Andrew Brown: Remarkable journeys of centimetre long species

Picture by Tree Bee Society / SWNS.
Picture by Tree Bee Society / SWNS.

One of the great pleasures of bee keeping is standing by the side of a hive watching the girls fly in and out and trying to figure out what they have been doing and where they have been.

When everything is going well there is a regular stream of bees arriving and departing and a good proportion of those coming back have brightly coloured pollen stuffed into little pouches on their back legs.

The colour of that pollen can tell you quite a bit about what they’ve been up to. Early in the year mine were bringing back lots of bright yellow pollen from sources such as dandelions. Then they started to come back with bright orange or with purple pollen. If I’m lucky they will soon find the local heather and their pollen baskets will contain protein that is greyer in colour.

What they return with depends on how far they are flying and what they happen to discover on their flights.

In the wild a honeybee most often flies 0.4 miles from the hive to the flower that provides them with the nectar and the pollen that they need. Yet they average almost a mile and have been measured flying as far as 6.8 miles with a return journey of equal length.

That is a truly incredible achievement for an animal that is approximately a centimetre long. In order to discover a good food source that far away the bees are scouting our phenomenal quantities of territory.

If you draw a circle around a wild hive that is large enough to enclose 95 per cent of the colony’s food sources then it has been found to enclose an area of 43 square miles. Even with a colony that contains 10,000 foraging bees, searching such a large area is an incredible undertaking, according to beekeeping professor Thomas Seeley.

The way they achieve adjustments to their preferred routes is beautifully simple. The bees inside the hive simply respond to whatever is happening when each bee returns from its trip. If she comes back fully loaded with excellent quality pollen and nectar then she offloads what she has collected and does a little dance to tell the other foraging bees how good the site was.

If bees start coming back empty handed or with little then they don’t recruit any new bees to go back to the place where they wasted so much energy.

Alternatively, if the hive is short of honey then bees returning with nectar will be most enthusiastically received, and their route will be willingly followed. If a bee comes back with something that is normally very useful such as nectar but at a time when the hive is struggling to keep cool and needs water then few will copy the nectar carrier.

Sometimes it is hard to avoid thinking that humanity might be a lot better off if we were as remotely as good at quickly adjusting to changes in what society needs.

Speedy

Prof Seeley has shown that bees find food sources with remarkable speed. Hide food sources at random within a three-mile circumference in forest with no flowering plants and the bees can be expected to find every single one of the hidden resources within a fortnight.

Change the richness of the food available and the bees will change the number of foragers they send out within two hours.