Monday 17 October 2016

Non-native invasive species. Friends or foe?

I've been thinking a great deal over the last few years about 'non-native invasive species' and wondering whether some might actually be more 'friend' than 'foe'.

Species like the Asian hornet are clearly a great threat to diversity because if they establish a foothold in the UK, they have the potential to wreak havoc on our bee population which, as well as being a concern in its own right, will of course have a knock on effect on the plants our native bees currently pollinate and the eco systems these plants support.

But what about other recent arrivals? What about Ivy bees and Tree bumblebees? Unlike the Asian hornet these species are not 'predators' nor have they arrived via human agency. But could they be competing with our existing population of bees (and other insects) for foraging and habitat? Do we know yet if this is the case? Does it matter? If not, why not? Maybe these and other new species arriving from Northern Europe will prove better equipped to deal with an ever changing landscape and climate that our existing bee species might struggle with in the future. 

And then there's Himalayan balsam. This plant is vilified by most, but having established itself is now providing much needed late season nectar and pollen for our native pollinators. Maybe, in time, it will turn out to have other benefits that we don't yet know about? Perhaps it will be better able to cope with climate change, rising temperatures and flooding than some of our native plants? And what would be the consequences to the eco systems it now helps to support if we were to pull it all up and completely eliminate it? I don't know the answers to these questions, but can't help wondering.

Food for thought.... and as an aside, I think we would do well to remember that we, the human race, cause more damage to biodiversity than all the invasive plants put together. When human beings talk about 'invasive species', the expression 'pots and kettles' springs to mind.

Against this backdrop of our (innate?) fear of non native invasive species taking over our countryside, is the current trend for more and more people to keep honeybees in towns and cities. I find myself unable to reconcile the fear of the former with the acceptance and encouragement of the latter.  Do those who set up new hives plant more pollen and nectar rich plants to help sustain their increasing honeybee populations? If not, and if natural resources are limited, do these hives then need to be routinely fed on sugar water over winter? And how do native bumblebees, solitary bees and other pollinators cope when tens of thousands of extra (managed) honeybees are suddenly introduced to an area where the existing floral resources are already depleted?

I ask these last questions (about bees) because where I live in Shaftesbury, North Dorset, I have seen a huge increase in the number of honeybee hive being kept by local beekeepers over the last couple of years. Where these colonies are at their most dense I am now noticing that bumblebees are conspicuous by their absence on sedum and other plants popular with the honeybees, whereas further out of Shaftesbury, in surrounding villages where there are not so many beehives, the sedum, at least, is covered in bumblebees and butterflies in the autumn. 

So many questions, but not many answers.  On balance, I have to say I am no longer sure what to think, per se, about non-native invasive species.... especially when I am noticing, first hand, our native wild bees being outcompeted on some flowering plants by the increase in popularity for keeping honeybees.

If you are interested in exploring these questions further, you might like to read The New Wild by Fred Pearce. A very thought provoking book!

Also, check out this post on Biff Vernon's Blogspot.

With many thanks to twitter friend @dolly_and_dj for allowing me to use her beautiful photograph x

P.S. I should add (in case it appears that I am picking on beekeepers) that my partner and I have a few hives ourselves and are fortunate enough to be able to keep our bees out of town in an area where there are very few other beekeepers.

Sunday 9 October 2016

Have you seen this bee?!

Ivy bee Colletes hederae
It's Sunday 9th October. The sky is blue, the sun is shining and the Ivy is in full flower.

Common Ivy Hedera helix provides an abundance of autumn pollen and nectar for bees and other pollinators. So sweet and powerful is its scent that you can usually locate flowering ivy by smell alone, but if your sense of smell fails you, just close your eyes and listen.... for, on a day like this, it is literally alive with the buzzing and humming of insects.

If you find a patch of flowering ivy, perhaps you might consider taking a little time out to stop and look more closely at the myriad insect species feasting upon its rewards. On a warm day like this you are likely to see honeybees, bumblebees, butterflies, wasps, flies, hoverflies AND - depending on where in the country you live - Ivy bees

Ivy bees Colletes hederae are relatively new to the UK. They were first recorded in Dorset in the early 2000's, but have since been recorded in other southern counties. They are now expanding their range north and have, this week, been recorded for the first time in Heysham, Lancashire.

Ivy bees are 'solitary bees'. They do not live in social colonies like honey bees or bumblebees, but nest alongside each other in large aggregations, usually in banks of compacted sandy soil.

BWARS (Bees, Wasps & Ants recording Society) are mapping and monitoring the spread of this bee, but need our help to do this. All they ask, is that you take photos of any Ivy bees you see and submit them on line to the BWARS mapping project or on iRecord . Either will do.

I shall add a couple of photos below of other insects that people often mistake for Ivy bees, but if you're still not sure, upload your photo to iRecord and someone in the know will help you identify it.

iRecord is SO worth signing up to anyway, because it is a wonderful way to manage all your wildlife sightings.

So, have an adventure! Make some sandwiches, dig out a flask, get your walking boots on, stick your camera in your bag and become a citizen scientist!  Of course you may have ivy growing and flowering in your back garden, in which case I suggest you grab a cup of tea and a deck chair instead of your walking boots and rucksack. Either way, today might be the day you find and identify your first Ivy.... and if you live up North you might just be the first to record an Ivy bee in your neck of the woods.

Here's the link for iRecord again - iRecord

A fact sheet about Ivy bees - Fact sheet

Submit sightings here - BWARS mapping project

And finally, some photographs of insects that are NOT Ivy bees.....

N.B You can easily tell the wasps apart because they are predominantly yellow, but hoverflies can sometimes be quite confusing. The hoverfly in the photo below behaves for all the world as though it were a bee, but check out its large 'fly eyes' and short antennae and you will see they are very different to those of a bee. Bees have more oval shaped eyes and long antennae.

If it is carrying pollen on its legs then it is definitely either a honeybee, a bumblebee or a solitary bee. Other insects do not carry pollen. However, if it's not carrying pollen it could still be a bee because bees also forage for nectar.

Honey bee Apis mellifera
Bumblebee Bombus terrestris photo by Gordon England 

Hoverfly Eristalis pertinax

Common wasp Vespula vulgaris

Sunday 2 October 2016

Asian Hornets and Human Beings: what do they have in common?

Asian hornet Vespa velutina (Image from Wildlife Trusts)
I've been thinking a great deal about the Asian hornet, Vespa velutina, which could wreak havoc on honeybees and native wild bees in the UK if left unchecked.

For those who are unaware, an Asian hornet nest was found recently near Tetbury, Gloucestershire. It has now been destroyed; hopefully before any new queens had a chance to emerge and disperse.

The discovery of this non-native invasive species has understandably caused great alarm and concern- especially amongst the beekeeping community- and the response from the authorities has been to act swiftly to try and prevent this species from colonising.

None of the responses in the mainstream media or social media 
to the potential invasion of the Asian hornet surprise me. Indeed most have been entirely appropriate. However they have left me wondering what it is in human beings that make us (seemingly) oblivious to our own impact on the natural world; or at least unwilling to do what is needed to check that impact.  

The damage to native eco systems caused by non-native invasive species - no matter how serious and how huge - pales into insignificance compared with the damage we, as a race, cause to the planet as a whole.
If there is a higher intelligence out there, watching our progress as we explore space and other planets, I should think they are probably on red alert by now. I can just imagine the headlines if we ever managed to colonise one of these planets.....
"Alert! Human colony found on planet xMy$7z! Individuals and groups of this (highly intelligent and social) species have been spotted building structures on the mountains above &^^^%. Humans vary in temperament. Some forms are mild, respectful, thoughtful and gentle; wishing only to share our resources and work alongside local native inhabitants for the greater good of the whole. These forms may not pose a threat and could even contribute and add ecological value to the existing community of flora and fauna. Other forms however can be extremely aggressive, demanding and controlling, even when unprovoked.

Collectively this species poses one of the biggest threats in the solar system to an unprotected planet. Their voraciousness knows no bounds. They have already colonised and destroyed Planet Earth. Approach with care and please notify the intergalactic authorities if you see one of these individuals or groups in your zone. Etc, etc....."

An interesting and balanced article about the Asian hornet from a beekeeper in France who has first hand experience of this species - Asian Hornet

Useful identification guide here - Wildlife Trusts: Asian hornet