Are honey bees responsible for the decline in native pollinators and are honey bees responsible for the spread of non native plants.
Are honey bees responsible for the decline in native pollinators and are honey bees responsible for the spread of non native plants.
Q1: Habitat loss, habitat loss, habitat loss, then maybe some other factors ..... plus the fact that some native pollinators are not in decline but are actually spreading .... probably due to climate change. It seems to be the pollinators with exacting habitat requirements that are in trouble.
Q2: Maybe a bit. However the insects pollinating Himalayan balsam round here seem to me to be bumble bees, wasps and honey bees in roughly equal numbers, and that is right beside some of my apiaries. That one plant alone must ensure that populations of all three insect types go into winter in a much healthier state that they used to.
I've even wondered whether the persistent recurrence of AFB at the site near the Isla (mentioned by Murray and DR in another thread) is helped by the sea of HB there helping swarms occupying old sites get through the winter. That is another reason for a high level of care in swarm prevention - if you let a certain proportion go as a matter of routine then they might come back to bite you next season when they spread disease back into your apiaries.
I would say that Beekeepers tendencies to move bees to nectar sources like balsam is certainly contributory.
I've even known of a Beekeeper who moved the balsam to him, he would t be the only one so its surely a factor.
As usual for most (all?) species, the greatest competition comes from members of the same species or very closely related species. Native honeybees have been in decline ever since imports began and they are surely part of our native pollinating fauna. Other moths, bumbles, masonry / carpenter, hover flies what have you occupy different niches and no study I've read indicates honeybees have adversely affected their populations.
As troublemaker Gav points out, habitat loss is number one, two and three on why some species are in decline.
Interesting but Habit loss on its own may not cover everything isolation, and fragmentation, inbreeding non-native species and diseases; pollution, are all contributing factors also, But lets look at Honey bees they are not native to either America or New zealand so it would be interesting to know of their impact on native species there. If the Great yellow bumblebee Bombus distinguendus was discovered off an Island in Scotland would it be a good idea to introduce hives there as both would be competing for the same flora.
In Australia there is some weak evidence that honeybees outcompete native pollinators for floral resources but mainly tend to favour the non-native (mainly European) plants. I think Dave Goulson has been involved in some research on bumblebees in the UK where the suggestion was honeybees might be exploiting floral resource to the detriment of the bumbles on heather moors.
Also this by Goulson(2003): Annu. Rev. Ecol. Evol. Syst. 2003. 34:1–26 doi: 10.1146/annurev.ecolsys.34.011802.132355
Then there is this more recent paper, although a clue is in the abstract "in simplified landscapes where flower-rich habitats have been lost".
http://www.sciencedirect.com/science...39179116300378
Maybe everyone knows this but Himalayan balsalm is an invasive non-native plant pest species. It occurs mainly along river and stream banks. Since it shades out most other native species in these habitats (ie, reduces plant species diversity), surely beekeepers should not be encouraged to contribute to its long-term spread for (dubious?) short-term nectar supplies?
Yeah its very invasive. Here in Germany they are rife along woodland boundries. I think they fire their seeds up to 5m so spread merrily without much help. The upside for beeks is they provide an excellent late crop for that the bees can overwinter on very well. Some years you do not need any winter feed at all. So I can see a beeks motivation for leaving / planting them.
The environmental protection agency habitually has a purge to get rid of them. Their seeds are very tasty by the way - taste nutty.
If you spray a field the overspray just drifts over the field boundaries
So planting a strip of grass and nectar plants along a field boundary is not ideal
Well that's how it seems to me
After the neonic ban the crops grown round here are more diverse
It was just rape , grain, potatoes now already there are far more crops being grown
Plus there are more cows and sheep showing up in fields
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