Bumblebees in Essex and around the world
Ross Gardner, a naturalist based at the Meadowfield Nature Study Centre in Hockley, Essex provides some interesting information about the bumblebee: did you know there is even a ‘cuckoo’ bumblebee? Most importantly, Ross highlights threats to the species that could cause worldwide disruption to food production because of lack of pollination and also suggests ways we can help the survival of this magnificent insect.
Springtime Heralds in need of help!!
Spring is here. Even at the time of writing, with a wintry twist in the tail perhaps still in the offing, spring is definitely here. And how do we tell? It doesn't become spring simply because the calendar tell us so. Nature's boundaries are scarcely so well defined as those delineated by mere people. But nonetheless we will all feel that sense of spring, even as the late winter chill still lingers on.
There will always be those harbingers of the season and we will all have our own favourites. It might be the first violet blooms that peep out from the foliage in the lea of the hedgerow; the earliest butterfly to be roused from its winter dormancy as the sun musters enough heat to chase away the cold; or perhaps the first skylark to send that wonderful trilling song out across the breeze on some crisp, late winter morning. And there is another such herald that simply could be not overlooked - the return of the bumblebees!
As early as February the queens of certain species, namely the buff-tailed (Bombus terrestris) and early (B. pratorum) bumblebees, emerge from hibernation and can be seen buzzing slowly and purposefully low over the ground. They will be looking for suitable nesting sites which with these two species, among others, will often be underground, preferably with plenty of floriferous foraging habitat close by. The various nest sites chosen by different bees is known to include such varied abodes as old mouse holes, bird's nests, wall and tree cavities and even nest boxes!
Bumblebees, like numerous other (but certainly not all) species of bee, wasp and ant are social insects (grouped collectively into the Order Hymenoptera). Whichever the species and whatever the chosen nest site, the queen's mission is the same – to found her colony. She will start by collecting pollen, enough to form a lump in her nest, as big as she is, on which to lay a small amount of eggs. These will give rise to the first workers, who, after pupating, will take on nest building, feeding and foraging duties to accommodate the growing colony.
|Bombus rupestris (2005): a cuckoo bumblebee that parasitizes the nest of Bombus lapidarius (red-tailed bumblebee).|
Not all bumblebees will look to found their own colony. There may be skulduggery afoot! Some, the so-called cuckoo bumblebees, will parasitize the nests of others. A queen cuckoo, which closely resembles its would be host, will gain access to the nest. If successful and accepted by the incumbent workers she will take over the colony, either subduing or killing the host queen. The cuckoo will not even produce her own workers, using instead the original workforce to raise her young.
As the spring draws on other species will emerge. Essex does rather well for bumblebee species. Seventeen of the twenty five British species have recently been recorded here. Although some of these are rare, several are common and are regular visitors to a flower rich garden. As well as the two species named above, the aptly named garden (Bombus hortorum), red-tailed (B. lapidarius) and white-tailed (B. lucorum) bumblebees, and the common carder bee (B. pascuorum) are all likely to grace our gardens with their much appreciated and enjoyed presence.
|Bombus lucorum (2001): white-tailed Bumblebee|
But even for these the future may be uncertain. Recent decades have seen a period of decline for British bumblebees. Several species have become extinct and a further five (at least) are considered to be vulnerable. Even populations of some of the more widespread species have suffered a reduction in the density of numbers. The reasons? Those all too familiar wildlife foes of habitat loss and, along with the indiscriminate use of chemicals so often associated with it, intensive farming.
With the decline of bumblebees come potential problems for the human population. Worldwide, some ninety odd crop plants are fertilised by bumblebees, from apples to avocados, soya beans to celery, kiwis to cucumbers. A lack of bees would cause serious problems with production. No bees...no pollination...no crops!
Bumblebees need flowers and plenty of them, and of course the plants need the bees too. The same implications for human crops apply to wild flowers. If pollination by bees was to drastically reduce there would be sweeping changes to the composition of plant communities, with non-insected pollinated species gaining an upper hand. A foraging bumblebee might journey as far as four hundred metres from the nest in search for food. We are fortunate that there are still some relatively large areas of flower rich grasslands left in parts of Essex. There are those of the Benfleet Downs in Hadleigh Castle Country Park, for example, home to several scarce species as well as the commoner ones, including the rare shrill carder bee (B. sylvarum). Further west are the marvellous complex of habitats near Basildon that comprise the Essex Wildlife Trust's Langdon Nature Reserve. The reserve also includes a good quantity of herb-rich grassland: excellent foraging habitat for bees.
But such large and accommodating areas of habitat are few and far between in Essex. There are still bee-rich sites dotted around the county, such as along the Flitch Way Country Park (the former Bishops Stortford to Braintree railway line) and the cluster of open land just west of Colchester (e.g. The Lexden Springs EWT nature reserve and the Hilly Fields open space) but further afield bumblebees have to rely on the ribbons of unmanaged grassland associated with grass verges, river banks and seawalls.
What can be done? Improvements in farming and land use will naturally be of benefit to bumblebees, as it would for so many kinds of wildlife. But we can all help their plight. Even a small and not too neat and tidy garden can be stacked full of bee, as well as human friendly plants. A good supply of apple blossom and lungwort, geranium and foxglove, lavender and honeysuckle, among many others (visit the Bumblebee Conservation Trust website for more plants) all help to provide a year round nectar source. And of course, a garden that is good for bees will be good for other wildlife.
As is so often the case with our wildlife, the story of the bumblebee is one tinged with sombre thoughts of hard times for these most endearing of insects. It is a fate though, where each of us can easily make a difference. After all, many of us will see eye to compound eye with them as far as what makes a garden an attractive one. There are not many things better than a garden full of spring and summer colour, complete of course with our furry, four-winged companions.
by Ross Gardner © 2009.
Ross Gardner, an Essex-based naturalist with a degree in Rural Environmental Management, shares his love of British wildlife by helping to develop the Meadowfield Nature Study Centre in Hockley with the owner Jane Mann and educating the many local schoolchildren who visit the centre throughout the year.
To find out more about the centre visit .www.meadowfield.org.uk
Ross is also author of "Essex in the Wild" published by Desert Island books.
References and further reading
Benton, T. (2000) 'The Bumblebees of Essex'. Wimbish: Lopinga Books.
Bumblebee Conservation Trust website, www.bumblebeeconservationtrust.co.uk
Edwards, M. and Jenner, M. (2005) 'Field Guide to the Bumblebees of Great Britain and Ireland'. Ocelli.
Shreeve, J. L. (2007) 'Bee decline threatens our dinner and the countryside' from: www.telegraph.co.uk..