Tag Archives: Bees

Impacts of the introduced European honey bee on Australian bee-flower networks – a new study just published

As I mentioned in my previous post, it’s currently Invasive Species Week in the UK. Non-native species which have negative environmental impacts and disrupt infrastructure are a global phenomenon, of course, and almost all regions of the world have been impacted by species that originated elsewhere. One alien species that is of growing concern in Australia is the western honey bee Apis mellifera. We often think of bees as being relatively benign organisms, but a number of species have been introduced around the world and may compete with native species for nectar and pollen, and nesting sites.

In the second paper from my collaboration with Dr Kit Prendergast, we’ve assessed how introduced honey bees change the structure of bee-flower visitation networks in Australian urban habitats. The main finding is that when honey bees are common, they dominate these networks in ways that indicate significant competition with native bee species. You can get a sense of that from the figure above: the honey bees are in red, native bees in yellow, native plants in light green, and non-native plants in dark green. The length of the bars is proportional to the abundance of these plants and bees.

To say that honey bees ‘dominate’ these networks is an understatement: not only are they vastly more abundant than the other bees, but they visit almost all of the different types of flowers in the network, regardless of whether they are native or introduced.

Although the honey bee bullshit machine often claims that western honey bees are dying out, the exact opposite is true: across the world, managed Apis mellifera numbers are higher than ever, as you can see from the following chart based on figures from the United Nations Food and Agriculture Organization (UN-FAO):

Whilst the growth in honey bee numbers is a good thing for honey producers, bee farmers, and small-scale subsistence farmers, there are environmental consequences to the increase in hives, as we have shown.

If anyone wants a PDF of the paper, please use the Contact form. The full reference for the study and the abstract is:

Prendergast, K.S. & Ollerton, J. (2021) Impacts of the introduced European honeybee on Australian bee-flower network properties in urban bushland remnants and residential gardens. Austral Ecology (in press) https://doi.org/10.1111/aec.13040

Abstract:

The European honeybee Apis mellifera is a highly successful, abundant species and has been introduced into habitats across the globe. As a supergeneralist species, the European honeybee has the potential to disrupt pollination networks, especially in Australia, whose flora and fauna have co-evolved for millions of years. The role of honeybees in pollination networks in Australia has been little explored and has never been characterised in urban areas, which may favour this exotic species due to the proliferation of similarly exotic plant species which this hyper-generalist can utilise, unlike many native bee taxa. Here, we use a bipartite network approach to compare the roles, in terms of species-level properties, of honeybees with native bee taxa in bee-flower (‘pollination’) networks in an urbanised biodiversity hotspot. We also assessed whether the abundance of honeybees influences overall network structure. Pollination networks were created from surveys across seven residential gardens and seven urban native vegetation remnants conducted monthly during the spring-summer period over two years. There were consistent differences in species-level properties between bee taxa, with honeybees often differing from all other native bees. Honeybees had significant impacts on network properties, being associated with higher nestedness, extinction slopes of plants, functional complementarity and niche overlap (year two), as well as lower weighted connectance and generalisation. These associations all are indicative that competition is occurring between the introduced honeybee and the native bee taxa in bee-flower networks. In conclusion, the introduced honeybee occupies a dominant, distinct position in bee-flower networks in urban habitats in the southwest Western Australian biodiversity hotspot

For World Bee Day 2021: an update of the coffee-bee visits figure from my book

Today is World Bee Day 2021! To celebrate it, here’s an update of a figure that appears in my book Pollinators & Pollination: Nature and Society. It’s reminder of just how important bees are as the main pollinators of coffee, one of the world’s major crops. The new figure adds another two years of data and also improves the accuracy of some of the statistics for the previous decade. The coffee production data are from the International Coffee Organization.

Bottom line is that the global coffee production in 2019/20 was the result of 24 TRILLION flower visits by bees! That’s down a little from the previous year, but it’s still a LOT of visits by a HELL of a lot bees!

If you want to know more about how this was calculated and what it means for both coffee production and bee conservation, I discuss it with Dr Kirsten Traynor in this recent podcast for the magazine 2 Million Blossoms.

Happy World Bee Day everyone!

New article just published: ‘Pollinators and pollination: myths, misunderstandings and much more to discover’

My first (and hopefully not my last) article for the magazine British Wildlife has just appeared in the April issue. Entitled ‘Pollinators and pollination: myths, misunderstandings and much more to discover’ you can get a preview here: https://www.britishwildlife.com/article/volume-32-number-5-page-316-323

The article focuses on some of the myths and misunderstandings that I dealt with in my book Pollinators & Pollination: Nature and Society. It also points out that, even in a place like Britain with a long tradition of natural history study, there’s still much for the patient observer to discover. If you’re interested in a PDF, drop me a line via the Contact page.

Pollinators are allies in the fight against climate change: a new commentary just published in New Scientist

Over the past few months I’ve been thinking a lot about the relationship between the “Climate Emergency” (CE) and the “Ecological Emergency” (EE), and how they overlap considerably in terms of causes and solutions, but that the priorities of the CE often trump those of the EE. One of the outcomes of this has been a commentary that’s been published in New Scientist this week. It’s free to access – here’s the link:

https://www.newscientist.com/article/mg24933260-100-pollinators-are-our-secret-weapon-in-the-fight-against-global-warming/

It’s extracted from a much longer article that discusses the role of pollinators in relation to climate change. Hopefully that will be published in the not too distant future.

The other thing that’s happened this week is that, in my role as Visiting Professor of Biodiversity at the University of Northampton, I was asked to take part in a webinar that’s one of a series being produced in support of the Levelling Up Goals. The LUGs, modelled on the UN’s Sustainable Development Goals (SDGs) have cross-party support in Parliament and aim to bring economic prosperity to those parts of the country that have lagged behind in recent decades. The “Green Economy” is seen as central to this.

The webinar was recorded and you can view it here: https://www.fit-for-purpose.org/engage/how-to-level-up-harness-the-energy-transition

It was interesting and I learned quite a bit, for example about how the government is investing the state pension pot in sustainable energy projects. The format of the webinar, however, with the chair asking individuals a question and each of us responding, was a little frustrating as there was no real opportunity to counter statements being made, particularly by the MP for Hexham.

Yesterday Karin and I had out first COVID-19 vaccination; today we both feel a little under the weather, but it will pass. It’s certainly better than the alternative!

Finally, a physical copy of my book!

Yesterday I was delighted to finally receive an advance copy of my book Pollinators & Pollination: Nature and Society! It’s been over three years in the writing and production, much longer than I had anticipated. But, as I describe in its pages, the book is the culmination of >50 years of experience, study and research. So perhaps three years isn’t so bad…

If you’re interested in buying a copy you can order it direct from Pelagic Publishing and from most of the large online booksellers. Let me know what you think.

Seminar: ecology and botanical history of the Himalayas – online on 11th September

Dwyer Lecture Flyer 2020

This year’s Missouri Botanical Garden/St Louis University John Dwyer Public Lecture in Biology will be given by Alan Moss who researches Himalayan bumblebees and their interactions with flowers.  The lecture is being live-streamed on YouTube – details are in the flyer above.

Get a 30% discount if you pre-order my new book Pollinators & Pollination: Nature and Society

PollinatorsandPollination-frontcover

In the next few months my new book Pollinators & Pollination: Nature and Society will be published.  As you can imagine, I’m very excited! The book is currently available to pre-order: you can find full details here at the Pelagic Publishing website.  If you do pre-order it you can claim a 30% discount by using the pre-publication offer code POLLINATOR.

As with my blog, the book is aimed at a very broad audience including the interested public, gardeners, conservationists, and scientists working in the various sub-fields of pollinator and pollination research. The chapter titles are as follows:

Preface and Acknowledgements
1. The importance of pollinators and pollination
2. More than just bees: the diversity of pollinators
3. To be a flower
4. Fidelity and promiscuity in Darwin’s entangled bank
5. The evolution of pollination strategies
6. A matter of time: from daily cycles to climate change
7. Agricultural perspectives
8. Urban environments
9. The significance of gardens
10. Shifting fates of pollinators
11. New bees on the block
12. Managing, restoring and connecting habitats
13. The politics of pollination
14. Studying pollinators and pollination
References
Index

 

 

For World Bee Day – an extract from my forthcoming book – UPDATED

Image

UPDATE: turns out the figure I cited for number of bee species is out of date so I’ve corrected it below. Thanks to John Ascher for pointing this out.

Publication of my book Pollinators & Pollination: Nature and Society by Pelagic Publishing has been pushed back until the end of this year or early in 2021. The current pandemic has created problems for the printing and distribution sectors, as it has for so many industries. Therefore, to celebrate World Bee Day, here’s a preview of the bee section from Chapter 2 which is entitled (ironically enough) “More than just bees – the diversity of pollinators”.

2.3 Bees, wasps and sawflies (Hymenoptera)

The bees and their relatives rank only third in terms of overall pollinator diversity.  Within this taxonomic Order, bees are not especially species rich (17,000 or so described species, perhaps 20,000 in total) – over 20,400 (see: https://www.catalogueoflife.org/col/details/database/id/67) compared with the other 50,000 social and solitary wasps, sawflies, and so forth. But what they lack in diversity the bees make up for in importance as pollinators of both wild and agricultural plants, and in their cultural significance.  The general notion of what a bee is, and how it behaves, looks to the honeybee (Apis mellifera) as a model: social, with a hierarchy, a queen, and a large nest (termed a hive for colonies in captivity).  In fact, this view of bee-ness, though long embedded within our psyche, is far removed from the biology of the average bee: most of them have no social structure at all, and a fair proportion of those are parasitic.  In Britain we have about 270 species of bees, give or take (Falk 2015) though there have been extinctions and additions to this fauna (see Chapters 10 and 11).  These species provide a reasonable sample of the different lifestyles adopted by bees globally.  They can be divided into four broad groups.

Honeybees include several highly social species and subspecies of Apis, of which the ubiquitous western honeybee (A. mellifera) is the most familiar.  Most colonies are found in managed hives, though persistent feral colonies can be found in hollow trees, wall cavities, and other suitable spaces.  They are widely introduced into parts of the world where they are not native (e.g. the Americas, Australia, New Zealand) and there is some debate as to whether they are truly native to Britain and northern Europe, with supporting evidence and arguments on both sides.  Colonies can be enormous and contain thousands of individuals, mostly female workers, with a single queen.  Unmated queens and males (drones) are produced by the colony later in the season.

Bumblebees (Bombus spp.) are typically also social, though their nests are much smaller (tens to hundreds of individuals).  Depending upon the species these nests can be in long grass, rodent holes, or cavities in buildings and trees.  Twenty-seven of the more than 250 species have been recorded in the UK, but six of these are not strictly social; they are parasitic and belong to the subgenus Psithyrus which will be described below.

The so-called solitary bees are by far the largest group in Britain (about 170 species) and worldwide (more than 90% of all species).  In the UK they belong to 15 genera, including Andrena, Anthophora, Osmia, Megachile, etc.  The females of most of these bees, once they have mated, construct nests that they alone provision with pollen for their developing young.  Nesting sites can be genus- or species-specific, and include soil, cavities in stone or wood, and snail shells.  Some species are not strictly solitary at all and may produce colonies with varying levels of social structure, though without a queen or a strict caste system; we term them “primitively eusocial”.  In fact sociality has evolved and been lost numerous times in the bees and in the rest of the Hymenoptera (Danforth 2002, Hughes et al. 2008, Danforth et al. 2019).  It’s also been lost in some groups that have reverted back to a solitary lifestyle, and even within a single genus it can vary; for example in the carpenter bee genus Ceratina (Apidae: Xylocopinae) tropical species are more often social than temperate species (Groom & Rehan 2018).

The final group is termed the cuckoo bees and, like their avian namesake, they parasitise the nests of both social and solitary bees (though never, interestingly, honeybees).  There are about 70 species in 7 genera, including the bumblebee subgenus, Psithyrus.  Other genera include Melecta, Nomada and Sphecodes.  In some cases the parasitic species are closely related evolutionarily to their hosts and may resemble them, for example some Psithyrus species.  In other cases they may be only distantly related and in fact look more like wasps, e.g. Nomada species.  Some genera of cuckoo bees are restricted to parasitising only a single genus of bees, others are parasites of a range of genera (Figure 2.4).

Although we often think of bees, overall, as being the most important pollinators, in fact species vary hugely in their importance.  Pollinating ability depends upon factors such as abundance, hairiness, behaviour, body size, and visitation rate to flowers (Figure 2.1).  Size is especially important for three reasons.  First of all, larger animals can pick up more pollen on their bodies, all other things being equal.  Secondly, in order to bridge the gap between picking up pollen and depositing it, flower visitors must be at least as large as the distance between anthers and stigma, unless they visit the stigma for other reasons.  Finally, larger bee species tend to forage over longer distances on average (Greenleaf et al. 2007) thus increasing the movement of pollen between plants.  However, most of the world’s bees are relatively small as we can see from the analysis of British bees in Figure 2.5.  Many species have a maximum forewing length of only 4 or 5 mm, and the majority of species are smaller than honeybees.  Remember also that these are maximum sizes measured from a sample; individual bees can vary a lot within populations and even (in the case of Bombus spp.) within nests (Goulson et al. 2002).  So the assumption that all bees are good pollinators needs to be tempered by an acknowledgement that some are much better than others.    


Figure 2.5: The sizes of British bees. Forewing length is a good measure of overall body size and the data are maximum lengths recorded for species, except for the social bumblebees and honeybee I have used maximum size of workers (queens are often much larger). The blue line indicates the honeybee (Apis mellifera). The biggest bee in this data set is the Violet Carpenter Bee (Xylocopa violacea) which, whilst not generally considered a native species (yet), has bred in Britain in the past. Data taken from Falk (2015).

A pollinator to watch out for in your gardens: the Red-girdled Mining Bee – UPDATED

Last week, during one of my lockdown garden pollinator surveys, I spotted a bee visiting Germander Speedwell (Veronica chamaedrys) in the garden that I didn’t recognise. It initially confused me as it looked superficially like a Blood Bee in the genus Sphecodes. However the bee was clearly collecting pollen, which Sphecodes spp., being cleptoparasites, don’t do. A quick check in Steven Falk’s Field Guide to the Bees of Great Britain and Ireland and a look at Steven’s Flickr site, suggested that it was almost certainly the Red-girdled Mining Bee (Andrena labiata), which is frequently associated with Germander Speedwell.

I posted this video on Twitter and Steven kindly confirmed my identification:

The Red-girdled Mining Bee is considered “Nationally Scarce” and it has a scattered and southerly distribution, as you can see from the map above, which is from the National Biodiversity Network Atlas account for the species. It’s only recorded from about half a dozen sites in Northamptonshire according to Ryan Clark, the County Bee Recorder. However Steven tells me that it’s being seen more and more frequently in gardens, and indeed just the other day Sarah Arnold, who is also carrying out surveys, emailed me to say that she had spotted it in her garden in Kent.

So this is a bee that’s definitely one to look out for, especially if you have Germander Speedwell growing.

UPDATE: I should of course have also given a link to the BWARS account for this species, and mentioned that confirmed or suspected observations can be uploaded to iRecord.

Landscapes for pollinators: please take the survey!

BB on margin

One of the research projects and collaborations that I’m involved with is a BBSRC-funded project entitled “Modelling landscapes for resilient pollination services in the UK” with colleagues from the University of Reading, the University of Huddersfield, and the Natural Capital Solutions consultancy.  As part of that project we are surveying opinions on what people in the UK value as landscapes and how these landscapes contribute to supporting biodiversity.

If you are based in the UK and are interested in taking part in this short survey, please read the following text and click on the link to take the survey: 

Bees and other insect pollinators are major contributors to UK agriculture. Despite their importance for crop production, pollinator populations are threatened by many modern land management and agricultural practices. This raises questions about how secure this service may be to future changes: will we have enough pollinators where we need them? Will populations be able to withstand changes to the way we manage land? What might be the costs to us, both financially and socially, if we get it wrong?

Our research aims to address this knowledge gap. Our team of ecologist, economists and social scientists are working together to model the ecological, economic and ‘human’ costs of different land management methods.

As part of this we have designed a short online survey to capture the ways that people value and use the countryside, what features they prefer and why.

The survey takes less than 10 minutes and asks you to rate a series of images and say what you think about the landscapes that are illustrated.  It can be found here:

http://hud.ac/landscapes

For more information about the project visit:

http://www.reading.ac.uk/caer/RP/RP_index.html