt Marshes in South-
east England and the Relationship with Nereis diversicolor. Journal of Applied Ecology 41(4), pp.787-791.
Strudwick, T. (2012) Personal Communication.
Williams, R. (ed.)(2012) An Introduction to Bees in Britain. Bees Wasps & Ants Recording Society.
5
East Midlands Large Garden Bumblebee
Common name:
Large garden or Ruderal
Bumblebee
Scientific name:
Bombus ruderatus
Description
Key Facts:
> Britain’s largest bee This is Britain’s largest bumblebee with a long face and extremely long tongue. It
strongly resembles the more widespread Small Garden Bumblebee (Bombus hortorum)
> Despite showing an estimated
with a yellow band either end of its thorax, a single yellow band at the top of the
80% decline in sites recorded over
abdomen (often broken or faint) and a white tail, however its hair is shorter and ‘neater’
the last century, (Anon, 2010),
and the yellow bands tend to be duller and more mustard in colour. Also, unlike the
it is now showing a comeback,
Small Garden Bumblebee, it has a completely black form.
particularly in the East Midlands
which is the northern edge of its
range.
Distribution and Status
Best places to see: Many parts of the
East Midlands but particularly fenland
> B. ruderatus is one of several internationally declining bumblebee species.
and other wet grassland areas.
Its precise range is quite difficult to define since some historic records are likely to
Two examples of particularly good
be misidentifications of other very similar bumblebee species. However it is basically
sites are Gosberton Clough, South
distributed across central and southern Europe.
Lincolnshire and Easton-on-the Hill,
Northamptonshire. > In the British Isles (it is only present in England) it is reported to be lost from about
80% of its former range over the last century, confining it to central and southern
areas, namely the East Midlands, Cambridgeshire and the Fens (Anon., 2010), as well
as some southern counties such as Hampshire and Wiltshire.
> Interestingly there are areas of the UK where populations now seem to be locally
increasing, particularly within the East Midlands which is the current northern limit
of this range.
> B. ruderatus’ preferred habitat is flower-rich meadows of river valley systems,
fenlands and other wetlands. This is due to the presence in these areas of White
Dead-nettle, Comfrey, Marsh Woundwort and Yellow Iris on which it likes to forage.
It also has a strong liking for Clover and other leguminous plants and so is also
found on farmland that contains margins and ditches rich in these species.
Bombus ruderatus is on the England Biodiversity Strategy S411 species list (previously
the UK List of Priority Species and Habitats under the UK Biodiversity Action Plan (UK
BAP) and although not included in the Red Data Book by Shirt (1987), is listed by Falk
(1991) as Nationally Notable or Nationally Scarce (Nb)2.
1
This is a list of species and habitats identified to be of biodiversity conservation priority in England that should be taken into
consideration during planning and development initiatives.
2
A status given to species found in only 31-100 10km grid squares of the UK.
6
Ecology and Behaviour
> Queen B. ruderatus emerge from hibernation between April and June and start looking
for a suitable nest site. This will usually be underground (possibly quite deep) either
under vegetation or as is often the case in a disused small mammal burrow. Either
the old burrow/nest is ‘rearranged’ or possibly nearby soft dry materials such as grass
and moss are gathered into a ball and used to insulate the nest. The queen makes a
chamber inside with a single entrance. She secretes wax from her abdomen and forms
it into a pot which she fills with nectar and next to it forms a wax covered lump of
pollen (usually from plants of families Fabaceae, Lamiaceae, Scrophulariaceae (now in
Orobanchaceae and Plataginaceae), Iridaceae or Boraginaceae), inside which she lays
around 8-16 eggs.
> The queen incubates her eggs and after a few days these hatch and the larvae begin
feeding on the pollen which must be replenished by the queen as they grow. After
a couple of weeks, the larvae spin a cocoon and pupate, and two more weeks after
this they hatch into the first all-female ‘worker’ bumblebees. Some of these will stay
behind to help rear the next batch of workers but most will leave the nest and forage
to bring back pollen and nectar for the nest workers and developing young.
> This cycle continues until around June when the queen switches from producing
workers to producing males and new queens. These emerge from the nest to be seen
between about July and October. The young queens feed purposefully on pollen and
nectar in order to build-up fat reserves. Around this time, they also set about looking
for a mate and after mating, aim to find a suitable hibernation spot which is usually
some loose soil in which they can burrow and form a small chamber in which to
overwinter, living off the fat reserves they laid down. What remains of the colony i.e.
workers, males and the old queen expire from exhaustion. The cycle begins again the
following spring.
> Over a quarter of British bee species are known as cleptoparasites or ‘Cuckoo Bees’.
This means that they enter the newly established nests of other bees, usually kill the
queen and then lay their own eggs. The young, reared by the host workers will only
ever be fertile females or males as cuckoo species do not need their own workers.
The cuckoo bumblebee Bombus barbutellus is the parasite of Bombus ruderatus.
Causes of Decline and Conservation
> The main threat and cause of decline to this bee is habitat loss through on-going
agricultural intensification and land use change.
> Like several other bumblebee species, it requires large areas or whole landscapes
that provide plenty of nesting sites and produce in abundance a succession of the
plant species it forages on throughout all stages of its life cycle.
> Optimal habitat has been lost through conversion of flower-rich grassland, biodiverse
Photo: Bombus ruderatus male. brownfield sites, field margins, ditches and wetlands to more intensive agricultural
Avon Dassett, Warwickshire. © Steven Falk and grassland systems, plantation, scrubland and urban developments.
> One of the biggest factors in habitat loss for B. ruderatus is the intensification of
mowing and grazing regimes, which remove the bee’s forage plants before the end
of its life cycle.
> Due to the above mentioned habitat loss and fragmentation; this bee has
disappeared from an estimated 80% of its former range in the UK. However as
previously stated, Bombus ruderatus is now actually shown to be increasing locally
in the last couple of decades, particularly within the Midlands. For example, it was
rediscovered in Warwickshire in 1999 near Shipston-on-Stour after being considered
extinct in the county and Falk (2011) described its subsequent increase as ‘perhaps
the most pronounced increase anywhere in Britain’ of the species. There have been
similar recent population increase observations in the East Midlands in places such
as South Lincolnshire on the edge of the fens (see below).
> It is worth looking at why records of this bee are showing an increase in certain
7
areas of the East Midlands as this may inform strategies to help the bee elsewhere.
There are a couple of potential explanations: firstly it should be noted that
the sympathetically managed areas of the Fens would probably have been an
important refuge and therefore key to its survival during the main period of
agricultural intensification in the UK and will continue to be so in the surrounding
sea of intensive farmland. This cannot be the only explanation however since the
bee is now shown to be doing well in farmland also. This has been attributed to
stewardship schemes that aim to enhance agricultural landscapes for wildlife, with
pollen and nectar mix options that include a high proportion of clovers (Edwards,
2013). B. ruderatus is showing a strong preference for areas sown with these
mixes so that in some formerly ‘bumblebee poor’ areas where these mixes have
subsequently been sown, B. ruderatus appears to be returning (Anon, 2010). It
should also be noted that historically, this bee may have been recorded as similar
species in certain areas, and so estimating declines and increases in those areas can
be difficult.
> In a specific initiative in South Lincolnshire, the Black Sluice Internal Drainage Board
commissioned a report on an area of their land (includes a mile of ditch), part of
Risegate Eau, near Gosberton Clough. The area is currently managed by a team
of local volunteers and supports a population of B.ruderatus. The report aimed to
deliver ways to enhance and improve biodiversity in the area and thanks to local bee
recorders’ awareness-raising and advice, is quite heavily geared towards supporting
B. ruderatus. The management plans to achieve the project goals include: only
heavily managing the south side of the bank, leaving the north bank which is rich in
flora, including White Dead-Nettle and only mowing this every other year and even
then not until the very end of the summer. The report also sets out plans to improve
the watercourse by including a small pond which will promote the spread of plants
such as Yellow Iris, Comfrey and Marsh Woundwort on which B. ruderatus thrives.
This strategy will benefit many other bees and insects not just B. ruderatus.
Recommendations
The report authors agree with the need for a Bee Action Plan to address urgent actions
to be taken by the UK government, as called for by Friends of the Earth’s Bee Cause
campaign.
Further potential strategies to assist B. ruderatus and in turn its endangered cuckoo bee
Bombus barbutellus include the following:
> UK Government to introduce a national programme to monitor populations of wild
pollinators including declining, threatened or rare bee species such as B. ruderatus.
> Local recorders and/or wildlife organisations to continue survey work of existing
populations in the area and identify any new sites where the species was previously
unknown.
> Local recorders and wildlife groups to record the species and submit the data to
Comfrey flower. © Thinkstock the Bees, Wasps and Ants Recording Society (BWARS).
> Wildlife groups to continue to raise awareness of B. ruderatus with local authorities,
local MPs and land owners/managers where the bee occurs or where the species is
either: already found, may occur in or could potentially inhabit in the future.
> Government agencies, local wildlife organisations and local authorities giving
advice to landowners in the above areas (and those surrounding) to promote the
bee’s required habitat and forage e.g. sowing of White-Dead Nettle, Clovers and
Comfrey, to install a grazing/mowing regime that avoids flowers being removed
until late summer/early autumn and also to encourage management of ditches and
other waterways including clearing excess vegetation to encourage growth of Marsh
Woundwort, Yellow Iris and Comfrey.
> Government agencies, and local authorities to advise farmers of potentially
beneficial Agri-Environment options such as pollen & nectar mix sowing (with
addition of Clovers) and sympathetic grazing regimes (especially with reference
to areas next to ditches and other waterways) that ensure there are always the
8appropriate (and reachable) resources throughout the bee’s life cycle, i.e. at least
April to September.
> If any management is undertaken then monitoring of its effectiveness by local
authorities, local recorders and local wildlife groups should be undertaken.
> Local people to plant ‘bee-friendly’ plants throughout the bee’s life cycle in their
gardens, particularly Clover, White-Dead Nettle and Comfrey.
> Local authorities should record any important sites (either already in existence
or identified by the further survey work) for the bee in their local plans and ensure
policies and mitigation plans are then in place to protect these populations.
> UK Government and local authorities to encourage developers to include bee-
friendly habitat in new developments. This would be in-line with the National
Planning Policy Framework which aims to achieve biodiversity gain.
> Local people in the region can join local habitat creation campaigns such as the
Friends of the Earth ‘Bee Worlds’ project and also sign their petition for a Bee Action
Photo: Bombus ruderatus male on mallow, Fens, Plan.
Norfolk, June 2007. © Nick Owens.
References
Anonymous (2010) Species Management Sheet: Large Garden Bumblebee (Bombus ruderatus). Buglife.
Edwards, M. (2001) Bombus ruderatus. BWARS Species Page. www.bwars.com.
Edwards, M. (2013) Personal Communication.
Falk, S. (1991) A Review of the Scarce and Threatened Bees, Wasps and Ants of Great Britain. Research and
Survey in Nature Conservation, Peterborough.
Falk, S. (2002) Rare Bumblebees: Bombus humilis and B. ruderatus. Warwickshire, Coventry and Solihull Local
Biodiversity Action Plan. Warwickshire.gov.uk/biodiversity.
Falk, S. (2011) Warwickshire’s Bumblebees. Warwickshire County Council & Warwickshire Biological Records
Centre.
Goulson, D. (2010) Bumblebees: behaviour, ecology and conservation. 3rd Ed. Oxford University Press.
Hebdon, L. (2013) Personal Communication.
JNCC (2010) Bombus ruderatus.UK Priority species Pages V2.
Roberts, S. (2013) Personal communication.
Scarborough, H. (2012) Assessment and Habitat Enhancement of Gosberton Risegate Eau, Gosberton Clough,
south Lincolnshire. Scarborough Nixon Associates Ltd.
Williams, R. (ed.)(2012) An Introduction to Bees in Britain. Bees Wasps & Ants Recording Society.
9London Buff-tailed Bumblebee
Common name:
Buff-tailed Bumblebee
Scientific name:
Bombus terrestris
Description
A fairly large bumblebee with a dark yellow stripe at the front of its thorax, another at
the front of its abdomen and a white coloured end to its tail. Workers can be very hard
to separate from workers of the closely related white-tailed bumblebee Bombus lucorum
but the queens can separated by having a buff tail rather than white and the males in
having a black face rather than yellow.
Distribution and Status
> B. terrestris is found throughout Europe and mid to northern Asia as far east as
northern Mongolia and as far south as North Africa, albeit at high altitudes. This
bumblebee is also found in Australasia and South America, either as the result of
deliberate introduction or as a commercial escapee.
> Within the U.K it also has a widespread distribution but particularly in England and
is found in almost every lowland habitat.
London is a key area for the
Bombus terrestris. > This is not a rare or threatened bee.
© Map copyright: See back cover.
Ecology and Behaviour
> B. terrestris queens as a rule emerge from hibernation between February and April
(dependent on weather) and start looking for a suitable nest site which will be a
disused small mammal burrow underground. Soft dry materials such as grass and
moss are gathered into a ball and used to insulate the nest. The queen makes a
chamber inside this material with a single entrance. She secretes wax from her
abdomen and forms it into a pot which she fills with nectar and next to it a wax
covered lump of pollen inside which she lays around 8-16 eggs.
> The queen incubates her eggs and after a few days these hatch and the larvae
begin feeding on the pollen which must be replenished by the queen as they grow.
After a couple of weeks the larvae spin a cocoon and pupate and two more weeks
after this hatch into the first all-female ‘worker’ bumblebees. Some of these will
stay behind to help rear the next batch of workers but most will leave the nest and
forage to bring back pollen and nectar for the nest workers and developing young.
10Workers visit a whole range of flowers and are thought to have the most diverse
Key Facts: diet of any British bumblebee (Edwards, 2009).
> The U.K’s only observed wild > Generally, this cycle continues until around June when the queen switches from
winter-active bee. producing workers to producing males and new queens (there is a wild-living
commercial sub-species however that produces mostly males and many colonies
> The colonies of this bumblebee
produce no queens at all). These emerge from the nest to be seen between about
can contain over 500 individuals.
July and October. The young queens feed purposefully order to build-up fat reserves.
Around this time they also set about looking for a mate and after mating aim to find
Good places to see: In almost any
a suitable hibernation spot which is usually some loose soil in which they can burrow
lowland habitat of Britain and Ireland.
and form a small chamber in which to overwinter, living off the fat reserves they laid
In winter the most likely places to
down. What remains of the colony i.e. workers, males and the old queen expire from
see this species is in the gardens and
exhaustion. The cycle begins again the following spring.
amenity shrub areas
of towns and cities. > Over a quarter of British bee species are known as cleptoparasites or ‘Cuckoo Bees’.
This means that they enter the newly established nests of other bees, usually kill the
queen and then lay their own eggs. The young, reared by the host workers will only
ever be fertile females or males as cuckoo species do not need their own workers.
The cuckoo bumblebee Bombus vestalis is the parasite of Bombus terrestris (In
England and now recently also recorded in Scotland).
Changes in Behaviour
> Up until around the late 1990’s all B. terrestris (like all other bumblebees) were
thought to have one generation per year as described in the above Ecology and
Behaviour section. However over about the last 15 years, individuals have been seen
foraging in the winter months also.
> Whereas queens would normally go into hibernation until early spring, some are
now only hibernating (if at all) for a short while, waking early and going into nest
establishment, rearing a winter-active colony which will produce a new queen to found
another colony in spring. It is not yet really known what how long these queens are
hibernating for or what really happens between summer and winter colonies and this
needs to be the subject of future study (Ings, 2013).
> This behaviour is largely observed in towns and cities of the south of England,
notably London (but recorded as far north as Hull) where there is a plentiful supply
of energy-rich, winter-flowering ornamental plants such as Arbutus, Mahonia and
winter-flowering heather. It has also been observed in some rural areas specifically
where there is an abundance of the above mentioned plants.
> The causes of this change in behaviour are probably a combination of recent
warmer winters and also an increase in winter-flowering plants in parks and gardens
that can provide adequate pollen and nectar sources that would not be available
in the wild. There is also a possibility that these wild B. terrestris may be hybridising
with a commercial sub-species which is known to produce two generations a year.
Photo: Bombus terrestris queen on Thrift, Weyborne, > In 2010 work was undertaken by Queen Mary’s University, London to try and
Norfolk. © Nick Owens. determine what the winter bumblebees were feeding on and whether they were
finding adequate forage for colony survival. The research involved a combination of
radio tagging a colony of a commercial type of B. terrestris to see how much forage
it was managing to collect along with standardised observations of B. terrestris in
Kew Gardens to see what they were feeding on.
> The results showed that most visits were to Mahonia, winter-flowering heather,
strawberry tree (Arbutus), Clematis, Rhododendron and honeysuckle. Rates and
amount of forage collected indicated that bees could match, if not surpass, the
foraging capabilities of spring /summer colonies (Stelzer et al, 2010). The reason
Mahonia is ideal for winter bees is because there are different varieties that produce
lots of nectar and different times (from October – March) so there is a good nectar
supply throughout the winter (Ings, 2013).
11Causes for Concern
> Although it seems unusual behaviour here, in the warmer parts of the continent,
sub-species of Bombus terrestris regularly produce two or more generations per year,
one of which will be active over winter.
> As previously discussed, the change in behaviour of B. terrestris could be linked to
climate change, however much more research and data collection would need to
be carried out before such assumptions are made. Carlton (2012) notes that there
is even a record of the phenomenon from 1957 and suggests that it could be a
behaviour that has always been going on in warmer winters but it has simply gone
unnoticed. If it was taking place historically and was unnoticed then it would have
been a pretty rare phenomenon and it is certainly more common now (Ings, 2013).
> Stelzer et al (2010) notes that even though it might be tempting for the public
to grow winter-flowering plants to ‘help’ the winter bumblebees, this may not
necessarily be beneficial. This is because if the number of winter colonies increases,
the new queens produced from them may occupy most of the optimal nesting
habitats in those areas, thereby out competing queens of other bumblebee species
that are looking for nesting sites when they emerge from hibernation in the spring.
Again, more research is needed.
> This behaviour could also increase the density of bee parasites over winter which
could subsequently increase the spread of these parasites to the spring colonies
(Ings, 2013).
> It is also a risky strategy for the bees because if the winter turns particularly bad (as
seen the last few years), colonies can be wiped out. This is not really a problem at
the moment since so few colonies are winter active but if the proportion of winter
colonies increases there could a detrimental effect of the B. terrestris population
(Ings, 2013).
Top: Mahonia flowers © Thinkstock
> If winters continue to get warmer, other pollinators (particularly other species of
Bottom: Garden, South London © Amelia Collins
bumblebee) may also start producing winter colonies and this has the potential to
cause plants to flower at other times of the year, producing a change in the overall
plant-pollinator system.
Research and public action needed
> The key to finding out if whether and how B. terrestris is responding to warmer
winters and also if winter-active pollinators will have an impact on the plant-
pollinator system as a whole in the U.K is simply to build extensively on the
preliminary research that has already been done.
> The public can also help by submitting any records they have of winter-active bees.
The Bees Wasps and Ants Recording Society (BWARS) is asking people to submit
records and if they can add any additional information that can help answer the
following questions:
1. Where in Britain (or Ireland) does winter activity occur?
2. Are species other than Bombus terrestris involved?
3. Is winter activity purely an urban phenomenon?
4. Which species of plants are visited?
5. What is the nature of visitation – nectaring, pollen collecting or both?
6. Which caste or sex is involved in visitation?
7. What are the best weather conditions and temperature for activity?
8. What happens between summer and winter colonies? Are queens active or
hibernating?
Records can be submitted here http://www.bwars.com/index.php?q=content/winter-
active-bombus-terrestris-data-gathering
12Recommendations to help all bees
Bombus terrestris is doing well but many of our wild bee species are facing dramatic
decline.
The report authors agree with the need for a Bee Action Plan to address urgent actions
to be taken by the UK government, as called for by Friends of the Earth’s Bee Cause
campaign.
There are a number of actions that can be undertaken to help wild bees in the UK
in general including:
> UK Government to introduce a national monitoring programme to monitor
populations of wild pollinators including declining, threatened or rare bee species.
Data should also be submitted to the Bees, Wasps and Ants Recording Society
(BWARS).
> Members of public and local recorders to raise awareness of declining bee species
to local conservation organisations, local authorities, local MP and landowners
where the species are either: already found, may occur in or could potentially inhabit
in the future.
> Government agencies, local wildlife organisations and local authorities to
advise landowners to encourage habitat management which promotes bee-friendly
habitat, e.g. sowing bee-friendly plants and to install a grazing/mowing regime
that avoids flowers being removed until late summer/early autumn.
> Government agencies, wildlife organisations and local authorities to encourage
farmers to take up the most beneficial Agri-Environment options such as pollen &
nectar mix sowing and sympathetic grazing regimes that ensure there are always
the appropriate resources throughout the spring and summer.
> If any management is undertaken local recorders and/or local wildlife
organisations to monitor its effectiveness.
> Local people to plant ‘bee-friendly’ plants in their gardens.
> Local authorities to record any important sites for bees in their local plans and
ensure policies are then in place to protect these populations.
> Government and local authorities to encourage developers to include bee-friendly
habitat when carrying out developments and this would fall in-line with the National
Planning Policy Framework which aims to achieve biodiversity gain.
> Local people can join local habitat creation campaigns such as Friends of the Earth
‘Bee worlds’ project and also sign their petition for a Bee Action Plan.
References
Edwards, M. (2009) Bombus terrestris. BWARS Species Page. www.bwars.com.
Goulson, D. (2010) Bumblebees: behaviour, ecology and conservation. 3rd Ed. Oxford University Press.
Ings, T. (2013) Personal Communication.
Ings, T. (2010) Winter-active Bumblebees. Hymettus-BWARS Information Sheet.
Roberts, S. (2013) Personal Communication.
Stelzer, R.J., Chittka, L., Carlton, M. & Ings, T.C. (2010) Winter Active Bumblebees (Bombus terrestris) Achieve
High Foraging Rates in Urban Britain. PLOS ONE. Public Library of Science.
Williams, R. (ed.)(2012) An Introduction to Bees in Britain. Bees Wasps & Ants Recording Society.
13North East Bilberry Bumblebee
Common name:
Bilberry/Blaeberry
Bumblebee
Scientific name:
Bombus monticola
Description
This small bumblebee has a red tail and quite round face with a short tongue. There is a
yellow band across both ends of its thorax (the front one being wider) and the red tail,
although common to several other species of bumblebee, is diagnostic in covering most
of the abdomen in this species. The males can be distinguished from the females by
their yellow-haired faces.
Distribution and Status
> B. monticola is only found at the higher latitudes or altitudes of Western Europe
including parts of Scandinavia, the Alps, the Pyrenees, Northern Italy and the Balkan
mountains.
> It was formerly quite widespread in the British Isles (although never in the South
East) but it is feared that its range may retreat to the North and West.
North East is a key area for
As mentioned, B. monticola prefers high altitude, upland habitats such as mountain
the Bombus monticola. and moorland but is also happy at lower altitudes if at a higher latitude, for
© Map copyright: See back cover. example, it has been recorded at sea-level in Scotland and Northern England.
> There is evidence to suggest it also needs access to grassland habitats and does
not do well in pure moorland alone. There also seems to be a strong affinity with
highland areas rich in Bilberry (one of the bee’s favourite pollen sources).
Ecology and Behaviour
> B. monticola queens emerge from hibernation in April and start looking for a
suitable nest site which may be under vegetation and occasionally just under the
soil surface. Once this is located, nearby soft dry materials such as grass and moss
are gathered into a ball and used to insulate the nest. The queen makes a chamber
inside this material with a single entrance. She secretes wax from her abdomen and
forms it into a pot which she fills with nectar and next to it a wax covered lump of
pollen (almost exclusively from flowers of Bilberry or clover) inside which she lays
around 8-16 eggs.
14> The queen incubates her eggs and after a few days these hatch and the larvae begin
Key Facts: feeding on the pollen which must be replenished by the queen as they grow. After a
couple of weeks the larvae spin a cocoon and pupate and two more weeks after this
> A generally high altitude
hatch into the first all-female ‘worker’ bumblebees. Some of these will stay behind to
bumblebee. The species name
help rear the next batch of workers but most will leave the nest and forage to bring
monticola means ‘mountaineer’.
back pollen and nectar for the nest workers and developing young. These workers
> Strongly associated with the can be seen from May onwards visiting flowers of Bilberry but also Sallow, Bramble,
Bilberry. Raspberry, Bell Heather and legumes such as Clover and Bird’s-Foot Trefoil.
Good places to see: Most upland > This cycle continues until around June when the queen switches from producing
areas with an abundance of Bilberry. workers to producing males and new queens. These emerge from the nest to be seen
Dipton Woods, Northumberland is a between about July and October. The young queens feed purposefully on pollen and
particularly good spot. nectar in order to build-up fat reserves. Around this time they also set about looking
for a mate and after mating, aim to find a suitable hibernation spot which is usually
some loose soil in which they can burrow and form a small chamber in which to
overwinter, living off the fat reserves they laid down. What remains of the colony i.e.
workers, males and the old queen, expires from exhaustion. The cycle begins again
the following spring.
> Over a quarter of British bee species are known as cleptoparasites or ‘Cuckoo Bees’.
This means that they enter the newly established nests of other bees, usually kill the
queen and then lay their own eggs. The young, reared by the host workers will only
ever be fertile females or males as cuckoo species do not need their own workers.
The cuckoo bumblebee Bombus sylvestris is the parasite of Bombus monticola.
Photo: Bombus monticola, Peak District. © Tim Melling
15Causes of Decline and Conservation
> Historically, B. monticola was found in many upland areas of the North East
wherever Bilberry was found in abundance as well as some Forestry Commission and
private forest sites that were planted on acid bog or moorland.
> The main causes of the observed quite rapid decline in B. monticola are thought
to be a combination of habitat loss and degradation as a result of development
or under/over management, as well as possibly effects of climate change, both of
which reduce or eliminate the flowering plants it needs to complete its life-cycle, in
this case, Bilberry and legumes such as Clover and Bird’s-Foot Trefoil.
> Within the North East this bee is probably less affected by habitat loss and
degradation than in other places since areas of upland in this region are less
subjected to those types of pressures. The region also supports a fairly well
connected mosaic of good habitat that the bee should easily be able to disperse
around.
> A local recorder spent the 1990s extensively surveying the uplands of
Northumberland and Durham and from the mid 90s recorded a successional
decline in the bee year on year. He noticed that the declines coincided with a
weather pattern of mild early springs followed by frosts in late spring. This pattern
brings the queen bumblebee out of hibernation in March and April but when the
cold snaps hit at the end of April, their food plants often die. If queens have not
already located and set-up a nest then they are unlikely to survive since their fat
reserves are normally too depleted by that point to go back into hibernation.
> The recorder reported the year 2000 to be the worst for the species and noted its
absence at many of the sites where it was usually seen.
> Unlike in some other parts of its UK range, numbers since then have been very slowly
recovering despite further years since of warm periods followed by cold during the
spring. National Park and Forestry Commission employed bumblebee recorders
Top: Bombus monticola worker on wild thyme, North however still note that the bee remains more thinly distributed than a couple of
Yorks Moors. © Louise Hislop
decades ago.
Bottom: Bombus monticola in flight over a bilberry bush,
Hade Edge, West Yorkshire. © Tim Melling > One of the best places to see B. monticola in the North East is Dipton Woods in
Northumberland; despite suffering the same decline over the 1990s, the population
is still fairly healthy and productive, the site supporting good stands of Bilberry. This
could be because the upland habitats in the North East are healthier and better
connected than in other regions of the UK but it is very hard to say.
> Despite the decline of B. monticola in the UK, it has appeared in Ireland for the
first time over the last few decades, being first recorded in 1974 in the Wicklow
Mountains. It probably arrived there by being blown over from Wales and has since
also established itself in the upland and heathland areas of Carlow, Wexford, Antrim
(probably blown over from Scotland), Tyrone and Derry in Northern Ireland. Due to
its decline in the rest of the British Isles, the Irish populations of B. monticola are
now very important.
Recommendations
The report authors agree with the need for a Bee Action Plan to address urgent actions
to be taken by the UK government, as called for by Friends of the Earth’s Bee Cause
campaign.
Further potential strategies to assist B. monticola and in turn its endangered cuckoo bee
Bombus sylvestris include the following:
> UK Government to introduce a national programme to monitor populations of wild
pollinators including declining, threatened or rare bee species such as B. monticola.
> Local recorders and/or wildlife organisations to continue survey work of existing
populations in the area and identify any new sites where the species was previously
unknown.
16> Local recorders and wildlife groups to record the species and submit the data to
the Bees, Wasps and Ants Recording Society (BWARS).
> Local recorders and wildlife groups to identify any corridors of potentially suitable
habitat between existing populations and relate this to the species’ dispersal
distance and propensity. This information can then be used to determine if
colonisation of these sites would be feasible given appropriate management of the
corridor.
> If a corridor is established then it should be monitored by local authorities, wildlife
groups, or recorders. If it is deemed particularly important, the local authorities
should incorporate it into their local plans to provide protection for the corridor and
the species dependent upon it.
> Wildlife groups to continue to raise awareness of B. monticola with local authorities,
local MPs and land owners/managers where the bee occurs or where it could
potentially occur.
> Government agencies, local wildlife organisations and local authorities giving
advice to landowners in the above areas (and those surrounding) to promote the
bee’s required habitat e.g. sowing/ planting of Bilberry and leguminous plants and
installation of a grazing/mowing regime that avoids removing forage flowers such
as clovers, heathers and vetches until late summer/early autumn but also avoids
undermanaging which would lead to scrub invasion.
> Government agencies and local authorities to encourage farmers near important
B. monticola areas to provide Agri-Environment options to support the bees, such as
pollen and nectar seed mixes of leguminous plants.
> If any management is undertaken then monitoring of its effectiveness by local
authorities, local recorders and local wildlife groups should be undertaken.
> Local authorities should record any important sites (either already in existence
or identified by the further survey work) for the bee in their local plans and ensure
policies and mitigation plans are then in place to protect these populations.
> UK Government and local authorities to encourage developers to include bee-
friendly habitat in new developments. This would be in-line with the National
Planning Policy Framework which aims to achieve biodiversity gain.
> Local people in the region could also join local habitat creation campaigns such as
the Friends of the Earth ‘Bee Worlds’ project and also sign their petition for a British
Bee Action Plan.
References
Eales, H. (2013) Personal Communication.
Edwards, M. (2012) Bombus monticola. BWARS Species Page. www.bwars.com.
Fitzpatrick, U., Murray, T.E., Paxton, R.J. & Brown, M.J.F. (2006) The state of Ireland’s Bees. Northern Ireland
Environment Agency.
Photo: Bombus monticola, in a Dandelion. © Tim Melling Goulson, D. (2010) Bumblebees: behaviour, ecology and conservation. 3rd Ed. Oxford University Press.
Roberts, S. (2013) Personal Communication.
Williams, R. (ed.)(2012) An Introduction to Bees in Britain. Bees Wasps & Ants Recording Society.
17North West Wall Mason Bee
Common name:
Wall Mason Bee
Scientific name:
Osmia parietina
Description
This small but robust black bee (8-9mm) has golden to brown coloured hair covering the
face and thorax. The abdomen is predominantly black with a sparse covering of golden
to pale hairs.
Distribution and Status
> Widely distributed throughout northern Eurasia.
> In the U.K restricted to North West Britain with most recent records from North
West England, north and west Wales and southern and northern Scotland.
> Associated with semi-natural and unimproved grassland (including coastal machair
in Scotland), open post-industrial sites and woodland clearings where there is the
presence of the leguminous plant Bird’s-foot Trefoil which is its main source of pollen
in Northern England and Wales.
North West is a key area O. parietina is listed as Rare1 in the Red Data Book for the British Isles by Shirt (1987)
for the Osmia parietina. and Falk (1991) and is on the England Biodiversity Strategy S41 species list2 (previously
© Map copyright: See back cover.
the UK List of Priority Species and Habitats under the UK Biodiversity Action Plan (UK
BAP).
1
A species which at present is not considered endangered or vulnerable but is at risk or is believed to be rare due to only
recently being discovered.
2
This is a list of species and habitats identified to be of biodiversity conservation priority in England that should be taken into
consideration during planning and development initiatives.
18You can also read
