Why save one particular species of bee? there are plenty of others after all.
Charlie Heasman; 6th Jan 2021
I was somewhat taken aback to be asked this question by a colleague recently. We all know that globally we are seeing species extinction at an alarming and accelerating rate and that it really might be a good idea to do something about it. We have driven this change; now we must save what we can.
But if this person could ask that question there are probably others who might ask the same. Thus this post.
Regular visitors to this site will know that Sustainable Skerries are involved in formulating a Biodiversity Action Plan (BAP) for the town. They will also know that the primary focus of the Plan is the conservation and protection of pollinators, in line with the National Pollinator Plan run by the National Biodiversity Data Centre.
The poster child of the National Pollinator Plan is a bumblebee. This leads many people to suppose that it is all about bees. It is not, any more than the iconic panda symbol means that the WWF is concerned with saving the panda and nothing else.
Bumblebees are hugely important wild pollinators, but in this case they are more than that. They are also a very useful indicator species. Because they are large and distinctive they are (relatively!) easy to see and count. By recording them over time we can get an idea of which way their numbers are heading, up or down. It can be assumed that other much smaller and harder to see insects will probably also be going in the same direction. And they are all important with their own roles to play.
So let’s look at the Skerries bumblebees for a moment.
Ireland has 21 species; we have seven. That’s actually pretty good going; in many places you’d be hard pressed to find three or four. Of those species all but one belong to the so-called “Big Six”, the six most common species found here. The same applies across the water in the UK, ( although they now often talk about their “Big Seven” because the European Tree Bee has now firmly established itself there – in Ireland we have so far had only a few early and tentative sightings).
The Big Six, and let’s ditch the Latin names for the moment, are:
Buff tailed bumblebee
Red tailed bumblebee
White tailed bumblebee
Common carder bee
The seventh is known as the Large (or Moss) carder bee and is in strong decline across all of its range of Northern Europe, the UK and Ireland. Here in Skerries we have a significant residual population; walk past Loughshinny in one direction, Balbriggan in the other, or even out towards Lusk and you won’t find them. This is the bee I would like to see us save.
Bumblebees, like everything else, can be divided up all sorts of ways. In the case of the bees it can be done by tongue length. The first four of the Big Six listed above can be classified as short tongued, the other two plus the Moss carder are long tongued.
So why’s this important?
Because a long tongued bee feeds on different flowers to short tongued bees.
The Buff tailed bee at the top of the list above is probably our most successful. It is a large bee with a short tongue. This means it can feed on a wide range of open faced flowers. And it does. This no doubt goes a long way to explaining its success; it’s robust, it’s not fussy, and takes every opportunity that comes its way. It’s also the horticulturalist’s bee of choice when it comes to importing artificial nests into glasshouses to pollinate tomatoes and strawberries, which it does far better than any other can, honeybees included. But when it comes to beans it is worse than useless; its tongue is not long enough to reach down into the flower. In fact when hard pressed a Buff tail will bite through the neck of the flower to get at the nectar, thus bypassing the pollination process and ensuring that the flower does not produce a bean.
That’s just one example of why we need species diversity. There are a myriad others but let’s talk about plants for a moment.
Plants have evolved to have flowers for one purpose and one purpose only; and it’s not to make the countryside look pretty. It is to attract pollinators which will facilitate the transfer of pollen from one flower to another, thus fertilising it.
So the more pollinators a flower can attract the better, right? Actually, no.
It is totally useless for, say, clover to be visited by a bee that has been busy all day on apple blossom. The two types of pollen are simply not compatible. It can be in the plant’s best interests to keep certain pollinators out and only let certain species in, the chances of a good pollen match are thus improved. Clover has managed to achieve this by having deep tubed flowers which the Buff tail can’t reach, thus saving its pollen and nectar for a specialist long tongued bee which is more likely to be carrying clover pollen.
Some plants choose to be serviced not by bees but by moths. A white summer flower will likely be one such example. Moths tend to fly at night, so a burst of perfume to guide them in and a luminescent bloom to zero in on does the trick.
There are examples beyond number of these partnerships in nature and we are only beginning to understand a few of them. We simply cannot afford to be blasé and say “oh, that one doesn’t matter, there’s another that looks like it, it can do the same job”. One wouldn’t look at a construction site and remark that an electrician looks a lot like a plumber: “oh, we can afford to lose the electricians, the plumbers can do their job instead”. Construction sites don’t work that way and neither does nature.
I’ll leave this amidst anguished howls from readers by asking, why bother to save the Panda? After all there are plenty of other bear sized bears we can look at. The answer is that the Panda is cute and cuddly and we all love it; me too, don’t worry. But the fact is that if the Panda was to disappear tomorrow the ecological impact would be next to nothing.
Pollinators are another matter; if they go we go.