Bumblebees take up residence

While bumblebees have always been regular visitors to my town centre garden, this year is the first that I have actually witnessed a queen bumblebee take up residence. An abandoned small mammal hole in my main flowerbed, most likely that used by a colony of wood mice last summer, has been taken over by a nest of buff-tailed bumblebees. Throughout the day, a growing procession of worker bumblebees enter and leave the tiny hole in the woodchip mulch, near the base of one of my aquilegias. I am amazed by their industry.

The buff-tailed bumblebee is one of our most common and widespread bumblebee species, occurring right across England and Wales, and now expanding its range within Scotland. If you see a large bumblebee in spring, with two yellow bands on a black background and a buff or off-white tail, then the chances are that you have seen this species. The workers that are on the wing now are smaller than their queen, similar in colour and pattern, though with the tail white rather than buff. If you look closely then you may see that the white tail has a thin line of buff between it and the black of the abdomen.

The nest itself will be placed at the bottom of the long tunnel that drops down through the soil, and will consist of an untidy dark-brown comb, more than likely covered by a waxy cap. The nest will be where the first generation of workers would have been reared by the queen before they, in turn, go on to rear subsequent broods. Also present will be the stores of pollen, large quantities of which are stored in tall cylinders of wax. Right now, the colony is probably still rather small; buff-tails are notoriously slow in getting their colonies going. However, numbers will keep growing and, at its peak, the colony may number several hundred workers. The outcome of all this industry is not simply the workers, since these are means to an end. Later in the summer the first males and daughter queens will be produced. It is these that will set forth and continue the bumblebee line. If things go well, the colony may complete two cycles in a single season.

The worker bumblebees can be seen foraging around the garden, visiting many of the flowers that I have planted in the hope of providing suitable nectaring opportunities. Buff-tails are slightly shorter tongued than certain other bumblebee species and so are unable to gain access to every flower. Interestingly, they sometimes overcome this problem by biting through the flower tube (known as the corolla) to steal nectar. It is wonderful to see such resourceful creatures doing so well.