Neil Middleton on the 4th edition of Bat Surveys for Professional Ecologists

The 4th edition of Bat Surveys for Professional Ecologists: Good Practice Guidelines is the latest update of the Bat Conservation Trust (BCT) Guidelines and features new content on biosecurity, night-vision aids, tree surveys and auto-identification for bat sound analysis. Several key chapters have been expanded, and new tools, techniques and recommendations included. It is a key resource for professional ecologists carrying out surveys for development and planning.

Neil Middleton is a licensed bat worker and trainer. He is the Managing Director of BatAbility which offers bat-related and business skills development courses and training throughout the UK and Europe. He kindly agreed to take the time to write an article for us which will help ecologists and bat workers assess some of the key content and changes within the 4th edition of the Bat Survey Guidelines, and evaluate how this is likely to impact you, your colleagues and your business.

I have been asked to write this blog for NHBS regarding the recently published 4th edition of the BCT Bat Surveys for Professional Ecologists: Good Practice Guidelines. Straight away I feel I should say that, broadly speaking, we (BatAbility) are supportive of the overall spirit of intent that these new guidelines are seeking to achieve.

The contributors to the finished work and the editor of the final draft will have, I’m sure, had much debate about the final wording of the guidelines. It certainly cannot have been an easy task to come up with approaches that a broad range of experienced people, each with different backgrounds, were able to fully agree upon (or at least not disagree). In addition to which, these guidelines need to cater for all the component parts of the UK, where differences in legislation, planning, licensing etc. apply.

What follows are my thoughts on why you need to be up to speed with what’s happening. When I discuss some of the points you need to be aware of, it’s not that I am criticising or disagreeing with what has been produced, it is more that I am encouraging you to think about things that may not immediately be apparent when it comes to impacting (positively or negatively) upon your daily business operations.

Broadly speaking, these Good Practice Guidelines are what we all need to be referring to now for guidance and, barring any new properly released formal material direct from BCT (i.e. it doesn’t matter what someone says on a social media post or during a webinar) that either updates, changes or gives additional explanation to what is in the 4th edition, this is where we, as a community, are at. BCT have confirmed that a few changes to the text will be made by way of an amendment document and this, in conjunction with printed Q&A material resulting from BCT webinars (November 2023 and February 2024), will prove to be essential complimentary reading for everyone relying upon these guidelines during their day-to-day work.

At this stage, I feel that it is also important to say, and BCT have been very keen to emphasise this point (e.g. during their webinars on the subject), that the guidance is very clear about deviating from its approaches where specific cases and/or experienced, professional judgement suggests that a different approach can be taken for good reason, provided that it is fully disclosed and discussed within generated outputs (e.g. reports going to local planning departments). The material produced is described as ‘guidelines’ after all, and should not be used prescriptively when common sense, good scientific rationale or proportionality, as examples, suggests otherwise.

These updated guidelines were keenly awaited by bat workers for some time leading up to their publication.The driving force behind the update was thought mainly to be the integration of Night Vision Aids (NVAs) into our bat survey approach, as initially described within an Interim Guidance Note published in May 2022 and covered in this article on the BCT website.

I mention this for two reasons. Firstly, it’s what I feel almost everyone was genuinely expecting. Secondly, these revised guidelines don’t (as anticipated rightly or wrongly!) fully address some of the specific aspects of where the NVA debate is going to finally arrive. Regarding this aspect of bat work, the finer detail around this matter is now being tackled by a review panel, and BCT will inform us as/when they are in a position to do so. In the meantime, the Interim Guidance (2022) remains as an additional, essential point of referral. Having said that, within these new guidelines there are regular pointers, reminders and requirements that NVAs should be incorporated within survey design.

So, why do we need to pay any attention to these new guidelines? If they are not telling us about the specifics of the NVA approach, then you may very well think that there’s not much value in getting your own copy and reading through, yet again, what was there before. Yes, you may very well think that. Yes, you would be very wrong.

There is so much in here that is going to make your life as a bat consultant different to how it was up until last year (2023). There are undoubtedly elephants potentially in some people’s rooms. But an hour after sunset when it’s too dark to see, some people may not be aware that elephants lurk (well not unless they have an NVA, and it’s pointing in the right direction). There are resourcing implications, cost implications, tendering implications, health and safety implications – there are all of these and more that you need to be aware of. And by implications I mean a mix of positives and negatives. It is a classic situation whereby in solving a range of issues and making clarifications on others, new issues and opportunities inevitably arise.

From a surveyor’s point of view, the dreaded dawn work is mostly redundant, although I feel there are still going to be occasions from a bat behaviour point of view, and from a health and safety point of view (e.g. working within busy town centre areas) where dawns could still occasionally be a better, or even a desirable approach. The guidelines certainly don’t say you should never do a dawn survey again, full stop.

From a business owner’s perspective there are matters that will need serious consideration and budgeting for. This could impact (again negatively or positively) upon your turnover, your approach to tendering, resourcing, the deployment of staff and equipment, as well as the careful balancing of your team’s time at their desks versus time in the field. All of this, of course, needs to be considered against the benefits to bat conservation. The challenge on the business model is not necessarily a bad thing, provided you are fore-armed and have seriously thought through how these changes impact upon your organisation.

Please don’t construe that I am not supportive of what these guidelines are seeking to achieve. In many respects, from a conservation perspective, I feel things have moved closer to where they should be. Balanced against this, however, I urge you to be aware that you need to get your head around the new approaches as a matter of urgency, and build into your day-to-day workings methods of adapting to the changes.

There is neither the time nor the space to cover it all here, and to do so would merely be to repeat what was contained in the guidelines in any case. What I am seeking to do is alert you to the fact that, despite how much you may have seen on social media etc. relating to the NVA debate, there are arguably equally as BIG matters contained within the new edition that don’t relate to the use of NVAs.

Here are some key points of where things have really changed, in my view:

  • Dawn surveys are pretty much redundant, as we are now pressed to doing dusk surveys with NVAs. This is great from a work-life balance, but it also removes up to 50% of the previously available time slots on your survey calendar.
  • NVAs are to be deployed on pretty much every emergence survey, covering the survey subject as fully as possible, with the associated implications for reviewing all that footage and storage of data. Video footage is much larger than the pure audio that you will have been accustomed to.
  • A licenced bat worker is required to be present for any field work where a licensable situation could occur, no matter how likely or unlikely, be that structures or trees. Following the definite statements in the 4th edition, there is no longer any ‘wiggle room’ on this issue.
  • Bats and Trees – aerial assessment (be that by ladder, rope or MEWP) is pretty much the desired approach, meaning that this will be a greater part of these jobs and, in conjunction with this, licensed bat worker(s) will need to be present.
  • Due to the increased requirement for licensed bat workers to be present far more often than previously was the case, and the increase in tree climbing work where licensed bat worker(s) should also be used, there are resourcing implications that need to be considered when it comes to training in these areas. It is important to be aware that not every licensed bat worker within a business is either capable of or desires to climb trees. Also, in some business models, the licensed person/people are in more senior positions where their presence in the field conflicts directly with the role they are being asked to perform for the business (e.g. team management, client meetings, tendering, business process improvement). So, for some businesses, depending upon their current resources of licensed bat workers, there may need to be a rethink.

What I have described above is most definitely not the full suite of changes, but hopefully it’s enough to demonstrate that you need to get on top of what’s in there.

The key message is, if you haven’t already got yourself a copy and read it through in detail, then as a matter of urgency you should do so. Then you will be able to consider how you are going to achieve what is required.

The 4th edition of Bat Surveys for Professional Ecologists is available as a downloadable non-printable version direct from the BCT website.

Also available as hard copy from – remember to use your BCT membership number to get a 20% discount.

Universal nest bricks

Many UK bird populations have shown a dramatic decline since the 1970s and 80s, with species such as starlings (Sturnus vulgaris), house sparrows (Passer domesticus) and swifts (Apus apus) declining by over 50%. This is thought to be due to changes in land use and agricultural practices impacting food supply and the availability of suitable habitats. Changes in architecture have meant a reduction in important nooks and crannies that are utilised as nesting sites by species such as swifts, reducing reproduction rates in urban areas.

Providing suitable nest boxes has been shown to help increase reproduction rates for many species, helping to boost populations. Stephen Fitt and Mike Priaulx, members of the Swifts Local Network: Swifts and Planning Group, discuss the concept of ‘universal’ bricks, the British Standard key requirements on the inclusion of nest boxes within housing developments and current calls for a more specific national policy regarding these features.

Universal nest bricks

A British Standard BS 42021:2022 for integral nest boxes was published in March 2022. This sets out requirements for numbers, location, dimensions, materials, entrance hole size, and an administrative process to demonstrate implementation on site. This will enable integral nest boxes to provide nest spaces for a wide variety of species, such as house sparrows, starlings, swifts, house martins, and blue and great tits.

The standard also covers nest cups for house martins and swallows.

House martin using a Schwegler swift brick by Hugh Hastings and the Duchy of Cornwall

Some species-specific integral nest boxes are quite inflexible. Sparrow terraces, for example, are rarely fully occupied and are unpopular with other species. Deep nest bricks, such as those designed specifically for starlings, could cause a swift to become trapped within it.

Although swift bricks were designed initially to allow swifts to nest, these are now considered a ‘universal’ nest brick as set out in the NHBC Foundation report: Biodiversity in new housing developments: creating wildlife-friendly communities (April 2021). Section 8.1 Nest sites for birds (page 42) states: “Provision of integral nest sites for swifts is through hollow chambers fitted into the fabric of a building while in construction. Although targeting swifts they will also be used by house sparrows, tits and starlings so are considered a ‘universal brick’.

Swift by Simon Stirrup (Cambridge Bird Club)

The British Standard sets out key requirements for integral boxes as follows:

  • The number of integral boxes in housing developments – at least one per residential unit on average.
  • The numbers of the above installed in larger buildings – to be proportionate to the mass and design; there is not necessarily an upper limit.
  • In all but exceptional circumstances the entrance holes of all integral boxes should be 30mm x 65mm minimum to enable starlings to enter.
  • The entrance hole should be located close to the base of the box to avoid birds becoming trapped within.

This ‘universal’ nest brick concept has also been described in an article by CIEEM, which references a January 2022 paper on this subject by the Swifts Local Network (SLN).

Local policy legislation has also begun to recognise this line of thinking, for example the Westminster Environment Sustainable Planning Document (February 2022), which in particular calls for: “‘swift bricks’ within external walls…Swift bricks’ are also used by house sparrows and other small bird species so are considered a ‘universal brick’. Integrated nesting bricks are preferred to external boxes for reasons of longevity, reduced maintenance, better temperature regulation, and aesthetic integration with the building design” (Species and Habitats, page 49).

The results from Duchy of Cornwall monitoring programmes confirm that by installing high numbers (an average of one per residential unit) of “‘swift/universal boxes’ in new-build developments, approximately 50% showed signs of occupation after five years, so it is highly likely that they will all be used during the lifetime of the building(s) they are situated in.

Swift chicks inside a ‘universal brick’. Image by Dick Newell.

Many conservationists would like to see either a numerical value in the Biodiversity Net Gain methodology for these features for wildlife, or a separate strand to the national policy requiring these to be specified. The BREEAM environmental assessment has been following a similar approach for more than a decade.

Such features are already demanded by specific policies in some Local Plans, but other plans are still being published with no such requirements.

CIEEM highlight in the June 2019 issue of their In Practice journal the value of swift bricks to a wide range of small bird species, and provide readily available best practice guidance on the implementation of the bricks, including a recommendation for one nest space per dwelling on average (in accordance with the BS 42021:2022, and following on from RIBA guidance Designing for Biodiversity published back in 2013). While some local authorities such as Brighton are implementing this guidance, others rely on numbers derived from ecologists’ and planning officers’ advice, which can be very variable.

Some developers, Taylor Wimpey being one example, are publishing their own policies for biodiversity measures such as the installation of integral nest bricks.

Defra are developing a simplified Small Sites Metric for Biodiversity Net Gain, and the consultation on this held during autumn 2021 may provide a glimpse of the future as it asks about including a value for bird and bat boxes in the metric, although this has not appeared in practice as yet.

To find out about the swift nest boxes we sell at NHBS, check out our website.

COP 26: The road to Glasgow… and beyond

In just a few weeks, the UK will host the UN’s 26th Climate Change Conference, COP 26, in Glasgow. In an editorial in the October issue of British Wildlife, David Stroud, former Senior Ornithologist at JNCC and co-author of International Treaties in Nature Conservation: A UK Perspective, describes the build-up to the conference and what we can expect from the event itself. The editorial is shared in full below.

Psychologists tell us that humanity evolved to focus on immediate threats – the sabre-toothed tiger lurking in a cave – rather than to ‘over the horizon’ challenges that will affect us only at some distant time in the future. That, at least, is the suggested justification for humanity’s failure to address seriously the problem of anthropogenic climate change over the last half-century, despite increasingly definitive evidence of the existential threat it poses. The frequency of extreme weather events in recent years, however, no longer allows lack of immediacy to be used as an excuse: from flooding and wildfire to sea-level rise, the consequences of climate change are apparent here and now and they are part of the lived experience of people across the world.

The effects of global heating are not restricted to weather catastrophes. As naturalists, we are ever-more familiar with changes to our flora and fauna, as documented elsewhere in this issue (pages 13–20) and previously in British Wildlife. This presents significant challenges to national conservation policies, which have traditionally relied on essentially static networks of protected areas and protected species lists. Despite the announcement of various welcome (but limited) projects, UK governments are yet to promote or implement climate-change adaptation at the scale required to make a meaningful impact.

The October 2021 issue of British Wildlife

In August, the Sixth Assessment of the Intergovernmental Panel on Climate Change (IPCC) provided the starkest of stark warnings yet (IPCC 2021). This report was described by the UN Secretary-General as nothing less than ‘a code red for humanity’ (UN 2021). He noted that the internationally agreed threshold of 1.5°C above pre-industrial levels of global heating is ‘perilously close… The only way to prevent exceeding this threshold… is by urgently stepping up our efforts, and pursuing the most ambitious path. We must act decisively now…’ With the 26th Conference of Parties (COP 26) of the UN Framework Convention on Climate Change (UNFCCC) soon to be held in Glasgow, the international community has an immediate opportunity to act on this latest science, and to use it as a solution. But will the response be adequate?

The nearly 30-year history of UNFCCC COPs is chequered and has been (rightly) dominated by issues of international development. Essentially, when the UNFCCC was negotiated, developing countries highlighted the need for developed nations – those with the largest economies and the greatest greenhouse-gas emissions – to take primary responsibility for the global issue they had (albeit unwittingly) created by more than two centuries of carbon-driven industrialisation. For this reason, the UNFCCC’s 1997 Kyoto Protocol (of COP 3) was framed on the basis of ‘common but differentiated responsibilities’, placing the primary obligation to address the problem on developed countries (it also, importantly, recognised the contributions to climate change of greenhouse gases other than CO2).

The UNFCCC’s 2015 Paris Agreement (COP 21) made the progressive step of moving away from Kyoto’s top-down assignation of national targets, and instead established a bottom-up approach to delivering objectives through ‘Nationally Determined Contributions’ or NDCs. In essence this allows each country to put on the table what it pledges to do, hoping that this is collectively adequate. Importantly, the NDC approach was agreed by, and thus brought on board, the developing countries – still recognising ‘common but differentiated responsibilities’ while acknowledging that low- and especially middle-income countries also have individual contributions to make to the global solution.

The human development needs of the poorest countries, however, are yet to be met, as recognised by the UN’s Sustainable Development Goals (SDGs). Thus, for affluent nations such as the UK there are actually two requirements for an effective Paris Agreement: not only to offer an adequate NDC, but also to contribute to the ‘financial mechanisms’ that allow developing countries to skip dirty, greenhouse-gas-emitting industry and move directly to green economies. ‘Resource mobilisation’ from the developed world will therefore be a central focus of COP 26.

Media commentators have been calling recently for binding quotas to be agreed in Glasgow. While theoretically desirable, this will not happen and it misunderstands the complexities of the global political process. Should there be a World Government at some point, such a prescriptive approach might be achievable – but for now it lives in fantasyland (along with alternative economic systems). The reality is, regrettably, much messier and is here for the foreseeable future.

At COP 26, the UK has a unique responsibility to ensure a successful outcome. Not only does it have to contribute an NDC of significant ambition as one of the world’s largest economies, but as conference chair the UK has a crucial cheerleader role, with an onus to encourage all other countries to deliver ambitiously, too. Decisions at the COP will, as is the norm for such meetings, be taken by consensus, which leaves a real risk of lowest common denominator decision-making because all countries effectively hold a veto. The role of the UK diplomatic services here is critical to build momentum, impetus and pressure (as was that of France ahead of 2015’s COP 21). They also have a vital job in gaining prior intelligence from other countries and working to fix problems and issues ahead of time through face-to-face dialogue in other capitals. As at all intergovernmental COPs, most of the content of decisions is developed well beforehand, while the conference itself is used to finesse the details and formally sign off the final texts. With (we hope) all 197 Contracting Parties attending and just a few days available together in Glasgow, there is no time to do otherwise.

Parties will already have prepared their broad national negotiating positions over the course of the last year, not least because for a meeting of such significance these will typically need to be agreed by the head of government. Many parties work together, giving them greater collective influence. National positions further evolve within regional and other negotiating blocks, including the 27 member states of the EU; the G77 (a coalition of 134 developing countries) and China; the African Group; and the multiple Small Island Developing States which, faced by pressing existential impacts from rising sea levels, have become an increasingly influential political force in climate negotiations.

Yet ultimately, while civil servants can prepare much of the ground, at the COP the tough, final negotiations and trade-offs will be undertaken by heads of government and their ministers. In this, simple peer pressure is important: no national politician likes to be presented as internationally unambitious. And personal relationships, as in any negotiation, are key to success.

Public pressure can also play an essential role by creating a political climate in which it is easier to commit to difficult things when they are presented as ‘the desire of the people’. The last few years of school strikes and other radical actions have demonstrated great public concern, rendering it increasingly difficult, for European leaders at least, not to engage. Hence, the environmental community has an important lobbying role, reminding politicians of what is expected from them, not just ahead of the COP but crucially after it as well, and holding governments globally to account. Commitments are easy to make, but also easy to forget (especially when they involve tough policy changes), and an important agenda item at COP 26 will be the first global stocktake on progress in implementing the measures agreed in Paris.

Beyond governments, contributing to the necessary profound societal change involves all of us. The latest form of climate-change denial is to accept the reality but to make no consequential alterations to one’s lifestyle: ‘business (and life) as usual’. Yet everyone will need to make changes – not least to rediscover the much-anticipated (but so far elusive) ‘new normal’ that was predicted to emerge from the Covid-19 pandemic. This will include switching urgently to more sustainable modes of transport, insulating our homes, changing diet and, critically, reducing consumption and having simpler lifestyles: buy less and live more. In promoting such behavioural changes, the environmental community has an important leadership role within society. Gandhi stressed the need to ‘be the change you want to see in the world’. Exactly.

IPCC. 2021. Sixth Assessment Report.
UN. 2021. Secretary-General’s statement on the IPCC Working Group 1 Report on the Physical Science Basis of the Sixth Assessment.

Subscriptions to British Wildlife start from £35 – for more information or to subscribe, visit the website. Individual back issues are available to purchase through the NHBS website.


International Treaties in Nature Conservation: A UK Perspective
By David Stroud et al.
Paperback | Published May 2021 | £19.99

Read our interview with the author.



All prices correct at the time of this article’s publication. 

Wilding for Conservation: new series in British Wildlife

In a short space of time rewilding has grown to become a powerful force in conservation. The idea of giving nature the freedom and space to forge its own path is not just inspiring, but also raises deeper questions about our relationship with the natural world and how we best serve wildlife and ecosystems through a period of enormous challenge for conservation. To explore these and other aspects relating to rewilding, British Wildlife is launching a new series: Wilding for Conservation. The series started with two articles in the February issue, along with an editorial in which Series Editor Rob Fuller and BW Editor Guy Freeman explain how they hope to contribute to the discussion on rewilding and its role in conservation in Britain. An abridged and edited version of the editorial is included below.

The February issue of British Wildlife

Letting nature take back control

Deceptively simple in essence, rewilding resonates with something latent in many of us – a longing for a wilder world. It has captured the imaginations not only of conservationists, but also of landowners, policy-makers and, especially heartening, many young people too. Enthusiasm abounds for the idea that natural processes can be harnessed as solutions to some of our biggest environmental challenges, including climate change and biodiversity loss. Rewilding has rapidly become a central element in this ‘new’ thinking, with many believing that it offers a fresh start for what they see as an ineffective conservation movement presiding over catastrophic declines in nature. But what exactly is rewilding, and what is it not?

Rewilding emerged in the 1990s as a predominantly North American movement, but became strongly embedded in British conservation consciousness somewhat later, partly aided by the publicity surrounding several pioneering projects, such as Oostvaardersplassen, Ennerdale and Knepp. The publication of Feral by George Monbiot in 2013 undoubtedly also helped to fuel interest. In a remarkably short period of time, rewilding has spawned several conferences, bewildering numbers of papers and articles, several influential books and new organisations, notably Rewilding Europe and Rewilding Britain, founded in 2011 and 2015, respectively.

Interpretations of exactly what rewilding means have proliferated and often ranged far from the original concept. Most advocates, however, would seem to argue that it embraces natural processes without defined outcomes, and ideally operates over large tracts of land. In Britain at least, the enthusiasm for rewilding has met with some scepticism, even among conservationists, which may reflect disquiet about the absence of targets, a perceived threat to what has been achieved in the past, or simply confusion over what all the noise is about. One can legitimately ask whether the ideas are actually new or novel. Approaches guided by natural processes were being promoted long before rewilding became mainstream, while the merits of non-intervention versus habitat management have been discussed for decades in British conservation circles. What distinguishes the rewilding ideas that emerged in North America, however, is their focus on wild land on a grand scale, allowing the unhindered movement of animals, including large predators and their prey.

Discussions of rewilding in more heavily modified European landscapes quickly become entwined with questions of what can be classed as ‘natural’, the extent to which we should attempt to re-create historic environments, and the desirability and ethics of using species introductions to try to replicate processes that existed in the past as opposed to allowing ecosystems to develop a new kind of naturalness. Working to create wilder places for both people and nature is an admirable direction for conservation in Britain, but, given the constraints and small scale of many initiatives, ‘wilding’ perhaps captures their essence better than rewilding could.

Existing conservation approaches have not been able to prevent widespread declines in biodiversity over recent decades, although without them things could have been far worse. Some argue that rewilding (or wilding) is a way to set nature on a better course in our islands, but how can we be sure of this? There are severe limitations on land availability for conservation, especially in the lowlands, and the benefits from rewilding may not become apparent for many years. Are we approaching a point at which we need to rethink what kind of nature and wildlife we want?

British Wildlife has effectively been contributing to the ‘wilding debate’ through articles going back to a time when the ‘R word’ was unheard of on this side of the Atlantic. Notable early contributions include two from 1995, one vigorously challenging priorities in British conservation and arguing that greater attention be paid to more natural vegetation, and a second far-sighted article which echoes this from a different perspective and reads like a blueprint for much contemporary wilding. A special issue in 2009 was something of a milestone, containing a set of articles on naturalistic grazing and rewilding, stimulated by Frans Vera’s ideas about how large herbivores shaped pre-Neolithic landscapes. Topics tackled more recently include the nature of past landscapes, the definition of naturalness itself, reintroductions, natural regeneration of woodland and wilding in farmland landscapes.

Over the coming months, British Wildlife will be exploring the many facets of rewilding as they relate to conservation in Britain through a new series, ‘Wilding for Conservation’, a title which, we hope, captures the wide range of approaches to letting nature take back control. We start things off in the February issue with two pieces, one expounding a pure approach to rewilding , the other looking at relationships between traditional conservation management and rewilding . The series will examine some of the questions about rewilding raised in this editorial and bring ideas contained within the expanding scientific and cultural literature to a wider audience, while providing examples of what is happening on the ground in the UK and elsewhere. We hope that readers find the series to be thought-provoking and inspiring.

Articles in the Wilding for Conservation series will appear intermittently through 2021 and beyond. Individual copies of the February issue of British Wildlife are available to buy through the NHBS website, while annual subscriptions start from just £35 – sign up online here.

BES Summer School Guest Blog: Part Two

This post continues the series of guest blogs written by students from the BES Undergraduate Summer School 2020. In this, the second installment,  Kira Prouse discusses the gases responsible for the smell of the sea and their role in marine ecosystems.

Kira Prouse

How plankton are responsible for the smell of the sea

The smell of the seaside is distinctive and elicits nostalgic memories for many people. It may be a surprise when you learn this charismatic smell is actually made up of a cocktail of gasses from phytoplankton and bacteria in the ocean’s surface waters! The smelliest of these gasses is Dimethyl Sulphide.

Dimethyl Sulphide, shortened to DMS, starts as DMSP or Dimethylsulfoniopropionate (a bit of a tongue twister!) and is broken down into DMS when the cell containing it dies, and the chemical is released into the water column. DMSP is thought to help with:

• Allowing cellular reactions to continue in polar regions with freezing conditions.
• It acts as a natural sunscreen, protecting against harmful chemicals produced by high light or ultraviolet radiation.
• It allows for survival in saline oceans by regulating DMSP concentrations to match the salinity of the surrounding environment.
• Herbivore deterrent – DMSP and DMS may be produced by algae to make them herbivore deterrents and reducing grazing damage.

Photo by Fer Nando via Unsplash

Many animals, including birds, turtles and marine mammals, use the smell of DMS in order to find areas rich in food. In an otherwise vast and featureless ocean, the scent of DMS could hint at bathymetric features like upwelling zones and seamounts (areas known for their high productivity). As DMS is released when the cell dies, this could happen when the algae or phytoplankton are grazed by zooplankton, which would appeal to animals such as albatrosses who have a very good sense of smell. Unfortunately, as plastics are continually polluting the oceans, DMS particles cling to the surface of the plastic and make it smell appealing to any animal attracted to the scent of DMS. This means more plastic is being injested by birds because it smells like a tasty meal.

Image by The Naked Scientists, 2014

Not only does DMS have an ecological benefit, it also has an impact on how the climate is regulated. DMS stimulates the formation of cloud seeding particles and thus the formation of clouds. DMS leaves the surface of the water where, in the atmosphere, it oxidises into a number of compounds including sulphur dioxide (a cloud condensation nuclei). These particles mix with the evaporated water from the ocean and form clouds. This is important because clouds play a role in the amount of solar radiation reaching the Earth’s surface. Some clouds reflect the solar radiation and prevent the rays reaching the surface, having a cooling effect. Other clouds trap heat from the Earth’s surface, having a warming effect.

The more we understand about DMS the better we will understand how climate is regulated and how it will be affected by climate change. There are still unanswered questions about why some algae produce more DMSP than others and whether this affects concentrations seasonally. This also means that concentrations could vary geographically too. To help find out, NERC are collaborating with The University of East Anglia to investigate DMSP in the English Channel over the span of a year.

This blog post was inspired by the Plymouth Marine Laboratories coffee break science series.

BES Summer School Guest Blog: Part One

This year, NHBS was proud to sponsor the BES Undergraduate Summer School.

This annual event is open to undergraduate students studying in their 1st or 2nd year at a UK or Irish university. The week-long programme provides training in a range of practical, ecological skills alongside networking events and career workshops.

Due to Covid-19 the 2020 Summer School was conducted online. As one of their tasks, students were asked to write a blog article on a subject of their choice. We are pleased to feature a number of their submissions here on the NHBS blog. The first, by Hannah Coburn, looks at the timing of breeding and migration in birds and how the changing climate can impact this.

Hannah Coburn

Changing Times

Phenology refers to the timing of key life events in organisms, which play an important part in every species’ ecology [1]. The phenology of birds, including the timing of breeding and migration, is a well-studied field due to its popularity and ease with which it can be studied [2]. Many bird species have evolved to court, nest, mate and, in some cases, migrate at precise times of the year, in order to coincide with ideal conditions and the height of availability of crucial food sources [1]. However, the changing climate is beginning to disrupt these intricate balances.

Different organisms are acclimatising at different rates to the changing climatic conditions, and this dissonance can be catastrophic for breeding birds, particularly migratory species [3]. For example, if trees begin to produce leaves earlier, the invertebrates that feed on their leaves begin to emerge sooner, and if birds relying on these invertebrates do not lay their eggs earlier in the season, they may miss the peak of the insect abundance and be unable to feed their chicks [1].

Figure by Hannah Coburn. Caterpillar image:, Blue Tit image: RSPB.

The loss of synchrony between the phenology of birds and the species they interact with is already having a variety of consequences. A study in the Netherlands examining the potential impact of climate change on two woodland bird species [3] found that Great Tits, a resident species, respond to temperature changes faster than Pied Flycatchers, a migratory species. This is due to the Tits being able to respond to local temperatures and food availability while the Flycatchers are restricted by the time at which they arrive in spring. It was also predicted that migratory birds may suffer as a result of heightened interspecific competition caused by higher numbers of resident birds surviving milder winters.

Some bird species have already been proven to have advanced the times at which they migrate, in response to increasing global temperatures. A large study of migration data from European and North American bird observatories [4] discovered that birds now migrate on average a week earlier than they did in the late 1950s. While some birds have remained relatively consistent in the times in which they migrate, some species such as the Goldeneye, a diving duck, are now migrating as much as two weeks earlier than they did just forty years ago. Juvenile birds, under less pressure to reproduce, showed little change in migration timing. Another study [5] that analysed global migration data covering almost three centuries and over 400 species found that, on average, birds had migrated two days earlier (in spring) per decade and 1.2 days per degree (Celcius) of global temperature rise. They also noted that generalist species had responded faster to climatic shifts than species that had more specialist niches.

Image by Hannah Coburn

Even in my home town, I have noticed migrants such as Swallows and Swifts arrive earlier and earlier. Is it because the birds migrate in response to certain temperatures, which are coming earlier in the season? Is it because individuals that migrate sooner are now more likely to survive and so this trait or behaviour is becoming more common? We are yet to uncover all the intricacies of bird migration. Like any other aspect of biology affected by climate change, it is the species that adapt fastest that will survive. Sadly, if we fail to prevent runaway climate change, the birds that are unable to synchronise their phenology to the new normal may be lost forever.


  1. Rubenstein, M. (2017). When timing is everything: migratory bird phenology in a changing climate. S. Geographical Survey.
  2. Gordo, O. & Sanz, J. J. (2006). Climate change and bird phenology: a long-term study in the Iberian Peninsula. Global Change Biology.
  3. Samplonius, J. M. & Both, C. (2019). Climate Change May Affect Fatal Competition between Two Bird Species. Current Biology, 29(2):327-331.
  4. Learn, J R. (2019). Climate change has birds migrating earlier. The Wildlife Society.
  5. Usui, T., Butchart, S. H. M. & Phillimore, A. B. (2016). Temporal shifts and temperature sensitivity of avian spring migratory phenology: a phylogenetic meta?analysis. Journal of Animal Ecology, 86(2).


British wildlife in lockdown

Long-tailed Tit was a new species for Michael Scott’s garden, in north-west Scotland. Michael Scott

This is an extended version of an article, ‘British wildlife in lockdown’, that appears in the June issue of British Wildlife

Amid the enduring difficulties of the COVID-19 pandemic, it has been heartening to see the resourcefulness, resilience and imagination shown by the naturalist community. To give a taste of this, we asked our British Wildlife contributors how they had spent their time through late March and April, when restrictions were at their tightest. Here we give you the delightfully varied responses that came back. I hope that readers enjoy this snapshot of life in lockdown for the naturalist.

A spectacular spring

The start of lockdown coincided with a most exceptional run of fine spring weather (April was duly confirmed by the Met Office as the sunniest since 1921). While it was somewhat torturous to watch this unfold from the confines of our homes, time outdoors was all the more invigorating for it and the usual spring arrivals and emergences were met with even greater joy than normal.

A number of our regulars have tracked the changes as spring progressed, and Simon Leach has been encouraging local recorders to do the same: ‘I’ve been recording first flowerings since 2008 in the Taunton area, replicating (sort of) a similar exercise undertaken by Walter Watson in the first half of the twentieth century. And this year, constrained by “lockdown”, it seemed like a good idea to “widen the net” to get others in Somerset recording first flowering dates as well.’ By late May more than 35 participants had been drawn to the cause, and their recording from the height of lockdown through to the time of writing, in late May, has highlighted an extraordinarily early spring: Common Dog-violet Viola riviniana, Greater Butterfly-orchid Platanthera chlorantha and Biting Stonecrop Sedum acre, for example, have all had their earliest first flowering dates since Simon started the initiative.

Spring seemed to arrive early farther north, too, as Michael Scott notes: ‘Lockdown in the northwest Highlands is not too different from normal life here, but with few tourists and without the incessant afternoon hum from the rush hours of transatlantic jets. April 17th was a red-letter day. As I ate breakfast, I spotted the first Swallow of the year. Going outside, I heard the first Cuckoo from the adjacent hill. Later, a distinctive off-key scolding from the coastal bay below the house told us that the Common Sandpipers were back, too. They were respectively one, four and two days earlier than we recorded last year, but I suspect that may just reflect more observer effort!’

And it was not just summer migrants and wildflowers that were making early appearances, but also spring invertebrates. David Christie, copy checker for BW, noted the following from his home in Southampton: ‘Among the highlights were the garden’s earliest ever Dark-edged Bee-fly, on 16th March, a pleasant sunny day which also produced a Comma, a Small Tortoiseshell and two Brimstones. On 26th, an astonishing addition was a single male Wood White, unsurprisingly the first ever for the garden — but some 6 weeks too early! I imagine that this, the daintiest of the whites, was bred and released by somebody nearby (several people have released butterflies in the area in previous years). In April Orange-tips became the commonest butterfly, and on 16th of that month a Red-tailed Bumblebee, supposedly a common species but a garden first, turned up; it stayed for several days but had apparently disappeared by the middle of the following week.’

Orange-tip butterfly on Lady’s Smock.

Peter Marren has enjoyed tracking changes on his local patch in Ramsbury, Wiltshire: ‘The sunniest side of this enforced lockdown is that I have come to appreciate home turf as never before. It helps that this has been the brightest, if not the warmest, April for some time, but this year the beauty of the meadows, woods and downs around Ramsbury has made me gasp, as if seeing it for the first time. I watched while a late spring turned into an early one. Frog spawn, flocculent and chilly, appeared in the ditch outside during the first week in March, and by the second week in April the tadpoles were already well grown. I heard the first Chiffchaff, much later than usual, on March 18th. It was joined in song by a Blackcap by March 25th. I heard the first Willow Warbler on April 5th (they are still doing well here, and have spread from the valley scrub into a belt of trees below the down, planted 15 years ago). The first Orange-tip fluttered into my garden on 9th April. The first singing Reed Warbler began –like a cold engine warming up – on the 10th, I spotted the first Swallow on the 13th and heard a solitary Cuckoo calling from the reedbed on Easter Sunday, 12th April. There was a close tie-in this year with the opening of our two cuckoo flowers, Lady’s Smock Cardamine pratensis and Lords-and-Ladies Arum maculatum. I should perhaps mention that spring usually comes late to Ramsbury. We are in a narrow east-west valley where a cold westerly blows from the Marlborough Downs and puts everything back by about a week.

‘Apart from the perennially exciting arrival of our summer visitors, I find I am looking at the small, easily overlooked things in life. This year I watched the leaves unfurl. Ash has, for once, tied with oak (so perhaps we are in for neither a splash nor a soak). Its feathery leaves push upwards in a shuttlecock from a bush of spent flowers, then angle out stiffly on their long petioles. By contrast, the leaves of oak curl softly from their buds, masked by a screen of yellow-green catkins. For a day or two, the hedgerow oaks take on an almost autumnal hue before they turn spring-green, that delicate, tender green that lifts the heart and makes you feel young again (anyone know any good oak songs?). Baby oak leaves lack the bitter tannins that build up later on. I nibble some straight from the branch – green chewing gum. Isolation makes you do strange things.

‘I’m also looking at bees. The only way I can get close to a bee is with close-up binoculars. Where banks face the sun, and especially when they are sheltered by a hedge, the mining bees are busy, locating their little, barely visible excavations, and vanishing into them bearing heavy loads of bright yellow pollen. Much of it, I note, is taken from Leylandii cones (so let’s hear it for once for that much-maligned conifer). Watching the bees at work are a whole host of parasites. On 31st March there was a brief flurry of oil beetles. Later on, nomad bees and blood bees were swarming about, each intent on laying a single egg inside the mining bee’s chamber. Patrolling bee-flies will do the same. The proper bees do not seem to notice that they are surrounded by malevolent cuckoos. Imagine a troop of hostile visitors raiding your cupboards and your fridge, sleeping in your bed, chasing away the kids. And that’s before the insecticides get you. I am glad I am not a bee. I am glad I live in Ramsbury. The swamp may be muddy yet – for the valley has taken a long time to recover from February’s floods – but it is full of life. Nature is the perfect antidote to despair in this surreal, locked-down spring.’

A number of correspondents noted what an excellent spring it has been for invertebrates, and bees in particular seem to have been popular with those wishing to use their time in lockdown to get to grips with a new group. From Anglesey, James Robertson writes: ‘I sit on a low wall, dangling my legs. After a while a queen Garden Bumblebee heads into a gap at the base of the wall by my feet. I am learning the skill my ornithologist brother tried to teach me many years ago. Then I was having none of it. Plants sat around on their bottoms, I had to search them out, keep on the move. But this year everything is different. Be still and the insects come to you. As so often, the constraints we are under force us to be creative, to learn new tricks and look at the world afresh.

Buff-tailed Bumblebee.

‘As the dominant hominid falls silent, nature booms and buzzes. The exceptional weather puts on a display of insect variety. Wasp Beetles bounce around my garden, flicking their antennae and not looking quite right for the wasps they pretend to be. Red Mason Bees investigate holes in concrete posts and Joanna’s Bee Hotel, a future bee smorgasbord for hungry Blue Tits. She has quickly mastered the identification of Early, Garden, Red-tailed and Buff-tailed Bumblebees.

‘My car windscreen is splattered with insect bodies. This is supposed to be a memory, how it was when we were children. Is this explosion of life a sign of what would happen if we stilled the great machine of our industrious world?’

It was not the abundance of bees but a single unexpected one that provided a highlight for our copy editor, David Hawkins: ‘I was delighted when a rather smart solitary bee appeared in my flat in Bristol, having blundered in through the window. I consulted Falk & Lewington at length, but was perplexed – trying my damnedest to make it an Andrena of some sort, although none of the candidates looked quite right. Plus it had very beautiful mottled dark blue-grey eyes. Then, using a hand lens, I caught sight of a small spike on the underside of the first sternite – this, apparently, is diagnostic of a male Spined Mason Bee Osmia spinulosa. It seemed very curious to encounter it in the middle of the city, but we live near a railway line and some allotments so there may well be suitable habitats there. Most interestingly, as with some other Osmia spp., it nests inside vacant snail shells.’

While lockdown may have produced a new generation of bee enthusiasts, it was perhaps not such a good time to pick up an interest in flies. Alan Stubbs reports that his garden ‘is almost bereft of hoverflies; yesterday I achieved the fourth species for the March–April period and I have never seen more than two of any on a lap of the garden. Flies as a whole are very sparse even now (23rd April), a shame in the lockdown. The current drought does not help, but there is a legacy effect from low populations and drought last year. The excessive winter rains have not been of benefit (and have possibly been a negative factor). Currently it is difficult to know how widespread the doldrums extend, but I suspect areas that have had more rain over the last four to six weeks will have fared a bit better. Reports from London and Warwickshire suggest I am not alone.’

Bringing wildlife to you

While opportunities to go out into the wider countryside were limited, many found ways to bring wildlife to their doorsteps instead. Moth-trapping has seen a surge in popularity, as Paul Waring explains: ‘Moth-trap operators are better placed than many wildlife enthusiasts to cope with lockdown arrangements. Most of us routinely operate a light-trap in our gardens, and some do so on verandas and roof-tops if they have no garden. With a light-trap the moths come to us, from the garden itself, and from beyond it, so we do not need to leave our home to record what is about. The numbers and variety of moths in the catch and the seasonal patterns of occurrence always hold some interest, even in inner city locations. One is sometimes amazed at what turns up. Facebook has been full of people reporting their garden catches, often including photos of the moths, sometimes with lively discussion, throughout the lockdown period.’

This pre-pupal Purple Hairstreak larva was found by chance when the photographer noticed it among empty Hazel nuts that his son had collected. Wren Franklin

The staff at Butterfly Conservation, unable to get out into the field, have also focused on moths in their gardens. Mark Parsons tells of some early highlights: ‘During lockdown the conservation staff at Butterfly Conservation were encouraged to run a moth trap at their homes. At least 28 staff participated, with traps being run from Devon to Cambridgeshire and north to Deeside, as well as in Northern Ireland. Although there were a few cool evenings in the first three weeks, generally conditions were relatively mild and very suitable, and as a result there were a lot of interesting observations. Of the scarcer species there were records of Silver Cloud Egira conspicillaris (Worcestershire), Small Eggar Eriogaster lanestris (Dorset), Marbled Pug Eupithecia irriguata (Devon) and the micro-moth Mompha divisella (Dorset and Glamorgan), with a Light Orange Underwing Boudinotiana notha (Surrey) being seen by day. Other interesting records included high counts of Lunar Marbled Brown Drymonia ruficornis (56) and Frosted Green Polyploca ridens (31), both on 11th April in Surrey. It really is amazing what can be found in gardens!’

A pair of Tawny Owls was captured by camera trap while bathing in the river behind Andrew Branson’s garden. Andrew Branson

BW’s Founding Editor, Andrew Branson, has been making good use of other technologies to monitor goings-on in his garden: ‘So often when we are observing the natural world we are looking at it from a very narrow perspective both in time and in space. We return to our favourite haunts looking for confirmation of the same species – the anxious scanning for returning migrants is a classic expression of this. I am always struck by the way we have a mental search pattern that reinforces what we expect to see. A classic is the way botanists with their stooping gaze on the ground will often fail to record unusual tree species right above them. In lockdown I have been trying to extend my appreciation of garden species by using a webcam to record nocturnal life. I’m lucky enough to have a garden that reaches down to a river, and have been discovering that not only do we have the expected Brown Rats, Mallards and Moorhens making regular nightly visits, but our garden also seems to be on the rounds of an Otter, an American Mink (not so welcome), Hedgehogs (first I’ve seen in the garden for years), Roe Deer, Foxes and Rabbits. Recently, the webcam captured a furtive pair of Tawny Owls having a midnight bath in the river!’

Dave Wilkinson has spent time studying some of the more obscure lifeforms in his pond: ‘Lockdown natural history: in the imagination it is snow leopards and camels as I read George Schaller’s new book Into wild Mongolia, while in reality it’s restricted to the garden and occasional short walks. In February we had a new garden pond dug, with the first water plants going in just before lockdown. With few ponds nearby it quickly attracted birds, hedgehogs and wasps; to drink, wash, or forage along the edge. Water beetles, pond skaters and water boatmen quickly followed. New ponds tend to be prone to algal blooms and ours is no exception. The torrential rains of February washed surrounding soil into the newly dug pond, adding nutrients, then the warm sunny weather of April powered algal photosynthesis – the pond first scummed with ‘blanket weed’, then turned bright green with cyanobacteria and other algae. Without lab access (no plankton net or centrifuge) some ingenuity allowed me to concentrate some plankton to view with a rather basic 50-year-old microscope. With such equipment colonial cyanobacteria – such as Aphanocaspa – were easier to isolate than smaller cells. The floating ‘blanket weed’ quickly vanished, but small patches of filamentous algae are in the shallows, including the green alga Stigeoclanium. Under the microscope these threads have the look of cells-within-cells, with small round green structures within the longer tubular cells. These structures are chloroplasts, the site of photosynthesis with the product stored as starch, staining dark when I added iodine. Back in the depths of geological time these chloroplasts evolved from free-living cyanobacteria; down my microscope I am seeing the history of our emerald planet encapsulated in the green scum of a garden pond.’

And in the terrestrial realm, Roy Watling has also been looking at some smaller organisms in his garden in Edinburgh: ‘Some years previously, when I was recovering from a medical procedure, I had to make time for exercise. I walked around the streets close to my house, gradually increasing the distance each day; I could not resist the temptation to “mycologise” though and began to list all the micro-fungi found on the vascular plant cultivars I saw in each garden. Now I am confined to my own garden because of lockdown I decided to conduct a similar survey, with surprising (to me at least) results. Thus, the tips of shoots of Irish Tutsan Hypericum pseudohenryi hosted the mildew Erysiphe hyperici, which is not uncommon on our native plants, while hidden among the erect branches of the snowberry Symphoriocarps x doorenbosii was another mildew, E. symphoricarpi. These two species are not rare but are poorly recorded in Scotland, and certainly neither has previously been recorded here on these hosts. The true mould Ampelomyces quisqualis, a parasite of a range of mildews, is equally under-recorded, although can be obvious to the keen observer. Also evident in my border was blotching on the shrub Hebe x francisciana: a rather distressing sight caused by the fungus Septoria exotica. On the north facing side of the house where it is moist and shaded, Chaetothyrium babingtonii grows prolifically in a mixed planting of various Rhododendron cultivars and hybrids. This fungus is common and widespread under the right conditions, and although it does not appear to harm the plants it looks very unsightly – thank heavens it only occurs on Rhododendron!’

Grass Snake swimming in a pond.

Frances Dipper has been observing the interactions between some more familiar species: ‘The human brain is much better than a computer algorithm at picking out patterns (hence ‘Galaxy Zoo’ – the web-based project that uses citizen scientists to classify distant galaxies based on their shape) so changing from recording fish (and other marine life) to birds and garden wildlife is proving to be a fascinating experience during lockdown. Seashore recording and diving are time-limited, but looking out at a habitat resource (i.e. the bird feeders in my large, wildlife-friendly garden) is not. As a marine biologist learning to be an ornithologist, here are some recent observations. Some Greenfinch Carduelis chloris prefer to spray out sunflower hearts from the feeder and then eat at their leisure on the ground below – memories of rich arable field pickings? Much smaller Goldfinch Carduelis carduelis will hold their ground (perch) on the feeder in the face of Greenfinch bully tactics. Starling Sturnus vulgaris are now adept at clinging on to feeders – perhaps our Cambridge ones are fast learners. Great Tit Parus major will nest in vertical holes, in this case a hollow brick column. There is also a Magpie Pica pica nest in our oak tree. A faithful Spotted Flycatcher Muscicapa striata pair used to nest every year in the same vine until a Magpie raided its nest a few years ago. The best sighting to date? Not a bird but a Grass Snake Natrix natrix swimming across the pond and obviously unaware that Great Crested Newt Triturus cristatus is a protected species! Now how did one of the latter get into my downstairs shower room?’

And the extra time at home allowed Michael Scott the chance to notice garden visitors who might have gone undetected in a normal year: ‘Freedom from urgent deadlines has meant more time to observe how regularly a pair of Yellowhammers come to join the Dunnocks and an occasional fat Bank Vole feeding on the grain that ungrateful Chaffinches and House Sparrows regularly scatter onto the ground from our bird feeders. A small group of Long-tailed Tits in early April was a first for the garden. One was collecting the frayed ends of some garden string, presumably for a nest somewhere in the area.’

David Christie noted some apparent effects of the lockdown itself on the birds in his garden: ‘Perhaps the most notable feature of April–May was that many birds were becoming unusually tame. When I was “tidying” a corner of the garden, an adult female Blackbird walked around my feet, picking up odd items of food; feeding within a few centimetres of my feet, she occasionally looked up at me to check what I was doing! The visiting Stock Doves, too, were tamer than usual. On 24th April, a pair of Blackcaps had begun nest-building just a metre from our back window; although several Blackcaps regularly spend January–April in the area, they have never before nested here (sadly, the pair deserted at the laying stage). By the end of the month, a Blackbird pair with three fledglings showed no fear of humans, nor did a fully independent young Robin.’

Contributors reported some wonderfully serendipitous sightings to have emerged during lockdown. This Buzzard was found and rescued having got itself firmly stuck in a Rabbit hole. Rachel Barron-Clark

And Hugh Raven similarly has been musing on the possible effects of lockdown on the wildlife of his local loch and beyond: ‘Float over the deep belly of our local sealoch and look north, and you spy two rivers as they reach the sea – in plan like the outstretched arms of a mermaid’s purse. Embraced by these limbs is a verdant turf of saltmarsh fringed by a pancake of sandy mud, twice daily exposed when the tide recedes. At this time of year, it’s the haunt of sawbills. Goosanders and mergansers are by nature shy and flighty, but this year they are abundant. With human traffic around the loch and up these rivers – never heavy – a fraction of the norm, having eaten their fill they laze about on foreshore and saltmarsh preening in the spring sunshine. I counted 18 one day in late April. Sawbills are good at fishing. Research from Norway reports “adult goosander on average eat from 310 to 500g fish a day”. At this time of year they’re enjoying the feeding opportunities presented by the smolt run – that evolutionary miracle that sees juvenile salmon pour downstream as maturity, light and temperature tell them to reset their osmotic meter, leave fresh water and start to fatten up in their marine phase.

‘Salmon smolts weigh some 20g, so if they are the main source of food, each duck may eat twenty or more a day. Thousands will disappear down their gullets. The local river is noted for the freshwater pearl mussel – which depends on migratory salmonids to survive. You can get a licence to shoot sawbills, but there’s no appetite for that here. Salmon and pearl mussels, or these beautiful sleek and shiny ducks? Such are the dilemmas of conservation.’

Natural history online

The lockdown experience would surely have been very different had it happened in the not-so-distant past. Social media, and the online world in general, has changed our hobby and helped naturalists to stay connected throughout this period (see Brett Westwood’s column in this issue for more on this topic). Members of the birding community, for example, have been enjoying the rapid sharing of news, and a healthy element of competition, while working on their ‘lockdown lists’.

White-tailed Eagles have provided some excitement during lockdown; many sightings across England involved juveniles from the Isle of Wight reintroduction project, but the pictured individual, seen in Buckinghamshire, was unringed. Dan Forder

Dawn Balmer reports: ‘The movements of the released White-tailed Eagles from the Isle of Wight have been well tracked by the birdwatchers fortunate enough to spot them flying over their gardens (see I’ve also been amazed how many people have recorded Osprey over their garden, too! Both species seemed to have avoided airspace over our garden, though we were lucky enough to see two Cranes circling overhead on 20th May.

‘The first few nights of April saw a large passage of Common Scoters overland. While not a new phenomenon, it has never been documented so well. Birders stood in gardens and listened in the dark, others set recorders to record overnight – see for a summary. Personally, we sat outside in our garden in Thetford (Norfolk) on the nights of 1st and 2nd April and heard Teal and Wigeon on the 1st, and Wigeon again on the 2nd. We’ve since added Moorhen to our house list – heard one fly over calling at 3.45am, and Dunlin, which flew over calling at 10.30pm one evening! With a bit more time on people’s hands, more have taken up “nocturnal migration” recording.’

Adrian Knowles has been monitoring the Facebook pages of the Essex Field Club, which has produced some notable records through lockdown: ‘Rob Smith posted a picture of the fly Bibio venosus from his daily walk patch, Headley Common in south Essex. Apparently there are only two other records in Essex, both in the north of the county. He has also recorded the mining bee Andrena cineraria from the same site – this species remains a scarce in Essex. There were two records of the ladybird Rhyzobius forestieri, a recent colonist of the UK, including one in someone’s garden. Then, on 10th April, Ed Hardy grabbed a load of wood chip during his morning walk with a view to identifying contents during his lockdown time. His finds included the beetle Rugilus angustatus, which is rare in the county, with a lack of recent records.’

Martin Harvey, David Roy and Helen Roy offer some insight into the effect of lockdown on submissions to iRecord, the online biological recording system maintained by the Biological Records Centre (part of the UK Centre for Ecology & Hydrology): ‘April 2020 proved to be a busy month with over 100,000 records added, up from about 75,000 in April 2019. It’s hard to know how much of this increase is the result of people taking up wildlife recording as an activity while locked down close to home, and how much is due to the combination of overall growth in records arriving at iRecord and the sunny weather that many experienced during April. But there do seem to be some changes in the patterns within these records. Not all biological records state the habitat that they were recorded in, but for those that do there has been a clear shift, with the proportion of records assigned to gardens more or less doubling, and a big fall in the number of records assigned to “wilder” habitats such as woodlands and grasslands. The most frequently recorded species during the month have been typical garden visitors, including butterflies such as Orange-tip and Peacock, the Dark-edged Bee-fly, Hebrew Character moth and Buff-tailed Bumblebee.’

‘Records arriving in iRecord are checked and verified by expert naturalists on behalf of the national recording schemes. An impressive three-fold increase in verification during April 2020 compared to the previous year is testament to the dedication of these people, and no doubt also demonstrates they have been making good use of the time that might have been spent in the field during a different year.

‘What effect these changes will have on the total pool of records available for 2020 remains to be seen, but it will be exciting to consider the ways in which these records can contribute to the long-term analyses that BRC and the recording schemes collaborate on. In the meantime, we hope that as many people as possible have been able to find ways of connecting with nature during these unprecedented circumstances.’

Butterfly Conservation has encouraged people to track species undergoing range expansions; during lockdown, a Comma was reported at Dunnet Head – its most northerly ever location in Britain. Edith Jones

The lockdown has provided an excellent opportunity to fill in gaps in distribution maps and monitor species on the move by encouraging the submission of records. Butterfly Conservation, for example, is asking the public to report on butterflies seen in their gardens, as Caroline Bulman explains: ‘Understanding the changes in patterns of emergence and distribution across the UK is vital to improving our understanding of the impacts of climate change on butterflies and other native wildlife. Wherever you live your observations are even more vital this year and particularly those in northern England and in Scotland, where you can record novel information of species which are spreading northwards, in response to a changing climate. For example, in mid-April we had a report of the most northerly Comma ever recorded in Britain, found in Caithness on the north coast of Scotland! If you’d like to get involved go to to register and download a free smartphone app, or sign up to record butterflies in your garden, on your PC or laptop at where you can also read the results from 2019.’

Paul Waring used the daily exercise walks to further the understanding of moth populations in his local area: ‘During lockdown we have taken the opportunity of beating for caterpillars to start recording the colonisation by moths of a hedgerow of various native broadleaf trees newly planted to screen from view a field of solar panels. We have also carried our pheromone lure for Emperor moths Saturnia pavonia with us every day to see if the large “white hole” for this species shown just south of The Wash in the newly published Atlas of Britain and Ireland’s Larger Moths reflects lack of recording or a genuine absence. Thus far it appears the Emperor really is absent, although this is certainly not the case for many other moth species for which there is a similar white hole.’

For some groups, recording need not be limited to our time outside the house either. Geoff Oxford writes: ‘The British Arachnological Society, working with Jordan Cuff (Cardiff University), has launched two “lockdown” spider surveys that can be completed around the house and garden. One is to record the species, numbers and locations of the three British cellar spiders –the very common Daddy-long-legs Spider Pholcus phalangioides, the much less common Wine Cellar Spider Psilochorus simoni and the rare Marbled Cellar Spider Holocnemus pluchei. The second, newly launched, is to record when clusters of Garden Spider Araneus diadematus spiderlings are first noticed. Details of both surveys can be found on Twitter @BASSurveys and at Response so far to the first survey has been good with some 50 people counting a total of over 185 cellar spiders, some in previously unrecorded hectads.

‘The lockdown has not seen arachnologists locking away their equipment. Initiated by Richard Wilson and Chris Cathrine, naturalists nationwide have taken to surveying their garden lawns in a two-minute sample using modified garden blow-vacs. Early results include a new spider for Yorkshire, Cryptachaea blattea. The survey has led to informed discussion via Twitter @britishspiders and #lockdownsuckschallenge, creating a forum for promoting more widely spider biodiversity in gardens. Lockdown has seen an unprecedented surge in interest in arachnids more generally; we have been inundated on Twitter.’

Examination of old material produced a record of Caloplaca aractina (the grey lichen) from Muck, in the Inner Hebrides – a remarkable range extension for a species previously thought to be restricted to The Lizard, in Cornwall. John Douglass

Lichenologists, too, have been getting better acquainted with their home patches, with some excellent results – Sandy Coppins reports: ‘Lichens lend themselves to “local looking” perhaps more than several other wildlife groups. BLS Twitter suggested recording lichens on your doorstep, window sill or garden, etc. But after your initial ten lichens seen on your patio slabs, where to go next? Heather Paul, in Forres, says “I amused my neighbour by going down on my knees on the pavement outside to look at Lecanora muralis which of course I have never recorded here.” While in North Wales, Dave Lamacraft on a gentle potter to look at some nearby trees, “with a view to better learning some common things in ‘normal habitats’ for a change”, was surprised to find Ramalina lacera almost straight away swiftly followed by Schismatomma graphidioides – both pretty rare in Wales!

‘But perhaps the most surprisingly fruitful and fascinating lichen results from the lockdown came from not stepping out the door: John Douglass, in South Lanarkshire, for example, writes “I was sorting through some old boxes of specimens… and came across some C[aloplaca] aractina collected from a coastal rock face on Muck (2012). I have checked it against my collections from the Lizard and the spores etc. check out good for this species.” Apart from John’s Muck revelation, C. aractina is confined in the British Isles to coastal rocks at The Lizard, in Cornwall, so this find is a lovely disjunct extension.’

To conclude

As for the BW editorial team, while we have each been left slightly envious of those people with gardens we made the most of our daily exercise walks.

Female Hairy-footed Flower Bee. Catherine Mitson

Catherine Mitson, BW‘s Assistant Editor, reports: ‘Except in times of flooding, the Exwick spillway is a popular route for runners and cyclists alike. To one side, however, is a less frequently visited footpath that follows the natural flow of the River Exe. Here, the shrubs and trees grow a little more wild, and the tall bank to the right muffles the sound of passers-by. I can now enjoy the soundtrack of my walk, featuring the nasal ‘dzwee’ of Greenfinches, the chattering of Blackcaps, melodic Song Thrushes, and the drumming of a Great Spotted Woodpecker. This was the first time I had been here, despite living so close – a direct consequence of the lockdown. I now visit this small stretch almost every day and have seen the unmistakable flash of a Kingfisher, a Dipper on two occasions, and, looking up, there are often noisy Long-tailed Tits hopping around in the branches. During the last week of April, House and Sand Martins have arrived and are now regularly seen zipping across the river as the evening sets in. The first few sunny weeks of lockdown stirred many insects; of the butterflies I have spotted so far my personal favourites include Orange-tip, Common Blue, Peacock, Comma and Brimstone. My first Dark-edged Bee-fly of the year is always a personal highlight, but this was topped as I happened across a Hairy-footed Flower Bee nesting site in a cob wall less than five minutes from my house. These strange times have certainly opened my eyes to what lies just beyond my doorstep.’

Angular Crab found on Teignmouth beach. Guy Freeman

For myself (Guy Freeman), the lockdown highlights have come from strolls along my local beach here in Teignmouth which, naturally, have been timed to coincide with the best tides. The shore – mostly expanses of brick-red sand – does not look the most inspiring from a rock-pooling perspective, but I always enjoy the challenge of searching for life in these damp deserts. The walks during lockdown have been among the most productive I have had here, with favourite finds including some of the more weird and wonderful sand-dwelling specialists – the Angular Crab, which looks too exotic for these shores, and the more common but equally bizarre Masked Crab.

Many thanks to all the contributors to this piece who responded so enthusiastically to our initial call for submissions.

The contributors featured here write regularly for British Wildlife – the magazine for the modern naturalist

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Rewilding  provokes great debate among conservationists and the recently published book Wilding: The Return of Nature to an English Farm is likely to provide more fuel for future discussion.

British Wildlife editor Guy Freeman has sketched out the framework in which this debate takes place, and we have picked out some key books on this exciting new approach to nature conservation.


Rewilding – the process of returning land to nature – is rapidly gaining momentum. The concept itself is fairly simple, but its delivery is complicated by the question: ‘what exactly are we hoping to achieve?’ There is general agreement that rewilded landscapes should replicate those which existed before major human interference (i.e. prior to the development of farming during the Neolithic, around 6,000 years ago), but the significant point of contention comes when trying to establish what those landscapes looked like. The accepted view has long been that Britain became covered in a blanket of dense woodland – the ‘wildwood’ – as trees recolonised after the last glacial period.

This has been questioned however, and other theories have emerged, including one compelling alternative proposed by ecologist Frans Vera. Based on observations at the Oostvaardersplassen, a nature reserve in the Netherlands, Vera suggested that grazing animals would have dictated the distribution of different vegetation types and maintained a landscape that was far more open than previously thought.

This ongoing debate has important implications for rewilding and, in particular, the role that grazing animals should play. Based on the ‘wildwood’ or ‘closed-canopy hypothesis’, rewilding need entail little more than just leaving land untouched – Lady Park Wood, in Monmouthshire, provides a fascinating insight into how woodland develops without human intervention. Under Vera’s hypothesis, however, grazing animals need to be at the heart of the process – the Knepp Estate, in Sussex, is an impressive example of how nature responds when such an approach is taken.

Understanding historic vegetation patterns is important, and our knowledge is improving as analytical techniques develop and new strands of evidence are revealed. In reality, however, we will probably never know exactly what Early Holocene Britain was like, and we should not let the debate distract from the task at hand – in the many degraded parts of our landscape, any form of rewilding will be good news for nature.

Guy Freeman is the editor of British Wildlife  The Magazine for the Modern Naturalist


Further Reading

We have selected some further reading around the subject of Rewilding.  We suggest our top five below and you can click on the link to view our complete selection.

Feral: Rewilding the Land, Sea and Human Life
Paperback | June 2014
£7.99 £9.99



Wilding: The Return of Nature to an English Farm
Hardback | May 2018
£16.99 £19.99



Woodland Development: A Long-Term Study of Lady Park Wood
Paperback | Sept 2017


Trees, Forested Landscapes and Grazing Animals: A European Perspective on Woodlands and Grazed Treescapes
Paperback | June 2017


Rewilding European Landscapes
Paperback | Oct 2016



Browse all our suggested further reading for Rewilding.

Please note that prices in this article are correct at the time of posting (April 2018) and may change at any time.