Before RSPB bought North Plain and Rogersceugh farms much of the land was monoculture grass which had received fertiliser and had few meadow flowers. Over the years as the nutrient levels have fallen more wild flowers have appeared.
Six years ago, on a route from the salt marsh to the top of the drumlin at Rogersceugh, we began to record the different species of bumblebees and note which flowers they were visiting for pollen and nectar. The route we adopted covers all the main habitats on the reserve including meadows, woodland, hedgerows, salt marsh, raised lowland mire (peat bog) and arable fields. We began with very little knowledge and had to learn identities as we went along. This was not quite as difficult as it may sound as there are less than thirty species in Britain and of these just under half are likely to occur.
Queens which have hibernated over winter usually appear in late March or early April and are the only bees to have survived from the previous year having mated in late summer or autumn. They need a good supply of pollen or nectar immediately and without this they are doomed. Most often we have found them first on the catkins of willow trees. Queens then build nests, often in old mouse or vole nests or for some species under clumps of grasses or other dense plants. A few weeks later workers can be seen. They are much more numerous (up to 200 per nest depending on species) and generally noticeably smaller than the Queens. As the summer progresses and into early autumn new queens and males (drones) appear.
We have been doing the surveys monthly from April to October for the past six years. So far we have found 12 species of which 3 were cuckoo bees whose queens use the nest and workers of another species. Each year there has been an increase in the total number of bees found, except in 2013 when the number fell back slightly. Last year and this year the increase has been more dramatic; in both July and August this year on single days we counted nearly 250 bumblebees, which was more than we had found throughout the whole of the first year. This year there have also been huge numbers in the arable fields which we did not attempt to count. These fields are planted to provide seed for birds in winter but in the flowering season they are brilliant for bees and many other insects.
Over the six years the number of plant species on which we have found bees has increased. In the first years some of the grassy meadows had practically no flowering plants but over last two or three years more and more have been found, especially vetches, trefoils and clovers but smaller numbers of other plants as well. In addition large numbers of wild flowers have been planted particularly in the Discovery field. This has corresponded with an increase in the bees found there. Between 2010 and 2013 we found bumblebees on 47 species of plant; by the end of 2015 this had risen to 70 plants and we suspect that when this year’s figures are analysed will have risen a bit more.
Neil & Marjorie Hutchin
Species of bumblebees found at Campfield Marsh RSPB Reserve
Bombus lapidarius
Not as common as elsewhere but more this year.
Bombus monticola
Only odd ones seen. Common on the fells.
Bombus pascuorum
The most numerous of all here.
Bombus hortorum
Common
Bombus jonellus
Not many found but probably more common
than it seems as it is somewhat elusive and harder to identify.
Bombus terrestris
Very common
Bombus lucorum
Very common but workers indistinguishable from buff-tailed.
Further species of bumblebees found at Campfield RSPB Reserve.
Bombus hypnorum (Tree) and pratorum (Early).
In addition to the above species of true bumble bee, three species of cuckoo bee have been found.
Bombus sylvestris (forest cuckoo bee), bohemicus (gypsy cuckoo bee), and campestris (field cuckoo bee).
Bombus bohemicus