The Solitary Bee Project: One Year On

By Stephanie Maher

About a year ago, I wrote an article for this blog about ‘The Solitary Bee Project’, a citizen science endeavour I had recently launched as part of my PhD research. The primary aim of this project was to compile a dataset of the nest site locations of four solitary bee species and gather some information about where these bees chose to nest. When I was writing the first blog, the project had been running for a couple of months and was starting to gain some momentum. A year on, I can say that not only was significant momentum gained, the project sort of ran away with itself! More than four hundred records were submitted to the website and the enthusiasm of the public for solitary bees was strikingly apparent in the many emails, letters and tweets the project received.

Solitary bees, and particularly their homes, have been rather neglected in the research literature over recent years due to the logistical difficulties associated with doing this kind of work. What this project has shown is that citizen science approaches have the potential to help overcome these barriers. The public have demonstrated that they are keen to protect and learn about solitary bees and they are capable of finding nest sites. By monitoring the submitted records, I was able to identify and visit thirty active nesting sites over the course of the year.

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Stephanie examining an Andrena fulva (Tawny mining bee) site
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Soil samples from some of the nesting locations


From these visits I took a whole host of measurements to try and better understand why solitary bees nest where they do and what makes a good nest site. As one scientist working alone, this partnership with the public was invaluable and allowed me to carry out an analysis I could not have achieved otherwise.

There is still much that we don’t know about solitary bee nest sites, not just in terms of the habitat structure, but a plethora of unanswered questions spring to mind; about nesting behaviour, parasitic species, the relationship between nest sites and foraging resources, how to provide suitable nest sites and much more.

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Huge Colletes hederae (ivy bee) nesting site. Ivy bees were recorded as new to Britain in 2001.
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Colletes hederae (the ivy bee) nesting along side a greenhouse

Now that ‘The Solitary Bee Project’ has ended, I am looking ahead and am optimistic that the future of solitary bee nesting research is bright. There are scientists and citizens around the world who care about these questions and are doing their part to answer them. I am hopeful that soon, whether bees are discussed in conference rooms or coffee shops, the importance of understanding, protecting and providing their homes will be part of the conversation, just as much as their food requirements are. Until then though, I’ve got plenty more work to do!


Stephanie Maher (@SolitaryBeesUK) graduated from Trinity College Dublin in 2011 with a degree in Zoology. She is currently a PhD candidate at Anglia Ruskin University, UK.

Ireland joins the Coalition of the Willing on Pollinators

By Jane Stout

I am delighted that at the Intergovernmental Platform on Biodiversity and Ecosystem Services IPBES 6th plenary in Medellin, Colombia, Ireland officially joined the Coalition of the Willing on Pollinators. This is an international coalition of governments who have the common objective to protect pollinators. It is implemented at country level, with policy and action for pollinator protection.



Ireland is one of the first 20 countries in the world to sign up to the coalition, and this represents a significant national and personal milestone. Getting pollinators up the political agenda in Ireland hasn’t been easy. When Una Fitzpatrick of the National Biodiversity Data Centre and I decided to start developing the All-Ireland Pollinator Plan (AIPP) almost 10 years ago, we did not imagine it would become so successful and influential. At the time, Ireland was suffering the fallout of the economic downfall, and conserving insects was far from most people’s priorities. However, by demonstrating the clear value of pollinators, working with partners from across a wide range of sectors, harnessing public concern for bee decline, lots of enthusiasm, fantastic leadership from Una, and a certain stubbornness, we launched the plan in September 2015.

The response has been overwhelming. More than 80 public and private organisations across the Republic of Ireland and Northern Ireland have agreed to help deliver these objectives so far. The Heritage Council and Bord Bia co-fund a Project Officer at the National Biodiversity Data Centre to help implement the Plan, and together with our partners, we have developed guidelines to provide tailored advice to different sectors – local communities, businesses, gardens, farmland and councils, as well as detailed “How-to” guides (which can all be downloaded for free from So far, 54% of the actions listed in the Plan have been completed and 37% are in train (see year 2 review). This is incredible in just 2 years, and demonstrates the power of commitment and collaboration, especially when financial resources are severely limited.

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The AIPP has achieved national and international recognition – it was hailed as an excellent example of how to engage people with environmental issues at the launch of the Irish National Biodiversity Action Plan in October 2017. The brilliant new infographic cartoon, brain-child of AIPP Project Officer Juanita Brown, has had >60,000 views from around the world already. And the Plan has been commended by various global organisations, with one of the leaders of the Dutch pollinator strategy (launched in January 2018) saying how much she loved the Irish plan at a European COST Action meeting yesterday! Officially joining the Coalition of the Willing is a significant advance in our work to conserve Ireland’s pollinators.

By signing up to the Coalition on 21 March 2018 (along with Bosnia and Herzegovina, Dominican Republic, Mexico and Colombia), Ireland joined the existing 15 partners (Austria, Belgium, Denmark, Ethiopia, Finland, France, Germany, Luxemburg, Peru, Slovenia, Slovakia, Spain, The Netherlands, United Kingdom, Uruguay) and has committed to:

  • taking action to protect pollinators and their habitats by developing and implementing national pollinator strategies, consistent with the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) thematic assessment on pollinators, pollination and food production;
  • sharing experience and lessons learnt in developing and implementing national pollinator strategies, especially knowledge on new approaches, innovations and best practices;
  • reaching out to seek collaboration with a broad spectrum of stakeholders;
  • developing research on pollinator conservation;
  • mutual support and collaboration.


Ireland already meets many of these commitments via the AIPP, which aims to:

  1. Make Ireland pollinator friendly (on farmland, public land & private land)
  2. Raise awareness of pollinators and how to protect them
  3. Manage pollinators appropriately – support beekeepers and growers
  4. Expand our knowledge on pollinators and pollination service
  5. Collect evidence to track change and measure success

But we need a concerted effort by all citizens, as well as public and private bodies, to make a real difference for pollinators. Raising awareness and signing up to the Coalition is only the first step. Making a difference in our policies and actions is required in order to conserve these and other important elements of our natural capital, which provide so much for our society and well-being.

Dr Jane Stout is Professor in Botany at Trinity College Dublin and Deputy Chair of the All-Ireland Pollinator Plan Steering Group.

Mysteries of the humble ribwort plantain


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Figure 1 A Plantago lanceolata flower head, photo by Laura Russo.

Even if you’re not a botanist, you’re probably familiar with the long, thin leaves of ribwort plantain (Plantago lanceolata) poking up through a grassy yard. Growing up in the United States, I knew it well as a potential weapon. If you wrap the stem around the base of the mature seed head, it can be fired as a projectile at the back of your sibling’s head. (The harmless nature of the seed head bouncing off did not deter us from pretending it was a deadly weapon.) Late in the summer, the grass was full of fluffy plantain seed heads: ready ammunition for an eight year old.

The plantain is in the plant family Plantaginaceae, which includes the very familiar foxglove (Digitalis purpurea), which grows in gardens all over Dublin. If you squint, maybe you can see the familial relation between Digitalis and Plantago (or maybe not), but the Plantaginaceae also includes things like speedwell (Veronica sp), which looks pretty different.

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Figure 2 Foxglove in our garden, photo by Laura Russo.
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Figure 3 Speedwell in the grass, photo by Laura Russo

The humble plantain is also at the heart of a massive research network investigating global patterns in population dynamics. Headed by Trinity’s own Yvonne Buckley, this network of researchers around the globe is collecting data on the “environmental and biological drivers of population persistence and extinction”, making Plantago lanceolata like the white lab rat, Drosophila melanogaster, or Arabidopsis thaliana of ecology.

In the States, I was also fond of plantain because of its interactions with bumblebees. Bumblebees, especially the common eastern bumblebee (Bombus impatiens), love to gather pollen from its anthers, but the stem is too thin to hold their weight. It was fun to sit and watch the bee land on the flower and send it plummeting to the ground. Undeterred, they would busily collect pollen from it on the ground and then fly away, allowing the stem to pop back up. In a meadow of flowering plantain, the stems seemed like they were constantly bobbing up and down with bee visits.

After moving to Ireland, I wish I’d done more than idly observe this interaction. Here, pollinator visitation to Plantago lanceolata is rare. And I can quantify that! After spending 12.5 hours (in 150 5-min segments) watching over 600 plantain flowers across the summer, I observed only 14 visitors. That’s just over one visitor per hour of observation. Here in Ireland, those visitors were syrphid flies (Scaeva pyrastri, Melanostoma mellinum, Eupeodes corolla, Episyrphus balteatus, Sphaerophoria sp., Platycheirus angustatus), and two bumblebee species (Bombus pascuorum, Bombus pratorum (aka the tiniest bumblebee)). In the largest dataset on plant-pollinator interactions in Ireland (spanning from 2009-2015 and including more than 200 plant and insect species), the plantain is visited by some of the same syrphid flies as I observed, plus Platycheirus clypeatus, Melanostoma scalare, Helophilus pendulus, Eupeodes luniger, Cheilosia sp, and Bombus lucorum (Fig. 4).

This is a surprisingly high diversity (> 15 visitor species) for a plant that only rarely receives visits! If you were to observe this plant for only a short period of time, you might conclude that it is a specialist, when in fact it is a generalist. It interacts with many pollinator species, just in small numbers.

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Figure 4 Interactions of Plantago lanceolata compiled from Jane Stout’s dataset on plant-insect interactions. The x-axis is the week of the summer, starting at the beginning of May and continuing through August. The y-axis is the number of interactions observed.

The plantain is generally considered to be wind-pollinated, but in Brisbane honeybees have been observed to methodically and deliberately collect pollen from it, and it has been shown to be in their pollen baskets (meaning they were likely taking it back to the hive to provision offspring) (Clifford 1962). I have plenty of data to show that bees collect pollen from species that are putatively wind-pollinated (Russo and Danforth 2017), but the contrast between the visitation of this plant in its native and introduced range is very interesting.

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Figure 5 Distribution of flower visitors over time to Plantago lanceolata…the distribution seems relatively even across the day, including a visitor at five pm.


I have no data for the American plantain and its visitors, but I suspect the visitation rate is higher than in Dublin. Is this related to temperature, as Clifford (1962) suggests? Both the eastern US and Brisbane are much warmer than the UK or Ireland in summer. Or is it something else? Some have suggested that the visitation to the plantain is time dependent (eg Clifford 1962 suggests that because it is warmer earlier in the day in Brisbane, this drives pollinator visitation to the plantain before the wind blows away the pollen), yet the visitation in my study last year (in Ireland) was distributed relatively evenly across the day, with a peak at midday.

Is it possible that the plant has adaptations to attract insect pollinators in its introduced ranges? Is the quality of pollen different? Does visitation by insect pollinators increase seed set in its native range? In its invaded range? I think that this humble garden weed has a lot of fascinating questions for pioneering minds…especially with regard to its pollinators!

Dr Laura Russo is an EU Marie Skłodowska-Curie post-doc Fellow in the Plant-Animal Interactions group at Trinity College Dublin.

The Urban/Wild Divide

Over half of the world’s population now live in cities, and this figure is rapidly increasing. Our progressively more urban world brings the future of wilderness into question. There is a need for a better relationship between urban and wild spaces. Nature and the wild has the potential to become valuable, if not a vital partner in urban environments.

We are a species that construct and delimit ‘wild’ spaces, with our National Parks and wildlife reserves, places where humans are mostly absent. We also built our ‘human’ places like cities, where the wild is assumed to be kept away or non-existent.

Many assume that in an urban environment, with often limited space, there is no room or perhaps need for wilderness. There is this notion that our green spaces must be created, designed and manufactured by humans, with no thought to let nature set its own course.

The famous conversationalist and author, Aldo Leopold, once wrote; ‘No tract of land is too small for the wilderness idea. It can, and perhaps should, flavour the recreational scheme for any woodlot or backyard’.

It is easy to see, however, why people would think that the wild doesn’t belong in urban settings. Urbanisation impacts greatly upon the environment; fragmenting existing habitats, altering the composition of not only the land, but also the hydrology and temperature, whilst creating new pressures such as light, air and noise pollution. All of this results in major impacts to ecosystems and on wildlife.

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Is There Room for Nature Here? (Source; Tony Bock)


Despite the challenges to it, nature and the wild endures in urban environments. Nature utilises the available resources, and over time as it adapts and becomes ‘urbanised’, habitats and species have the ability to flourish.

Insects have become very well adapted to urban living. Due to phenomena such as the heat-island effect, there are actually more insects living in cities than in rural areas. These insects are now a vital component in urban ecosystems.

Despite their importance, insects represent a much berated class in society. Most people want rid of them as they associate insects as being pests, from the creepy crawly in the bathroom to the ants in the back-garden.

Many studies have shown the benefits insect species can in urban areas and on many areas of human life. They perform vital tasks such as; helping break down dead plants and animals to controlling pests.  Bees and other pollinating insects are fine examples of underappreciated species, yet they are common in urban areas and play a vital role in human health, food production and agriculture.

Bees, of which there are over 100 different species in Ireland, help in the pollination of food crops, such as tomatoes, apples, and strawberries. The same food crops which we rely upon for sustenance, rely upon pollination to help maximise fruit production and nutritional quality.

A better connection with our urban wildlife can lead to numerous benefits and provide great values to humans. Although many of the benefits are hard to quantify, they include opportunities for recreation, mental and physical health, and scientific values.

Urban wilderness also acts as a multi-generational living resource. A multi-purpose resource for young and old, capable of acting as a playground, potential area for research and study, even purely as a retreat for people from their busy urban lives. It offers all of these functions, and many more, providing numerous co-benefits at little to no cost.

It is clear that there are both positive and negative interactions between people and urban wildlife. There is a need to move the focus away from the idea of a conflict and towards the benefits  that wildlife can offer. For this to occur more value must be placed on urban wildlife. This can be done through better wildlife education.

Outdoor Classroom (Source; Hagerty Ryan)


Better education prevents misconceptions, ill-informed decision making and has the potential to spark a cultural shift to the view of wildlife as an integral component of urban spaces.

There are other ways that are developing in science and engineering that are helping to reconnect people and our cities with nature and dissolve the imagined wall between the wild and urban spaces.

Concepts such as nature-based solutions hold only have the potential to act as a bridge between nature and urban spaces, but also can become a ‘solution’ to many of our climate-related challenges and social issues.

As defined by the European Commission, ‘nature-based solutions to societal challenges are solutions that are inspired and supported by nature’ (EC, 2015b). This management approach offers the opportunity to bring in more diversity, nature and natural features to our urban landscapes.


Installations such as green belts around cities, and living roofs and walls in buildings, are nature-based solutions that result in not only reconnecting people with nature, they create healthier work/living spaces, reduce the impact of extreme weather events, increase urban biodiversity, offer educational opportunities, the list goes on.

Wild nature is already present in many of our cities, it often just goes unnoticed or is simply just perceived as suspected neglect and is associated with disorder. By establishing acknowledged wild nature in our urban spaces we can create the acceptance and appreciation needed to form nature into an integral part of our urban environments.


Blog by Adam Fowler, Connecting Nature Intern, TCD. Adam is currently studying for an MSc in Global Change: Ecosystem Science and Policy at UCD.    



Urban bees: Health and pollen foraging of honey and bumble bees in relation to habitat structure

This post is a summary of a pilot project, funded by the Eva Crane Trust, which was set up by Campus Buzz initiator, Fergus Chadwick.

Urban beekeeping is becoming ever more popular, due in part to increased societal awareness of bee decline and people wanting to do something positive for bees. Urban landscapes offer a range of resources for bees, including nesting sites for wild bees, and year-round foraging opportunities for both wild and managed bees. Honey can successfully be produced from urban hives, and demand for locally-produced honey is increasing. In Dublin, Republic of Ireland, urban beekeeping has become common among amateur beekeepers and institutions wanting to improve their “green” image. In addition, wild bees (bumblebees and solitary bees) are relatively common across the city. However, relatively little is known about urban bee health, what they forage on, nor how they are affected by urban habitat structure.

We aimed to investigate bee health and pollen foraging in Dublin, and thus selected nine sites across Dublin (Figure 1) where honeybee hives were already established and maintained by local beekeepers, and into each of these sites, we introduced a small, commercially reared Bombus terrestris audax colony (Figure 2). The sites were selected to represent a gradient of urban landscapes, according to the surrounding habitat, in terms of the amount of urban impermeable surface in the surrounding 500m radius and amount of green space/parkland and residential housing in the surrounding 1500m.

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Figure 1: Locations of the nine bee sites in Dublin


Figure 2: Left – Bombus terrestris nest (protected from damage by being placed in a wicker crate, raised from the ground, and protected from rain), Right – Apis mellifera hive on the roof of Trinity College Dublin. (Photos by Fergus Chadwick and Ciara Duffy)

Before installing commercial Bombus colonies in field sites, all were weighed and screened for trypanosome Crithidia and microsporidian Nosema loads. Following installation, colonies were checked once a week and observations of nest activity were made for 60 minutes per colony per week. During this period, workers were captured returning to the nest and pollen sacs removed. One pollen sac per bee was screened for Crithidia and Nosema, and the other analysed for pollen diversity using light microscopy. After five weeks, when colonies had grown to near maturity, but had not produced reproductive individuals, colonies were weighed, brought into the lab, screened for Crithidia and Nosema, and destructively sampled. The difference in initial and final colony weight was recorded as percentage colony growth. Bees were removed from each colony and worker thorax size was measured using digital callipers. Within nests, five cell types were identified: nectar, pollen, larvae, pupae, or nothing and counted.  For each cell type, damage by wax moth larvae, disease or lack of provisioning was noted. The percentage of in-tact “healthy” cells was recorded as an indicator of overall colony health.

During the same period, pollen traps were installed on one honeybee hive per site, and pollen diversity was determined using light microscopy.

We found that there were positive correlations between the percentage urban impermeable surfaces in the surrounding 1500m radius of a site, and the disease loads, worker thorax size, and the proportion of healthy cells in Bombus colonies. There was a negative correlation between percentage urban impermeable surfaces in the surrounding 1500m radius of a site and the proportion of wax moth infested cells. There were positive correlations between the percentage residential housing and disease loads and worker thorax sizes . There were negative correlations between the percentage parkland and disease load and worker thorax size. Pollen analysis has yet to be completed.


This project has provided the first insight into the health of urban bees in relation to urban habitat structure. The amount of impermeable surface, residential housing and greenspace/parkland in the urban landscape all appear to be associated with the health of commercial Bombus terrestris colonies.

In terms of disease loads, we found that built up areas (with more impermeable surfaces and residential housing) were associated with higher disease loads, and that green space and parkland were associated with lower disease loads. Whether this is due to a difference in colony density, disease prevalence, food availability or other factors, is not yet clear.

In terms of worker size, bees were bigger when there were more built up areas, and smaller when there was more parkland.  This is slightly contrary to expectations – we would expect larger bees where there is more green space, and presumably more floral resources and thus pollen availability. However, many urban parks do not offer much in the way of floral resources, being comprised of amenity grasslands and trees which were no longer in flower during the study period.

In terms of the overall colony health, there were more healthy cells when there was a greater extent of impermeable surfaces in the surrounding 1.5km, but colonies more were infested with wax moths when there was more residential housing. This supports previous studies which have shown high levels of wax moth damage in urban residential areas.

Further analyses are required of pollen collected by bees – these findings will help us to understand what urban bees are foraging on, and potentially to inform urban planting decisions.

This study represents a pilot investigation into the relationships between urban landscapes and bees, using just nine colonies of commercially reared Bombus terrestris, and results should be interpreted with caution and not generalised to all wild bees. However, the results of this study will inform further research in this area.



This work was led by Fergus Chadwick, supervised by Prof Jane Stout at Trinity College Dublin. We are grateful to Eoin Dillon, Hallie Tanner and Maximilian Fursman, for help with fieldwork and disease screening, to Dearbhlaith Larkin from Maynooth University for disease screening protocol and training, to Dara Kilmartin for pollen analysis, Archie Murchie for help in securing Bombus colonies, and to all the beekeepers who collaborated and allowed us to sample their hives.

A grant from the Eva Crane Trust supported Fergus Chadwick as a part-time research assistant at Trinity College Dublin from February-August 2017. Fergus developed the project, co-ordinated the site selection, field and lab work, analysed the data and initiated Trinity’s “Campus Buzz” (

We would like to sincerely thank Eva Crane Trust for their generosity in supporting our work.

Prof Jane Stout