From February 2023, I will be taking on the role of Biodiversity Officer for the Gasworks Dock Partnership charity based at Cody Dock on the tidal stretch of the River Lea in east London. I will be co-ordinating volunteer opportunities for surveying and monitoring habitats and wildlife of the local area and delivering related training to our network of community scientists.
Not exclusively focused on invertebrates (though you can be guaranteed they will feature heavily) the monitoring will continue the existing bird counts, bat walks, and vegetation surveys that have been carried out so far – there is an excellent report available that covers this for 2021-2022. Plans are afoot to add in Flower-Insect Timed Counts to contribute to the UK Pollinator Monitoring Scheme and various other invertebrate recording schemes.
Habitat management and improvement works will also be part of this job where establishing new reed beds in the Lea will create cover for water birds and serve as a natural filter for some of the litter and pollutants in the river. Silt traps have already been set along the sloped concrete banks and have become vegetated, and we hope to be able to extend this work further along the east bank. Additionally, there are other areas on or near the industrial estate that can be better managed for wildlife and people including woodland, scrub, and parkland which will entail a number of different projects.
My vision for this stretch of the Lea is that it acts as a green and blue corridor through this part of east London which has a very industrial heritage, but which is now rapidly being redeveloped with high-density housing. The river serves as the boundary between the boroughs of Newham and Tower Hamlets. These are already densely populated areas (Tower Hamlets has the highest density per km of all English districts, while Newham has the 4th highest population of all the London boroughs) with high levels of poverty (Tower Hamlets has the highest poverty rates in London with Newham ranking 3rd highest). Consulting with property developers at sites in both boroughs to offset some of the habitat loss caused by building apartment blocks as well as helping to shape a nature-friendly approach to the landscaping will also be part of the job. The loss of post-industrial brownfield sites to development is of concern and we will be working to try to mitigate this through the establishment of green roof systems that mimic traditional brownfield habitat as well as advising on the best use of pocket parks and identifying areas to be set aside as wilder habitats.
Working as FSC BioLinks Project Officer has been a fantastic experience. Some of my highlights over the past year-and-a-bit have been my reintroduction to aquatic invertebrates after spending such a long time focussing on all things terrestrial – there is so much to see underwater, and you get to have a bit of splash about which is especially fun on a hot Summer’s day. Formalising my self-taught ant ID with a number of courses (some of which I even got to teach!) and running my version of an Ant Picnic at Richmond Park where I got youngsters to do science while looking at ants. Rediscovering woodlice, millipedes and centipedes; finding the Downland Villa Bee-fly, Villa cingulata, in abundance at Bushy Park; visiting so many amazing sites in and around London from hidden gems to publicly accessible thoroughfares – the list goes on and on.
It has been fun and an absolute privilege to work across so many different invertebrate taxa. I recently presented some of the findings from the project at the BioLinks Legacy Conference (the final report will be made available to the public in due course) at the Wellcome Collection in London and am very proud of the work that our team managed to accomplish despite a global pandemic in the middle of our project delivery.
I have learned so much more about a wide variety of invertebrates from national experts (further improving my ID skills) and came to meet a community of people who are passionate, enthusiastic, generous, and knowledgeable about our natural world and the invertebrates upon which we all rely. My sincere thanks to every person who I’ve met along the way and I very much look forward to seeing and working with many of them again in the future.
Set a couple of blocks back from a busy inner city A-road and tucked up against the back of a Sixth Form School is a little patch of greenspace that is the Bethnal Green Nature Reserve. Often overlooked, this volunteer run space offers a little patch of tranquility in the heart of Bethnal Green. I have volunteered here on an ad hoc basis over the year helping with woodland management, pond restoration, turning compost, and whatever else needs attention. This has been a great way to spend a Saturday morning – getting my hands dirty and chatting with other local people who have a stake in the space.
It has also been a perfect place for me to explore my growing interest in invertebrate macro photography and I’m keen to revisit the site again in early 2023 to see what else I can unearth there. There was very little knowledge of the invertebrates living at and using this site with no records submitted to the local environmental records centre. Without any formal recording plan and following the site’s ethos of ‘tread lightly & do no harm’ I have now added 152 invertebrate records across 82 species for the site. And I’m sure this has only scratched the surface.
I was also lucky enough to be invited to spend a few days with some of the site volunteers looking at the different habitat types and the invertebrate assemblage types that are found here. Below are photos taken by the volunteers at these various events.
A series of half-day-long events were organised to explore the invertebrates of Bethnal Green Nature Reserve. Attendance was fantastic and I would like to thank everyone who came along and participated – even those who were a little less keen on our invertebrate neighbours than some others. We looked at nocturnal, pollinating, pond, and leaf litter & soil-dwelling invertebrates. I certainly had a fantastic time and I believe that the volunteers now all have a greater consideration and appreciation for the invertebrate life that is found here. I think this is exemplified by the video below of a Willow Emerald Damselfly (Chalcolestes viridis) captured from the edge of the pond, which was shared in a WhatsApp group by one of the volunteers.
This is a good start. There’s a lot more to be done here in terms of understanding the invertebrate fauna of the site, but there is a willingness, even an eagerness, to do so. I hope that I will be able to support and attend more of these activities over the coming years while we get to know this little urban oasis and all of its many inhabitants better.
To help with this I have now created an iRecord activity where future records from the site can be entered so that they are all kept together and start to build a clearer impression of all the life here as seen and recorded by the people who love and use the site.
The piece was written in response to a comment made by an attendee at one of the Learn to Love Ants courses that I was teaching, where the person remarked that the lives of ants seem much like the fantasy series Game of Thrones. And there are certainly parallels that can be drawn between some of the observed behaviours of ants and the tropes of deception, brutality, conquest, and conflict that are rife in the fantasy genre.
There is of course much more complexity in these social insect societies than just these cherry-picked sensationalist topics, such as: brood care; mutualistic interactions with other organsims; the recently documented care for injured Matabele ants by their sisters; and many more besides. After all, as Sansa Stark says: “I’m sure cutting off heads is very satisfying, but that’s not the way you get people to work together”.
In the run up to both COP 26 and COP 15 many newspapers recently reported the shocking fact that Britain has lost almost half (47%) of its biodiversity since the industrial revolution. For naturalists and conservationists working in the UK this will,however, come as absolutely no surprise whatsoever.
Research by Prof Andy Purvis from the Natural History Museum in London showed that Britain is one of the most nature-depleted nations in the world, well below the global average of 75%. With the publication of the Biodiversity Intactness Index (BII) we can now clearly see in the data what naturalists have been warning about for decades from their field observations – Britain’s biodiversity is in peril.
What’s the deal with biodiversity anyway?
‘…Biodiveristy provides us with the food we eat, from the micro-organisms that enrich the soil where we grow our crops, to the pollinators who give us fruit and nuts… [and] many of our medicines originate from plants and fungi…’.
Sir Richard Attenborough
This beautiful animation (below) narrated by Sir David Attenborough and produced by The Royal Society explains the importance of biodiversity, both to us and the world at large.
When 67% of the UK is used for agriculture and a further 8% is built on that leaves a paltry and dwindling 25% for nature. According to official statistics from the Ministry of Housing, Communities and Local Government (2018), forest, open land and water constitute 21% of all land use in England.
‘As Presidents of COP26, the UK has put nature at the heart of the agenda, and we very much welcome this important study which highlights the crucial connections between climate and biodiversity and the urgent need to protect nature’.
Lord Zac Goldsmith, UK Government Minister for Pacific & the Environment
Damningly though, researchers from the RSPB have found that although 28% of UK land is reported by the UK government to be protected, only 11.4% of land area actually falls within protected areas designated primarily for nature conservation. And because of the poor condition of some of these areas, as little as 4.9% of UK land area may in reality be effectively protected for nature.
How do we effectively address this issue in Britain?
‘Governments possess the power – economic, political and legal – to address the planetary emergency, and there may still be time, but they must act now.’
Prof Andy Purvis, Natural History Museum
The British Ecological Society produced a report in May this year (2021) that called for a nature-based approach to tackling both climate change and biodiversity loss in conjunction with other climate and conservation actions. A brief summary of their specific policy recommendations provide examples of opportunities across a range of habitats through:
Restoring degraded peatlands and end burning on blanket bogs
Increasing native woodland and woodland connectivity in the right places
Establishing more saltmarshes
Protecting and re-establishing hedegrows in arable landscapes
Increasing agroforestry in arable landscapes
Increasing urban green spaces with a focus on native species
Unfortunately, any and all action to prevent further biodiversity loss is costly. A recent report from the Green Finance Institute claims that the UK governement faces as much as a £97 billion funding gap for its current commitments to nature-based actions over the next 10 years.
Regardless of the financial costs of mitigating and remedying biodiversity loss, we should never lose sight of the costs of inaction – not just economic, though these are significant. But also the legacy of a pillaged, spoiled and empty landscape; a depauperate and diminished native biota; and ultimately, an impoverished and increasingly precarious society.
I am a self-professed invertophile. I absolutely adore the myriad forms of insects and other spineless creatures. They are the most diverse and abundant group of organisms on earth, they can be found in every habitat imaginable, they have evolved some of the most complex forms, lifestyles and behaviours, and they are responsible for maintaining essential ecosystem functions and systems. How could one not be utterly awed by them?
I grew up in South Africa and lived on the outskirts of a small town in KwaZulu-Natal. I played on the edge of wilderness and ‘civilisation’ where the veldt and acacia scrub met our mowed lawn and meticulously weeded flower borders. The garden was surrounded by a low wall built from great chunks of blue-grey and rust-coloured igneous rocks (which were displaced by the flower beds) and poured concrete. I travelled in a circuit along these walls and around the garden marvelling at all the life that was to be found here: Citrus Swallowtail butterflies and their peculiarly pungent caterpillars that were resident in our lemon tree; ants that magically appeared around every dropped crumb; checkered yellow and black blister beetles which I knew not to touch; the iridescent snap of a dragonfly’s wings as it hawked overhead. I also kept my share of ‘pets’ that wandered too close to the house and ended up living in jam jars with holes punched through the lid. As I grew older the farther I wandered from the borders described by the walls, drawn further and further away by the towering curiosities that rose out of the earth and teemed with thousands of milky-white termites. I watched trapdoor spiders snatch up prey, ran with solifugids and scampered from scorpions. I carefully turned over logs and rocks and watched centipedes and beetles scurry from the light. I listened to the susurrus hiss of grasshoppers, and when those turned to the chirps of crickets I knew that it was time to head home for dinner. My childhood summers were glorious and almost every day was filled with LIFE.
Now, much later in life and living in London, I still find the presence of wild animals very rewarding. And still, none more so than the invertebrates. They are perhaps not as abundant or as large as those of my youth, but they are all around us even if we need to look a little harder. I now have a number of local patches where I go to observe invertebrates. All within a comfortable walking distance of my apartment and all quite different from one another: a local park, a cemetery and urban nature reserve, a city farm, a medicine garden and community space, and a brownfield site. So far this year I have recorded many species new to these sites, several new to the borough and new to me!
Although I understand that not everyone shares my passion for the myriad creatures that surround us and that some people can be downright hostile towards them; I can’t help but feel that they’re missing out on something quite incredible. And to that point I’ve been thinking a lot about observing and recording invertebrates recently – specifically about how people might get started with it.
How to get involved
There are many ways in which you can become involved with observing, identifying and recording invertebrates. Here, I will specifically discuss casual recording – by this I mean randomly walking through a space of your choosing and observing invertebrates in situ. There are no formalised procedures, no sampling methodologies, just you in nature. I think that this is a great way to become familiar with the variety of life out there. Having said that, you will find a few items incredibly useful for helping you along your new voyage of insect discovery:
Comfortable walking shoes,
A good introductory or general field guide,
A camera (a phone camera will most often work well enough),
A GPS or phone that can give you location coordinates,
A notebook and pen/pencil,
A 10x magnification hand lens.
I will follow this blog post up with another about different invertebrate sampling methods in the future.
A note on some of the field guides that are available: the Collins Complete Guide to British Insects by Michael Chinery, though by no means complete, is a decent place to start as it covers many of the more common species (>1,500) and was in fact my first field guide. I then moved on to Paul Brock’s A Comprehensive Guide to Insects of Britain and Ireland which, though not comprehensive, goes somewhat further than Chinery, covering more species (2,300) and also includes some of the rarer insects. Most recently (2021) Brock has published Britain’s Insects with WILDGuides which focuses on more popular groups and species. This is an interesting publication with some excellent entries and photography, but covers a reduced number of species (1,653). I own and regularly use all of these but also more specialist guides to various groups of insects. However, when starting out, I would recommend that you get one of these to use in the field and will point out some of the excellent online resources and forums that are also available. Please note that these books are available through other bookshops and online sellers, I have linked to NHBS as they actively support conservation.
How to find invertebrates
Stop. Pick a spot and stand still.
Get your eye in. Let your eyes slowly scan across the vegetation in front of you just below eye-level. Look for movement, see if there are any odd shapes or colours that stand out from the background. Remember many insects can be very well camouflaged so take your time.
Get down low. I tend to crouch a lot, but you could also kneel or sit on the ground. If you’re low down you will be more likely to see ground-dwelling invertebrates. This is why young children make fantastic “bug hunters”.
Listen. Some insects will make noise to attract mates like crickets and grasshoppers, but you can also hear the snap of dragonfly wings, the rustle of grass as something moves through it, and even the munching of leaves.
Move slowly and carefully. Don’t move far, but move a few steps at a time while keeping an eye on where you place your feet. As you move you want to try to avoid disturbing the vegetation as much as possible as invertebrates can be very sensitive to vibrations. Also, beware your shadow as this can frighten off the flightier individuals.
Look forsigns of invertebrate presence. Nibbled leaves, cut stems, silk threads, nest holes and the like. Sometimes even tracks in sand can be signs that invertebrates are about; and always keep an eye out for frass (essentially larval poop).
Don’t forget to look up. Remember that many insects can fly. Also, it is definitely worth examining vegetation at or just above head height.
Make notes and/or take photos. This is very useful for your own future reference, but also if you want to report your sightings to any of the recording schemes. I will talk about this in a bit more detail later on, but basic information that is useful is: a photo, the date, species name, number seen, and location.
Through recording wildlife we can determine a number of important data about what animals are found in which habitats. With long-term data we can see if these species change over time and this can help us to understand the drivers of those changes e.g. habitat loss, pollution events, land restoration etc. We can track the movement of species’ distributions in response to large-scale and seasonal effects such as climate change, and we can monitor the conservation status of species in order to identify those most at risk of extinction. Invertebrates are specifically important because it is in their changes that we tend to first detect issues of future conservation concern. I hope that I’ve managed to convince you that this is a worthwhile project to undertake for better understanding these incredible creatures that share the planet with us.
In Britain the recording community is largely voluntary, from people going out into the field to record what’s in their local patch to the experts who verify these records and the county or national recorders who collate it all. There are of course exceptions such as ecologists who might be employed to survey sites for invasive species or for endangered species that might affect construction projects. But for the most part people survey and submit records for their own personal reasons which can be as varied as the number of people involved; whether that’s about wanting to contribute to scientific enquiry, wanting to know more about the wildlife in a local area, or wanting to catch them all…
How to record invertebrates
Recording invertebrates is a two-step process. The first step is what information is kept in your field notebook. I tend to record a bit more information here than I will need for submitting to the recorders/recording societies.
On a new page in my field notebook I always start with this information:
Weather – the general outlook for the day.
Site notes – you may want to specify habitat type(s) or whether there has been any site management or disturbance since your last visit etc.
Casual recording – or specify which sampling method was used.
I then start searching for invertebrates and record them each like this:
Species name – if known, otherwise genus or family and update it later.
Male / Female / Mixed – if you can tell, it isn’t always possible.
Life stage – adult, larva, nymph, pupa, etc.
Identified by – this is if someone else has helped you with an ID.
Number – you need to decide on the scale you want to use here, I tend to include all individuals within 102 metres, but you can extend this to 1002 m or 12 km if you want to include a whole site.
Coordinates – I normally get latitude and longitude from my phone using either Google Maps or Apple Maps in decimal format.
Photo number – if using a camera that records this information.
Notes – any significant interactions or interesting behaviours.
And that’s it!
The second step is to submit your records and there are a few different ways in which you can do this. For the most part I use the online recording website iRecord which a large number of verifiers and recorders use. For more information about how iRecord works take a look at this blog post and video produced by Keiron Derek Brown.
Alternatively you can manage your own database in Excel and provide these records to the national recording scheme or relevant recorder directly via email if that’s what they would prefer.
The more you look…
I have lived in Tower Hamlets for 10 years and in the last few months I have been incredibly fortunate to find three endangered insect species in some of my local patches. This is because I have spent more time looking and got lucky. This is what makes casual recording so exciting for me, you just never know what might turn up.
I’ve spent the last couple of months in the Taita Hills in SE Kenya where I am studying the impacts of anthropogenic habitat degradation on bird functional diversity and composition. Specifically, I’m working in a sky island complex of massifs topped with remnant montane forests that form the northernmost extent of the Eastern Arc Mountains. The forest fragments on these hills are designated as Key Biodiversity Areas (KBA) and Important Bird Areas (IBA) because of high levels of endemism and biodiversity. This area is ideal for this research as it shows very high levels of historical habitat fragmentation and different degrees of degradation through various human land-uses.
I am starting with characterising the bird communities of the different forest fragments and the surrounding agricultural matrix by identifying bird species via point counts & AudioMoth sound recordings. This data will be combined with an existing traits database so that we can determine what functional roles are present (and to what extent) in each habitat.
Another approach that we’re using to try to understand how effective birds are at controlling pest insects is by using plasticine model “caterpillars”. The attack marks that are left behind help us to identify the levels of predation relative to habitat quality.
This lays the foundation for my next field season when we will be capturing birds to collect faecal samples which will be analysed using DNA metabarcoding. This will provide us with information on how birds’ diets are influenced by habitat quality and also allow us to quantify the ecosystem functions that birds perform – like controlling herbivorous insect pests and seed dispersal.
Note that this content is from an article I wrote as part of my BSc degree in 2014. The latest reports indicate that coffee production and consumption have both increased since the slump of 2013 – 2016, while prices have shown a downward trend. Despite this, I think that the article remains relevant especially concerning coffee production and means of mitigating the inevitable effects of climate change.
Originating in the horn of Africa with cultivation possibly starting in Yemen around six
centuries ago, coffee is now one of the most popular hot drinks worldwide1. After oil, coffee is the world’s second-most traded commodity with 93.4 million bags, worth a staggering US $15.4 billion (£9.27 billion) exported from coffee-growing countries in 2009/2010. Now it seems that the world’s coffee-producing regions may be under threat from the effects of climate change, according to Aaron Davis and Justin Moat from Kew.
By all accounts, we love our coffee, with nearly a third of the world’s population drinking it. The USA imported almost 27 million bags between November 2012 and October 2013 while the UK imported around 4 million bags over the same period, according to the International Coffee Organization (ICO). In total, worldwide imports for the 2012/2013 coffee season were an astonishing 133.9 million bags.
Reduction in productivity, increased and intensified management, and crop failure.
Of the 125 species of coffee plants found naturally, the two main types used in the production of coffee are arabica and robusta. Originally from the high-altitude, humid evergreen forests of Ethiopia and South Sudan, arabica is known to be climate sensitive with an ideal average temperature of between 18°C and 23°C and well-defined rainy and dry seasons. Arabica coffee is now grown in 52 countries worldwide. Robusta, as its name implies, is more comfortable with higher temperatures and produces a greater crop yield than arabica. With its higher caffeine content and more bitter flavour, robusta tends to be used in instant coffees while arabica is considered superior in quality and taste making up 70% of all commercially produced coffee. There are now thought to be around 26 million people working in the coffee sector worldwide. Our demand for coffee has never been greater and yet a series of climate-linked and interrelated problems such as increased temperature, unpredictable rainfall, the spread of insect pests and diseases, intensive farming, and urbanization could spell the end of coffee as we know it.
It’s getting hotter
Ethiopia (the fifth largest global exporter of coffee and Africa’s main coffee-producing nation) was used as an example by Davis and Moat when they looked at the possible future distribution of arabica coffee. They based their findings on the Intergovernmental Panel on Climate Change’s (IPCC’s) best estimates of anticipated temperature rises of 1.8°C to 4°C in global temperatures by the end of the twenty-first century and found that coffee production was likely to decrease significantly. Worryingly, they also found that there would be less land that is suitable for growing coffee, saying that it would lead “…to a reduction in productivity, increased and intensified management…and crop failure.”
Countries whose economies depend heavily on agriculture for their development may be hardest hit by a change in climate.
Responding to warming temperatures, some farmers are starting to grow their crops further up hillsides and mountain slopes. At higher elevations, where the temperature is slightly cooler, the arabica plants thrive once again. It is, however, harder to farm at higher altitudes and we cannot keep going up the mountains, we’ll simply run out of farmable land. There is also expected to be a climatic shift in latitudes so that the tropics and subtropics effectively move away from the equator, but this is incredibly difficult to predict because of air currents, ocean currents and local geography all affect this and act on one another. In a report by the International Trade Centre (ITC) entitled ‘Climate Change and the Coffee Industry’ the authors note that any shift in altitude or latitude may adversely affect the quality of the coffee and fewer parts of the world may end up being able to support arabica coffee production.
As air and ocean temperatures rise, it is likely that wet areas will get wetter and dry areas will get drier according to both the ITC and IPCC. This is the rule-of-thumb measure for regions, but there is also expected to be far more variability; that is, more extreme droughts and more heavy rainfall. The increased warming will mean that for every 1°C increase in temperature the plants and animals that live in a certain area because the climate conditions are perfect for them there will have to shift by 160 km (about the distance between Birmingham and London as the crow flies) north or south, following those perfect conditions. In the case of some island nations a 160 km shift could be catastrophic. We should expect more humidity and higher rainfall to accompany the hotter tem- peratures. The seasonal and geographical rainfall and temperature patterns that we have all grown used to will change because of these shifts. This is of course incredibly bad news for arabica which needs quite particular weather conditions.
Intensive farming methods
The way in which the coffee is grown can also contribute to some difficulties. Traditionally, coffee was grown under taller trees and shrubs of different heights with a large mix of plant species. This meant that the coffee plants grew in shade and that the soil was rich with the nutrients of all of the accumulated dead plant matter. On a number of farms this method of growing has been abandoned in favour of plantation-style planting which means that the farmer can squeeze more plants into an area and improve the size of the yield. This involves clearing the land by chopping down the trees, sometimes burning, and planting sun-resistant varieties of coffee that have been bred to tolerate growing in direct sunshine. This intense planting regime also requires the addition of many tonnes of expensive man-made fertilizers and chemical controls such as fungicides and pesticides every year. These changes in production practices have been found to exacerbate the problems associated with coffee-growing according to Juliana Jaramillo, from the Institute of Plant Diseases and Plant Protection, at the University of Hannover in Germany. Studying a coffee-producing area near Nairobi in Kenya, Jaramillo and her colleagues found that open plantations were 2°C higher than shaded ones. Obviously, the associated warmer temperatures are a problem for arabica growing, but it can also present coffee-growers with a whole new set of problems. The increased exposure to heavy rain can lead to nutrients being leached out of the soil, soil conditions quickly deteriorate leading to soil erosion, and in the worst cases, water run-off that turns into floods and landslides. This becomes a cyclical problem, as crops fail or yields decrease, more intensification occurs to make up the shortfall and worsens the conditions.
The spread of insect pests & diseases
As with any crop plant, coffee can suffer from attacks by insect pests and diseases. With even small temperature rises and changes in rainfall patterns, these pests and diseases become more common and more difficult to control. The coffee berry borer beetle is the most destructive pest of commercially grown coffee, causing crop losses of more than US $500 million (£300 million) per year. These beetles actually benefit from increases in temperature. Based on a 1°C temperature rise over the next 50 years, Jaramillo expects to find the beetles reproducing faster and spreading further. Even now the insects are being found 300 metres higher up the slopes of Mt. Kilimanjaro in Tanzania than where they used to be ten years ago.
A devastating outbreak of coffee leaf rust in Central America was reported by Reuters News Agency in July 2013. The rust is very damaging to crop yields and was responsible for a 15% drop in production from the region last season with even worse effects expected for 2013/2014. Warm temperatures and high humidity are ideal conditions for the rust to spread, but it also needs the leaf that it is colonising to be wet to be able to first become established. Increased warming and heavier than usual rainfall in the region has created the perfect incubator for the rust. Ironically, another fungus, the white halo fungus, which attacks and partially controls the spread of the rust
has been wiped out by the systematic spraying of chemicals. “What we feel has been happening is that gradually the integrity of this once-complicated ecosystem has been slowly breaking down, which is what happens when you try to grow coffee like corn,” said US ecologist John Vandermeer.
The integrity of this once- complicated ecosystem has been slowly breaking down.
Rather than responding to temperature rises, the coffee white stem borer beetle, a major coffee pest in Zimbabwe, is becoming more common because of changes in rainfall. Adult beetles emerge from the infested coffee plants in the rainy season and with increased periods of rainfall up to 200% more beetles are expected there by the year 2080 says Dumisani Kutywayo and colleagues from the Coffee Research Institute (CRI). A quarter of Zimbabwe’s yield losses are due to infestation by coffee white stem borer and as rainfall patterns become more unpredictable and seasonality shifts, coffee farmers’ outlook can only be described as gloomy.
What is to be done?
In the face of catastrophe, all is not lost. The planting of coffee plants under a mixed canopy of plants has shown time and again to be a very effective model for controlling temperature. This form of planting is known as agroforestry and apart from creating more favourable conditions for coffee growing also allows the farmer to grow an additional crop such as bananas. This model is already in use across the coffee-growing world and as Helton Nonato de Souza from the Department of Soil Quality, Wagenin- gen University in The Netherlands explains: agroforestry creates shade, maintains a cooler air temperature, improves the condition of the soil, retains soil moisture, and limits damage from high rainfall. In their study area in the Brazilian Atlantic Rainforest, de Souza and his team also identified not only a vast array of tree species average of 60% greater biodiversity than the surrounding forests.
This species richness is an invaluable part of a healthy ecosystem and contributes to the well being of the coffee plants through biological controls. Pests and diseases can be controlled by their natural predators instead of chemicals as long as we provide a space for them to live according to the US ecologist, Daniel Karp.
There is also ongoing research into developing new breeds of arabicas that are less heat-sensitive or show more resistance to pathogens and diseases. Returning to the birthplace of coffee; some coffee plants with resistance to extremes in temperature have recently been found in the Ethio- pian Great Rift Valley.
90% of all coffee production is located in the developing world.
All the signs regarding arabica coffee growing in an age of global climate change are troubling. We must expect that production will probably decrease, that quality may be affected, prices will rise, and that the livelihoods of millions of people are at risk. With many farmers finding conditions more difficult with less income, there is the real risk that intense production of higher-income cane sugar, palm oil, cocoa leaf or khat replace coffee. What is needed is a reevaluation of the pricing structure of coffee linked to new patterns of behaviour that value the wider natural system within which it is grown. With the fair financial support of consumers, coffee farmers will be able to take steps to protect their livelihoods from the devastations of unpredictable rainfall, increasing temperatures and the growing abundance of pests and diseases. There is now an opportunity for more farmers to embrace small-scale, shade-grown coffees that will benefit the wider environment, keep their businesses sustainable and keep producing good quality coffees.
As a Roaster from a coffee company in London said in an interview for this article: “The consumers have the knowledge, the power and the resources to do something proactive. If the consumer is willing to pay more from an ethical company … then the farmers have the resource to invest in strategies that will help to mitigate the issue [of climate change].
Jaramillo J, Setamou M, Muchugu E, Chabi-Olaye A, Jaramillo A, et al. (2013) “Climate Change or Urbanization? Impacts on a Traditional Coffee Production System in East Africa over the Last 80 Years.” PLoS ONE 8(1): e51815. doi:10.1371/journal.pone.0051815
Kutywayo D, Chemura A, Kusena W, Chidoko P, and Mahoya C. (2013) “The Impact of Climate Change on the Potential Distribution of Agricultural Pests: The Case of the Coffee White Stem Borer (Monochamus leuconotus P.) in Zimbabwe.” PLoS ONE 8(8): e73432. doi:10.1371/journal.pone.0073432
de Souza HN, de Goede RGM, Brussaard L, Cardoso IM, Duarte EMG, Fernandes RBA, Gomes LC, and Pulleman MM. (2012) “Protective shade, tree diversity and soil properties in coffee agroforestry systems in the Atlantic Rainforest biome.” Agriculture, Ecosystems and Environment. 146, 179-196
Jaramillo J, Muchugu E, Vega FE, Davis A, Borgemeister C, et al. (2011) “Some Like It Hot: The Influence and Implications of Climate Change on Coffee Berry Borer (Hypothenemus hampei) and Coffee Production in East Africa.” PLoS ONE 6(9): e24528. doi:10.1371/journal.pone.0024528
Jackson D, Skillman J, and Vandermeer J. (2012) “Indirect biological control of the coffee leaf rust, Hemileia vastatrix, by the entomogenous fungus Lecanicillium lecanii in a complex coffee agroecosystem.” Biological Control. 61:1, 89-97
Erickson J. “Modern growing methods may be culprit of ‘coffee rust’ fungal outbreak.” Michigan News: University of Michigan. 12/02/2013http://www.ns.umich.edu/new/releases/21192-modern-growing-methods-may-be-culprit-of-coffee-rust-fungal-outbreak
Karp DS, Mendenhall CD, Sandi RF, Chaumont N, Ehrlich PR, Hadly EA, Daily GC. (2013) “Forest bolsters bird abundance, pest control and coffee yield.” Ecology Letters. 16:11, 1339-1347
Gonthier DJ, Ennis KK, Philpott SM, Vandermeer J, and Perfecto, I. (2013) “Ants defend coffee from berry borer colonization.” BioControl: Journal of the International Organization for Biological Control. 58:6, 815-820
Inspired by Gilbert White (naturalist, ornithologist and author of The Natural History and Antiquities of Selborne) the Selborne Society was formed in 1885 as Britain’s first national conservation organisation. Members of the Society went on to establish pre-eminiment organisations such as the National Trust and Royal Society for the Protection of Birds. Today, the Society manages Perivale Wood, an 11.6 hectare Local Nature Reserve in Ealing south-west London, where they organise an open day, and a wide range of indoor meetings and field excursions.
I was invited to talk to the Society and members of the public about the biology and ecology of ants. This blog post is a very abbreviated form of that talk with a tiny selection of the slides used to give a bit of an overview. To be honest, I was always a bit uncomfortable with the title of the talk. I knew it would be impossible to cover everything to do with ants, so I focused on some of the areas of ant biology that most interest me.
But what’s so special about ants anyway? Well, ants are everywhere. With over 16,000 extant species found in every terrestrial habitat (apart from the polar regions) they constitute a large proportion of all living biomass. Enormously successful as scavengers, herbivores, granivores, predators and mutualists, ants perform important ecological functions as ecosystem engineers and keystone species. Some species are also highly successful at invading new territories where they can become crop pests or outcompete native species for resources. Their eusocial lifestyles also make them ideal model systems for the study of social evolution.
Part of my fascination with ants comes from the tremendous morphological diversity within and between species. Not only can there be differences between castes within species, but species can range in size from the minuscule Carebara atomus (~1 mm) to the comparatively enormous Dinoponera gigantea (~4 cm). I also have a bit of a soft spot for the myrmecophiles (other invertebrates that live in association with ants) and especially the myrmecomorphs (invertebrates that mimic the appearance and/or behaviours of ants). To share some of the beautifully complex variety of forms in ants and the ant-wannabes I asked the audience to play a game that I call “Ant Bingo!”.
Everyone got into the spirit of it and after discussing some of the characteristic features of ants managed to identify all six ants displayed amongst the other fantastic creatures.
Belonging to the order Hymenoptera, the family Formicidae (what we commonly call ants) emerged in the late Cretaceous (~140 MYA) when they diverged from the Apoidea – spheciform wasps and bees. There are now more than 16,000 species of ants in over 470 genera that we know of – it is thought that there may actually be at least as many species still to be discovered. According to some estimates, there are more than 10 quadrillion individual ants alive at any time.
This variety in form is echoed in the highly complex and variable social structures and life histories that have evolved in different ant species. The numerous ways in which they gather food and create shelters to protect themselves from the elements and potential predators are both fascinating and ingenious. In order to feed the colony, there are ants that harvest honeydew from aphids, some that cultivate elaborate fungus gardens, and others that send out raiding swarms that capture anything too slow to get out of their way. For nest-building, there are ants that use larval silk to weave leaves together in the treetops, those that excavate elaborate underground tunnels, and those that have co-evolved with plants to live within specialized swellings and chambers called domatia which are produced by the plants for the exclusive use of their ant protectors. These examples only briefly touch on a few of the magnificent examples of diverse life strategies found within the ants.
There are many different social structures evident between (and sometimes even within) ant species. There are some with single queen colonies and some with multiple queens – in some cases hundreds of reproductive queens can live in the same nest. Queen number can also vary within a species so that there may be colonies with one or many queen(s). The colonies of some ant species can even persist without any queens; in these instances, worker ants can (rather peculiarly) become fully reproductive if the queen dies. These egg-laying workers are called gamergates. At the other extreme, there are the social parasites, where some species don’t produce a worker caste at all – their eggs will only produce the next generations of queens and males. These parasitic queens are known as inquilines, they take over the nests of closely related species who provide a ready workforce so there is no need to expend energy on creating more workers. And then there are what some people call the “slave-making” ants – these ants will raid other nests and carry the brood away to their own nest. The “slave” ants will then work in their new colony, defend it from attack and can even participate in future raids. This process of kidnapping and imprinting is more accurately referred to as dulosis.
I should also emphasise the fact that these social structures may vary over time depending on what life-stage the colony is at. For example, the number of reproductive queens within a colony may vary depending on whether the colony is experiencing a rapid growth phase such as the establishment of a new colony. At this early period, it can be highly beneficial to have many queens all laying eggs at the same time to quickly produce workers to protect the nest, forage for food and care for the brood. But after a time (once the colony is a bit more established) the need for multiple queens is diminished and what was a co-operative breeding chamber becomes an arena for a battle to the death until only one queen remains.
Ants are, in my view, remarkable animals. They have adapted to fill every conceivable terrestrial niche through evolving incredible morphological adaptations, variable social structures, and a dizzying array of life histories. There are also fantastic opportunities for research with many more species to be discovered and behaviours to describe.
This video clip from the BBC2 documentary Natural World: Attenborough and the Empire of the Ants shows wood ants (Formica sp.) defending their nest:
Last Summer I got to revisit an old haunt in South London where I used to volunteer with the London Wildlife Trust. I was very excited about returning to Hutchinson’s Bank Nature Reserve (it is in the suburb of New Addington and easily reached by tram from Croydon). I left the restoration project when I moved ‘North of the River’ some years ago and had not seen the final transformation from scrubland back to chalk grassland. I was not disappointed – this site is a bit of a treat even when the weather isn’t at its finest.
The reserve was taken on by LWT (on behalf of Croydon council) because of the potential to enhance the scrubbed over chalk grassland through habitat restoration & management work and by building on the planting and maintenance already undertaken by a group of dedicated locals who had successfully introduced small patches of Kidney vetch (Anthyllis vulneraria) and Greater yellow rattle (Rhinathus angustifolius). Because of these locals who were actively involved there was also already a very impressive list of butterfly and orchid records associated with the site.
Lowland calcareous grasslands form over shallow limestone-rich or chalky soils which have a typically high pH, low nutrient levels and tend to be free draining. Because they favour these particular conditions, chalk grassland plant species are called calcicoles (lime-loving plants). Much of Hutchinson’s Bank Nature Reserve is, as the name implies, on the slope of an embankment which aids with the drainage of rainfall, and the fact that the slope is south-facing ensures fairly warm conditions throughout the Summer months.
It is estimated that there is between 25,000 ha and 32,000 ha of chalk grassland in the UK1 where it is considered a nationally rare habitat. Calcareous grasslands have been described as being equivalent to coral reefs in terms of their species richness, and though this can be seen in small areas, the comparison doesn’t really hold once you increase the scale of the compared areas. As you increase the study area on a coral reef, you will continue to find new species at a higher rate than in chalk grasslands where you will fairly quickly find all the resident species, relatively speaking.
This notwithstanding, calcareous grasslands are highly species rich with a single square metre supporting between 50 and 60 species of vascular plant (including 37 Red Data Book species). As a result of this habitat heterogeneity, we find variation in vegetation structure and large numbers of different food plants which cater for one of the most diverse insect communities in Britain.2
What makes these habitats especially rare is the fact that they are remnants of Mesolithic agriculture; established about 9,500 to 5,000 years ago when forest cover was cleared for growing crops and rearing domestic animals which continued well into the Neolithic era. The highly porous soils meant that nutrients leached away and that these largely-unfertilized fields eventually lost productivity and were abandoned for new sites. But while they were productive, they were kept clear of encroachment by scrub and the succession to closed-canopy forest was inhibited.2, 3, 4 These cleared areas would then support grass swards and herbs associated with both steppe and Meditteranean vegetation types whose seeds had previously lain dormant in the soil seed bank. This anthropogenic land management system involves quite a specific regimen, and though supported by some historical pollen records and fossilised beetle fauna, it remains unresolved.4, 5
In 2000, Frans Vera proposed a new hypothesis to explain open patches of land (much like savannahs) based on the same evidence but concluded that these areas were maintained by large herbivores such as auroch, wild horses and deer. The Vera Hypothesis, as it has come to be known, remains controversial and has become the basis for a large-scale rewilding experiment at Oostvaardersplassen in the Netherlands. It is likely, in my view, that a mosaic of open areas was first created for agricultural use and then maintained by browsing and grazing of ungulates.
With this in mind, it is therefore interesting to view a map of Hutchinson’s Bank Nature Reserve from 2012 which shows the management plan for different areas including removing topsoil (the most recent land use was modern agriculture, rotational grazing and cutting back scrub. These accepted chalk grassland management practices6 are very similar to those used by Mesolithic farmers ~9,000 years ago.
The largest threat to chalk grassland ecosystems is therefore a lack of correct management which leads to encroachment of scrub and eventually reforestation. Add to this past (and perhaps recurring) socio-economic pressures to develop high-yield crops and provision of housing, and the threat becomes compounded. With only 29% of lowland calcareous grasslands assessed as SSSI being described as favourable by the Joint Nature Conservation Committee, there is real cause for concern. However, an additional 40% of sites are described as “unfavourable recovering”, but without any indication of what that means for each site in terms of actual improvement over time I am unsure of how much solace one can draw from that number.
It was on one of my volunteering days in August 2011 that we went to another chalk grassland managed by LWT nearby. We were here to survey the vegetation, plot the exact perimeter and identify areas for habitat management.
Saltbox Hill SSSI is located near Biggin Hill airport and is on a very steep hillside with ancient woodland on the ridge of the hill. With an impressive species list and located near the home of Charles Darwin, this area undoubtedly has natural history kudos, and it was here that I found one of the strangest looking insects that had me puzzled for quite some time.
Some small square sheets of corrugated iron had been set out to act as refugia for the resident slow worms and snakes. Sitting on the edge of one of these sheets was a segmented, rather hairy, caterpillar-like insect. I was completely stumped. I just about managed to get a photo with my phone and as soon as I got home I turned to the internet for help. iSpot is a very useful resource for these baffling discoveries – experts and amateurs alike will help with an ID of any species from a photo and some habitat information. Within a matter of hours I had an ID of Drilus flavescens. Turns out my insect was the female larva of a highly sexually dimorphic beetle found in chalk grasslands. It has a very limited range and is classified as scarce in the UK. Fascinatingly, the males look more like traditional beetles as adults, while the females remain looking much like their larval form. You can find more information at Mark Telfer’s excellent website here.
A visit to a chalk grassland in Summer is a complete sensory immersion. I implore you to go and walk through the grasses skirting the ant mounds; smell the heady herby scents of wild thyme and oregano as you brush past; be surrounded by the buzzing of bees and flies and the soft susuration of grasshoppers; and be dazzled by the sight of brightly-coloured flowers and dancing butterflies. These are spaces that celebrate the wonder of life. I am heartily looking forward to another visit this year.
Price, E.A.C. (2003) Lowland Grassland and Heathland Habitats (Habitat Guides Series), Routledge, London and New York.