James Aldred is an award-winning documentary wildlife cameraman and filmmaker. James has collaborated on numerous high-profile projects with Sir David Attenborough, including Life of Mammals, Planet Earth and Our Planet, resulting in several BAFTA/RTS nominations. He is also the author of The Man Who Climbs Trees.
In his latest book, Goshawk Summer, James details his extraordinary and unique experience documenting a family of goshawks in the New Forest during the national lockdown of 2020. We have had the very fortunate opportunity to ask James some questions
Could you tell us about how you first came to be interested in the natural world?
Through time spent outdoors in the New Forest, where I spent much of my childhood. My teenage obsession was tracking deer, particularly Red, which were quite scarce in the Forest during the 1980s. I also got into tree climbing at an early age. Many of my friends were training to be foresters and tree surgeons and they showed me how to use ropes to access the forest canopy. I immediately fell in love with this hard-to-reach, but wildlife-rich environment and regularly took my stills camera up with me to try and capture images of the New Forest from this unique perspective.
Travel restrictions due to the Covid-19 pandemic presented a unique opportunity to document nature with very little human interference. Do you think this period of time will have had any lasting impacts on the country’s wildlife?
Yes, but in a rather unforeseen way. The space provided by the initial lockdown period definitely helped those birds and animals with a shorter breeding cycle, but ultimately the lockdown period was too short to be of much lasting benefit to a lot of the larger wildlife, including large ground-nesting birds such as curlew. The levels of disturbance in the post-lockdown period were very high in some places and this had the unfortunate effect of causing problems for those species that had not yet completed their breeding season. Ironically though, these high levels of disturbance in the countryside in the immediate aftermath of lockdown may yet provide useful data in terms of how best to manage large visitor numbers in the future as our population increases to grow and national parks are placed under increased pressure.
To capture footage of the goshawks required time, patience and understanding, but your efforts were clearly rewarded. Do you have any particular highlights from your goshawk summer?
There were so many, but I think the nesting dynamics between an adult male and female were particularly fascinating. Their relationship was surprisingly complex, subtle and even-keeled for such a fiery bird. The male often covered the clutch to keep the eggs warm whilst the female fed off site, and was even allowed to feed the chicks himself on several occasions whilst the female stood by and looked on. Very unusual for Goshawk females to tolerate their mate being so close to the chicks like this.
For a young aspiring naturalist, a career as a wildlife photographer would seem to be an ideal choice, especially since our collective experience and knowledge is usually limited to what we see on film/television or on paper. Could you tell us a bit about the reality of what it’s like to be a wildlife cameraman?
The reality is very anti-social working hours, high levels of frustration and a huge impact on home life! But I wouldn’t change it for the world as it is undoubtedly one of the most soul-nourishing jobs you could ever hope to do, in my opinion. It’s a tough, highly competitive industry, but this doesn’t mean you can’t get in through gentle persistence and dedication. Knowledge is everything: read, watch and learn everything you possibly can about your chosen wildlife subject before even attempting to film it.
What’s next for you? Do you have any current or future projects planned?
I’m currently working on a large project commissioned by a popular US-based video-on-demand provider. I’ve just been filming in the Congo for them and due to head out to Borneo soon. I’m also working on an exciting UK-based project about rewilding, which is a subject I find particularly compelling and relevant. All the more so since it is UK based and has the potential to inspire the next generation of naturalists.
Lynx Edicions is a Barcelona-based publishing house known for their fantastic ornithology titles, alongside a varied collection of general natural history. Originally founded in 1989 to create the Handbook of the Birds of the World series, they have since expanded to over 150 titles, including field guides, monographs, and bird checklists. They continually produce exciting works, such as their most recent publication Seabirds: The New Identification Guide, a full, 600-page treatment of all known seabird species. NHBS is delighted to announce Lynx Edicions as our Publisher of the Month for August.
Throughout August we will have special offers on a selection of titles, giving you the perfect opportunity to explore their books. Browse a selection of highlights below, or Lynx’s entire range here.
Handbook of the Birds of the World (16-Volume Set + Special Volume) comprises all volumes of HBW, illustrating and describing in detail every species of bird in the world. This is the first work ever to illustrate and describe in detail every species of bird in the world, and also the first to verbally and visually portray each member of an entire Class of the Animal Kingdom.
An easy-to-use, fully-illustrated volume of all the birds of the world. Created for a broad audience, from novice birders to expert ornithologists and anyone interested in the spectacular diversity of birds, this fascinating book has something for everyone to discover.
This book represents the most up-to-date source of information on bird distribution and change in Europe, and is a great contribution to the global aim of understanding biodiversity to ensure its conservation.
This series of 9 large-format volumes describes and illustrates every currently recognised mammal species, and gives a detailed overview of each mammalian family. It provides up-to-date information on the evolutionary relationships, natural history, ecology, and current conservation status for all mammals.
This comprehensive field guide covers all of the birds and mammals known to occur in the Galapagos archipelago, providing the latest insights on field identification and taxonomy for challenging groups such as pelagic birds, Darwin’s finches, and cetaceans.
The first book to describe and illustrate every mammal species found in Madagascar. Also includes those of the nearby islands of Comoros, the Seychelles, Réunion and Mauritius.
All prices correct at the time of this article’s publication.
A Trillion Trees is an optimistic take on the future of the world’s forests, with Fred Pearce believing that the damage humanity has inflicted can be undone, so long as nature is allowed space to recover. The book opens with an introduction to the myth and magic of forests. Through describing a botanical explorer’s conservation of orchids in the rainforests of Ecuador, recounting one of the author’s most memorable forest experiences (getting lost in a wood on the North Downs as a child), and presenting the varied reactions of early European explorers to the rainforests of the tropics, Pearce laments the loss of ‘primaeval wildness’ and the untouched forests of those times.
Since 1992, Pearce has been writing for New Scientist magazine on the importance of trees, as well as their ownership, uses, protection, and destruction. He has spent his career contributing to multiple well-known publications, writing a range of books, and speaking on environmental issues such as carbon emissions, invasive species, and climate change. Despite forty years of continued reporting on global environmental issues, he maintains optimism for the future and for forest regrowth.
Pearce’s enthusiasm and respect for trees is clear throughout. This book celebrates trees, exploring their importance and the impact they have on the climate, the history of how our relationship with forests has changed, the recovery that is already taking place, and the future role of trees in an emerging community-centred approach to the land. Pearce intersperses topics on the politicisation of forest and climate research, the impacts of deforestation, and the damage of acid rain. He also includes some of his personal adventures, such as his visit to the ATTO, a 325m tall tower in the middle of the Amazon Rainforest, and the exploits of others, such as a bush pilot’s flight along the ‘flying river’ above the Amazon.
A Trillion Trees champions the role of trees in more than just the fight against climate change, but also in the daily lives of everyday people. The tales of forest regeneration tell of the economic value of trees, through tourism, increased resources, and even ‘inspiration for artists’. Pearce presents the debate of rewilding versus replanting forests, asking who should be responsible for the regeneration of our forests and whether we should be taking an active role at all. The ‘great forest restoration’, as Pearce puts it, is occurring less due to the many government plans and promises of replanting, and more through the process of rewilding. Where farmers and landowners have stepped back, Pearce notes that nature seems to move in, allowing much of the fields and pastures to revert to shrubland and then to woodland. The return of wildlife soon follows.
In a world scrambling for solutions to combat climate change, the notion of stepping back and taking a passive role in regeneration may be a daunting one. However, it is not the only solution Pearce suggests. In the final section, Forest Commons, the author advocates for the rights of indigenous people to own and manage the land and forests within their traditional/ancestral territories. The rate of deforestation is far less in areas owned and managed by indigenous people than in other areas, even nature reserves, with communities seeming more resilient against threats such as illegal logging than government-owned parks.
This book closes by paying homage to the wild spaces near the author’s home in London, their ability to filter out noise and pollution, and the calming, cooling effects trees can have in otherwise overheated cities. After a book full of adventure and debate, the postscript acts almost like the ‘forest bathing’ it discusses, ending the book in a calmer tone that calls for more woods full of darkness and gnarled, twisted yew trees and forests that harken back to the lost primaeval wilderness.
The UK coast is home to many different bird species, which play a key role in the coastal ecosystems. They depend, directly and indirectly, on the marine and coastal environment. Seabirds are often used as bioindicators of marine ecosystems as they are easy to detect and survey, and are top predators; their presence and abundance can indicate the health and status of the habitat and food chain.
This guide contains some key identification features to look out for while out birdwatching by the coast. It is possible to see birds along our coastline throughout the year, but in late spring and early summer, particularly around June, many seabird species are feeding chicks. This is, therefore, the best time of year to spot some of our iconic coastal birds.
Very little equipment is needed for birdwatching, but it is generally recommended to bring a pair of binoculars or a scope, as this helps to see the less obvious features that aid in identifying species. These also allow you to observe without getting too close and disturbing the wildlife. A pen and notebook to keep a record of the species you spot is also a good idea, along with a field guide for the species not mentioned on this list.
Herring gull (Larus argentatus)
Size: length (L): 54-60 cm, wingspan (WS): 123-148cm
A widespread and common (though declining) gull species across the UK. They are large white birds with grey back and wings (tipped with black), a yellow bill and pink legs, and can be seen far inland in almost any habitat from the coast to farmland, moorland, town and city. This highly versatile species is our archetypal ‘seagull’.
Lesser black-backed gull (Larus fuscus)
Size: L: 48-56cm, WS: 117-134cm
Slightly smaller than the herring gull with darker slate-grey back and wings. Look out for yellow legs which are a key identifier of this species. Favours rocky coasts but is also found inland in mixed flocks with other gulls and around inland lakes.
Great black-backed gull (Larus Marinus)
Size: L: 61-74cm, WS: 144-166cm
These are very large and stocky gulls with a dark grey back and wings, a thick-set yellow bill and pink legs. This species are far more prominent along coastal areas and nest largely on rocky islands.
Black-headed gull (Chroicocephalus ridibundus)
Size: L: 35-39cm, WS: 86-99cm
Another widespread and common species often found inland, black-headed gulls have white heads for most of the year, often with a prominent black ear spot. In the summer, adult birds heads turns a dark chocolaty brown. They also have a red bill and red legs.
Kittiwake (Rissa tridactyla)
Size: L: 37-42cm, WS: 93-105 cm
A somewhat slight looking gull, white bodied with pale grey back and wings and black wing tips. They have a small yellow bill, dark eyes and black legs. Predominantly a summer breeding species in the UK and very rarely seen away from the coast, though they are known to form colonies within urban areas near ports.
Common tern (Sterna hirundo)
Size: L: 34-37cm, WS: 70-80 cm
Slight, slender and angular birds, often breeding in colonies around coastal lakes and lagoons, common terns are bright white with a light grey back and wings, a deeply forked tail, black cap and red legs and bill. Their bill has a black tip.
Arctic tern (Sterna paradisaea)
Size: L:33-39cm, WS: 66-77 cm
For much of the UK Arctic terns will be spotted on passage during their incredibly long migration. They are superficially similar to common tern though their bill is usually plain red with no black tip.
Fulmar (Fulmarus glacialis)
Size: L: 43-52cm, WS: 101-117 cm
Fulmar, though gull like in appearance, are petrels, related to albatrosses and shearwaters. They have a thick-set ‘tube-nose’ bill which they can spit foul-smelling oil from to deter predators from their nesting sites. They nest on sheer cliff faces and fly on stiff and shallow wing beats.
Gannet (Morus bassanus)
Size: L: 85-97cm, WS: 170-192 cm
Gannets are large white seabirds with a distinctive yellow head and long pointed wings with black tips. They also have a long pointed grey bill and white pointed tale. They can be seen flying high over the sea and circling before plunging at great speeds into the water in pursuit of food.
Guillemot (Uria aalge)
Size: L: 38-46cm, WS: 61-73 cm
Guillemots come to land only in the summer to breed and do so in large colonies on sheer cliff faces. Adult birds can often be seen ‘rafting’ at sea below the colony also. They have a brown/black head, back, wings and tail and white underneath. There is also a ‘bridled’ form where the birds have a white ring around their eye with a stripe behind it.
Razorbill (Alca torda)
Size: L: 38-43cm, WS: 60-69 cm
Razorbills are superficially similar to guillemot: black on their wings, back, head and tail and white underneath. An easy distinction between the species can be made however, by the razorbills deep thick-set blunt bill, where the guillemot has a longer slim bill. They are another summer breeder, wintering in the northern Atlantic, and favouring sheer rocky cliffs and islands for nesting.
Puffin (Fratercula arctica)
Size: L: 28-34cm, WS: 50-60 cm
Unmistakeable small seabirds with a black back and white underneath. They have a white face with dark eyes set in dark triangular markings and an iconic vibrantly colourful bill. They are a summer visitor predominantly in large nesting colonies on islands, where they nest in burrows along vast grassy banks.
Cormorant (Phalacrocorax carbo)
Size: L: 77-94cm, WS: 121-149 cm
A large long-necked black bird, with a white face and yellow and grey bill. Cormorants are often seen inland on rivers and lakes, and in harbours where they extensively dive for their food and then stand to dry with their wings characteristically spread wide.
Shag (Phalacrocorax aristotelis)
Size: L: 68-78cm, WS: 95-110 cm
Shags are similar in appearance to cormorants though smaller, with a slimmer bill. Adult birds are entirely black (lacking the white face of cormorants) though still they have a yellow and grey bill. Shags are more strictly coastal and seldom seen inland, they also have a distinctive black crest on the top of their head.
Rock pipit (Anthus petrosus)
Size: L: 15.5-17cm
Synonymous with the coast, these small, streaked brown/grey birds (with pale underside) are commonly seen flitting from rock to rock with a swift undulating flight. They have a light peeping call and can be seen perching around harbour walls -they are often quite plucky and approachable.
Lavishly illustrated with 239 full-colour plates, this is the first comprehensive guide since Harrison’s 1983 opus, covering all known seabirds, beginning with seaducks and grebes and ending with cormorants and pelicans.
Containing over 650 colour photographs showing every seabird species likely to be encountered in European waters, this is an essential field guide for seawatching. Key features of each species are depicted in typical field conditions, with particular attention paid to shape and flight action, as well as plumage.
This is the first book to outline and synthesize the myriad of threats faced by one of the most imperilled groups of birds on earth. With more than half of all 346 seabirds worldwide experiencing population declines, this book will be an important resource for researchers and conservationists, as well as ecologists and students.
This title offers the most up-to-date guide for gull identification in Europe and beyond. Using a direct and visual approach, this guide provides accounts of the 45 species of gulls found int he Western Palearctic, extensively represented in nearly 1,400 colour photographs.
From cormorants to kittiwakes, and guillemots to gulls, this 8-panel laminated fold-out chart features 28 of the birds you can see around the coastline of the UK in the summer. Birds are shown in their adult summer (breeding) plumage.
These lightweight and compact binoculars are easy to transport and store, with a weatherproof design that makes them ideal for use in the field whatever the weather.
These high-end binoculars offer outstanding optical performance in a compact and lightweight body. Their wide field of view is perfect for surveying large landscapes or fast-moving animals.
This self-adjusting harness reduces pressure on the neck for prolonged binocular use. The unique loop attachment system enables the harness to quickly snap in place and the binoculars to slide along the strap for use.
Durable, lightweight and with excellent image quality, this compact scope is ideal for beginners or experienced birders looking for a portable alternative.
This high-end spotting scope offers a luxury viewing experience, with dual focus engineering providing a smooth, easy operation. The unparalleled image quality assures that key identification features will be easy to pick out.
Marine mammals, including seals and dolphins, are generally well-loved and charismatic species. Some people may be surprised by the variety of marine mammals we are lucky enough to have living around and visiting our coasts.
In this guide we will summarise a number of the marine mammal species you are most likely to spot in UK waters, and how to identify them. Identifying marine mammals can be a rather challenging task as often only a bobbing head or fin is visible, but knowing what features to look out for can sometimes be enough to make a fairly confident identification.
It is very important to note that seals and cetaceans are legally protected in the UK and all efforts should be made not to cause disturbance. It is strongly recommended that you do not approach marine mammals in person or by boat – any interactions should be fully on their terms.
Seals (Pinnipeds)
Two species of seal make our coasts their home: the common and grey seals. Both species are members of the family Phocidae, the true seals. Unlike other pinnipeds, such as sea lions, the true seals lack external ear flaps hence their other name, the earless seals.
Common Seal – Phoca vitulina
Also known as harbour seals due to their common presence in these locations.
Appearance: Rather cat-like in appearance, with a relatively shorter snout than the grey seal and a more concave forehead. Their nostrils are closer together than the grey, creating a ‘V-shape’. Often the pelage (coat) is grey and speckled. Both males and females of this species look similar.
Behaviour: When on land, the common seal can be seen to lay on its side and hold its tail and head in the air forming a banana-like shape. They tend to be found in smaller aggregations on land than grey seals, leaving more space between individuals.
Where are they seen? Despite their name, common seals are seen less frequently than grey seals, with their population numbers less than half that of the grey. Abundant in northern England and Scotland, but rarely seen in the south. Generally seen coastally, or hauled out on rocks and beaches.
Grey Seal – Halichoerus grypus
The grey seal is the most common seal species in the UK, and the UK population makes up roughly 40% of the global population.
Appearance: Grey seals have a ‘blotchy’ pelage and tend to be darker than common seals. They are also larger in size, have a more prominent snout and their nostrils are separate and roughly parallel. Female grey seals can be more difficult to separate from the common seal as they do not have such a striking snout.
Behaviour: Rather gregarious seals, they often haul out in large colonies during the breeding and moulting season. Grey seals are generally curious and on occasion will approach a boat or humans in the water to investigate (see note about disturbance, any interactions should be on the animal’s terms).
Where are they seen? Common around the UK, particularly along the western coast, Scotland and Norfolk. Generally seen coastally, or hauled out on rocks and beaches.
Dolphins and Whales (Cetaceans)
At least 25 species of cetacean have been spotted in UK waters, although significantly fewer are regularly seen. Some species are resident year-round while others simply pass through seasonally. All cetaceans, including porpoises and dolphins, are technically whales, although commonly only the larger species are referred to by this name. They are split into two groups: the toothed whales that actively hunt prey and the larger baleen whales, that use sheets of keratin (baleen) to filter feed.
Toothed whales (Odontocetes)
Harbour porpoise – Phocoena phocoena
Also known as the common porpoise. The name porpoise is derived from ‘porcus’, the Latin word for ‘pig’. Colloquially they are sometimes referred to as the ‘puffing pig’ due to the characteristic ‘chuff’ made when surfacing.
Appearance: The smallest cetacean in the UK, not exceeding a length of 1.5 metres. Their dorsal fin is small and triangular and their head is rounded at the front, lacking a clear beak.
Behaviour: Generally seen as individuals or in small groups with 2-5 members. They often surface three or four times before disappearing for a longer dive. Elusive and unlikely to approach boats.
Where are they seen? Seen nationwide in shallow, coastal waters.
Common dolphin – Delphinus delphis
Appearance: A sleek and agile dolphin with an elongated beak and sickle-shaped dorsal fin. Easily identified by their cream and white ‘hourglass’ colouration.
Behaviour: Acrobatic and generally inquisitive dolphins. Common dolphins are frequently seen bow-riding alongside boats and leaping from the water. On occasion, groups join together to form a super-pod of hundreds of individuals. If a group of cetaceans this large is spotted in UK waters, it is almost certainly common dolphins!
Where are they seen? They tend to spend most of their time offshore in deeper waters, so are more likely to be seen by boat rather than from the shore.
Bottlenose dolphin – Tursiops truncatus
Appearance: A large, muscular dolphin with fairly uniform grey colouration. British bottlenose dolphins are the largest in the world, presumably to allow them to cope with our colder waters.
Behaviour: Travel and feed in small-medium pods, although lone animals have been seen around the UK.
Where are they seen? Bottlenose dolphins can be spotted all around our coasts if you are lucky, but are most likely to be seen in the Moray Firth, Cardigan Bay and Cornwall, where resident pods reside.
Risso’s dolphin – Grampus griseus
Appearance: Unmistakable dolphins with distinct colouration except as calves. Risso’s begin their lives dark grey but become paler and scarred with age. These marks occur from social interactions with other Risso’s and during predation events, such as with squid.
Behaviour: Studies show Risso’s dolphins to be social animals that remain in long-established pods. They are fairly active at the surface of the water and can be seen ‘spy-hopping’ – holding themselves vertically in the water with only their heads bobbing above the surface.
Where are they seen? In deeper, offshore waters. Generally spotted along the west coast of Scotland and around the Isle of Man.
Orca – Orcinus orca
Appearance: Striking and characteristic large black cetaceans with white eye and saddle (behind dorsal fin) patches. Male orcas have the largest dorsal fin of any species at up to 6ft, significantly taller than the female orcas.
Behaviour: Orcas are very social animals that remain with their maternal pod. Different groups display different feeding strategies, tending to focus on either smaller marine mammals or fish. Orcas are fairly active at the surface and can be seen spy-hopping or tail-slapping the water.
Where are they seen? The UK’s only resident pod (8 individuals) tends to be seen on the West coast of Scotland but were spotted roaming as far south as Cornwall in early 2021. Further transient groups appear in the summer but are generally limited to northern Scotland, Orkney and Shetland.
Baleen whales (Mysticetes)
Minke Whale – Balaenoptera acutorostrata
Appearance: The smallest baleen whale seen in the UK at around 9 metres in length when fully grown. A dark grey whale with a white underside with a sickle-shaped dorsal fin located roughly two-thirds along the back. If you’re lucky enough to spot the pectoral (side) fins, the white ‘armbands’ will confidently identify this species.
Behaviour: Generally seen alone or in small groups. Minke can be seen to lunge feed at the surface, side-lunging with open mouths to take in large quantities of water and therefore prey. From afar, aggregations of seabirds can be the first hint of such a feeding event.
Where are they seen? Minke are the most commonly spotted baleen whale and can be seen nationwide. Sightings are significantly higher around Scotland and the south-west.
Fin Whale – Balaenoptera physalus
Appearance: The second largest whale in the world, reaching up to 24 metres in the northern hemisphere. Very dark colouration on the upper body, with the dorsal fin placed far back on the back. The fin whale has an asymmetrically coloured lower jaw, with bright white only present on the right-hand side (as shown in the above image).
Behaviour: Seen on their own, or in small groups of up to 7 individuals. When diving their tail does not rise above the surface, unlike some other large whales.
Where are they seen? Rare in UK waters, but most likely to be seen around northern Scotland and the Hebrides, although sightings have occurred off Cornwall and Ireland in recent years.
In the lead up to the 26th UN Climate Change Conference of the Parties (COP26) in November of this year, we are writing a series of articles looking at some of the toughest global climate crisis challenges that we are currently facing. This post looks at the evidence for and challenges posed by a global decline in insects.
What is the evidence for a global insect armageddon?
One of the first meta-analyses of insect population decline was published in 2014 by Dirzo et al. in Science under the title ‘Defaunation in the Anthropocene’. This seminal paper reported that 67% of monitored invertebrate populations showed 45% mean abundance decline and warned that ‘such animal declines will cascade onto ecosystem functioning and human well-being’. Three years later, Hallmann et al. (2017) published the results from 27 years of malaise trap monitoring in 63 natural protection areas in Germany, and concluded that insect biomass had declined by more than 75% during this time. This paper in particular was widely reported in the media, creating widespread concern among the public of an impending insect armageddon, or ‘insectageddon’.
Since then, several other reports have continued to draw attention to declines in insect abundance, biomass and diversity around the world (for excellent reviews see Wagner (2020) and Sánchez-Bayo & Wyckhuys (2019)). However, many of these studies have been restricted to well-populated areas of the US and Europe and there is little information available to assess how these patterns compare with other less well studied regions.
Despite the abundance of data suggesting a pattern of global insect decline, many studies show conflicting results, with datasets from a similar area often reporting different patterns. There is also evidence that some insects are faring well, particularly in temperate areas which are now experiencing milder winters. Species that benefit from an association with humans, such as the European honeybee, may also be experiencing an advantage, along with certain freshwater insects that have benefited from efforts to reduce pollution in inland water bodies.
What are the challenges in assessing and predicting insect population trends?
In comparison to vertebrate groups, comprehensive long-term datasets are rare for invertebrates. This is primarily down to the fact that invertebrates are incredibly species rich and so, even for those that have been formally identified and described, a considerable amount of skill and knowledge is required for reliable identification. In addition to this high level of expertise is the need for large amounts of field equipment, which means that long-term, comprehensive studies can be expensive and difficult to fund.
Both historical and current invertebrate monitoring data tends to come from a small number of wealthy and well-populated countries (usually the US and western Europe), and there are comparatively few datasets available from tropical and less developed areas. Unfortunately, these understudied countries and regions tend to be the areas where we might expect to find the most diverse and species rich populations of invertebrates.
Other challenges relate to the way that data is collected. Using total insect biomass as a measure provides a useful large-scale perspective and provides information relevant to ecosystem function. It also minimises the problems involved with taxonomy and identification. However, using this measure means that species-level trends are completely overlooked.
What are the main stressors affecting insect populations globally?
Studies suggest that the main stressors impacting invertebrates are changes in land-use (particularly deforestation), climate change, agriculture, introduced and invasive species, and increased nitrification and pollution. However, it is rare that a single factor is found to be responsible for monitored declines and the situation has been described as being akin to ‘death by a thousand cuts’.
In a recent special edition of PNAS, that looked in depth at the available research and literature on insect decline in the Anthropocene, climate change, habitat loss/degradation and agriculture emerged as the three most important stressors.
Where do we go from here?
Traditionally, conservation has focused on rare and endangered species. However, with mass extinctions and large scale invertebrate loss, which include declines in formerly abundant species, a different approach is required. Invertebrates form an important link between primary producers and the rest of the food chain, and play a key role in most ecosystems. They provide numerous ecosystem services such as pollination, weed and pest control, decomposition, soil formation and water purification, and so their fate is of both environmental and economic importance.
There are several things to be positive about within the realms of invertebrate conservation: over the past decade, funding to support insect conservation has been growing and, in many countries, there are now substantial grants allocated to monitoring and mitigation projects. The EU and US have seen widescale banning of certain pesticides following research demonstrating their impacts on both economically important pollinators and other fauna. Finally, citizen science projects to study invertebrate populations are becoming both numerous and successful, greatly increasing the amount of comprehensive, long-term data that is available to inform conservation decisions.
Despite this, much more long-term data on invertebrate populations is required, particularly from regions outside of Europe and the US, such as tropical areas of the Americas, Africa and Asia. Attention to factors such as the standardisation of survey techniques and improved data storage and accessibility are also important, as well as the utilisation of new methods including automated sampling/counting equipment and molecular techniques. Using the information available, evidence-based plans for mitigating and reversing declines are desperately required.
All of this takes time however, and we need to act now. Even without comprehensive species-level data, we know that a biodiversity crisis is occurring at a rate serious enough for it to have been termed the ‘6th Mass Extinction’. Individual, group, nationwide and global action will all be required to combat this. Widescale change in societal attitudes to insects will undoubtedly need to play a role in this process, alongside global efforts to slow climate change and develop insect-friendly methods of agriculture.
Summary
• Numerous studies have reported large-scale declines in insect populations, with several estimating a loss of approximately 1–2% of species each year.
• The availability of high-quality and long-term datasets is a limiting factor in assessing population trends. Furthermore, available data tends to be from well-populated and historically wealthy areas such as the US and western Europe, with the diverse and species-rich tropics severely under-researched.
• The main stressors thought to be impacting insect populations globally are climate change, habitat loss/degradation and agriculture. In most, if not all of these cases, a combination of these and other factors are likely to play a role.
• Although there are some aspects of insect conservation to be positive about, much work still needs to be done. Further monitoring and recording are required, particularly in poorly studies areas, in order to inform conservation decisions. Simultaneously, local and global efforts must be made to slow climate change, halt the destruction of ecologically important habitats and develop nature-compatible methods of agriculture.
Eye-opening, inspiring and riveting, Silent Earth is part love letter to the insect world, part elegy, part rousing manifesto for a greener planet. It is a call to arms for profound change at every level – in government policy, agriculture, industry and in our own homes and gardens, to prevent insect decline. Read our extended review.
In a compelling global investigation, Milman speaks to those studying this catastrophe and asks why these extraordinary creatures are disappearing. Part warning, part celebration of the incredible variety of insects, The Insect Crisis highlights why we need to wake up to this impending environmental disaster.
In this latest volume in the British Wildlife Collection, Trevor Beebee examines the story so far for our species and their ecosystems, and considers how they may respond in the future. Check out our interview with Beebee, where we discuss the background of this book, his thoughts on conservation and his hopes for the future.
Environmental campaigner Vicki Hird demonstrates how insects and other invertebrates, such as worms and spiders, are the cornerstone of our ecosystems and argues passionately that we must turn the tide on this dramatic bug decline.
Weaving a vivid and personal narrative, Haddad illustrates the race against time to reverse the decline of six butterfly species. A moving account of extinction, recovery, and hope, The Last Butterflies demonstrates the great value of these beautiful insects to science, conservation, and people.
Hans-Dietrich Reckhaus discusses the beneficial and harmful effects of insects and explains their development and significance for biodiversity. This second, fully reviewed and enlarged edition provides new insights into the value of species seen as pests, insect development and their decline in different regions in the world.
Here we review the Anabat Scout from Titley Scientific. The Scout is an easy to use active bat detector that offers excellent quality live audio and recording, plus many handy surveying features and durability that sets it apart from other detectors. It uses heterodyne, auto-heterodyne and frequency division audio that can be recorded in either full spectrum or zero crossing files.
Designed with professional surveyors as well as the more serious bat enthusiast in mind, the Scout is an ideal detector to take on bat emergence and transect surveys. This is thanks to great features such as a bat counter and GPS tracking transect mode.
How we tested
In early July 2021, we tested the Scout outside an old barn in South Devon to monitor the dusk emergence of several bat species. The building was known to host many common pipistrelles, brown long-eared, lesser horseshoes and some myotis species. We wanted to see how easy the detector was to use in the setting of a busy emergence and get a feel for its recording quality and its special features. The audio was set to auto-heterodyne to see how good this feature would be with multiple bats close by. Under the trigger settings is the option to adjust the sensitivity, which we set to high as there was unlikely to be too much undesired noise in this setting.
What we found
Firstly, it is worth noting just how lightweight (at 160 grams without batteries) and easy to hold the Scout is with its handy wrist lanyard and comfortable fit within your hand. These features are particularly important when undertaking long surveys and holding other equipment such as a clipboard for instance.
The OLED display screen is small, but bright, so key information such as peak frequency and time is easy to note in the dark. With just key information visible, the screen does not become too “busy” unlike some detectors, which in some circumstances is a real advantage as it avoids too much distraction. The buttons all glow in the dark, which we found very useful once it had become completely dark, as it kept navigation simple, without having to use a torch.
One of the Scout’s most handy features are the in/out bat counter buttons which enable you to easily tally the number of bats recorded coming out and back into a roost, without the need to look away to make notes and perhaps miss bats. The counter also time and date stamps and geotags each count (CSV file output), so saves you having to manually note this data.
The Scout has a transect mode which notes a GPS coordinate every second so maps out your route as you walk it. It also logs another GPS coordinate for every bat recording made which produces detailed transect maps.
We found that the adjustable volume control was very good and loud enough when needing to compensate for background noises such as a passing lorry.
Also noteworthy was the Scout’s ability to record voice notes. Once it has become fully dark or if you are surveying and need to keep your eyes fixed on bat watching, then the ease of just speaking into the device to add survey notes or further information is very helpful.
The Scout was very productive at picking up all the bats we encountered during the evening (although sometimes a brown long-eared emerged without calling and was missed). The auto-heterodyne tuning to the peak frequency was superb and saved much time. On a few occasions, we switched to manual heterodyne which enables you to adjust the frequency by moving the up and down arrows. This setting would be useful when first teaching beginners. The Scout’s range is also excellent, which was demonstrated when a high flying noctule was picked up probably over 30 – 40 meters away.
The recordings were always clear through the built-in speaker, although there is also the option to attach a 3.5mm headphone jack. All recordings come with GPX track files attached. This gives accurate GPS data, that when viewed on the free software: Anabat Insight, a .KML (Keyhole Markup Language) file can be generated using Google Earth which will show your route with location tags for each bat recording.
All recordings were stored on an SD Card (recommended min: 32GB and max 512GB) and then output via WAV (Full spectrum) and Anabat sequence files (Zero Crossing).
Battery life lasted roughly 10 hours on 2 x AA (NiMh, Alkaline or Lithium) batteries with the remaining memory space and battery life displayed on screen, so we could keep a check during the evening.
Our Opinion
The Anabat Scout is certainly one of the easier to use, professional bat detectors available. It is highly accurate with its triggers and by being so lightweight and practical it makes for an ideal choice for both ecological surveyors and keen naturalists alike. The Scout has been designed with the needs of surveyors in mind and even those new to bat detecting, will find it simple to use and highly rewarding.
The main limitation found was that the Scout does not display full spectrograms like the Anabat Walkabout, therefore beginners particularly, may not find this detector so helpful for learning the differences in calls and identification in the field.
Overall, we feel the Scout offers very good value as an active detector that will fulfill the needs of most ecological surveyors. Its advantage of being incredibly easy to use and get to know, makes it fantastic for beginners, subcontractors and educational purposes also.
The Anabat Scout can be found here. Our full range of active bat detectors can be found here.
If you have any questions about our range or would like some advice on the right product for you then please contact us via email at customer.services@nhbs.com or phone on 01803 865913.
Many books in the Collins New Naturalist Library are underpinned by ecology, but the latest addition to the series is the first to be devoted to the science in its own right. In Ecology and Natural History, David Wilkinson provides an insightful and highly accessible account of the core ecological concepts and brings them to life with examples of classic research sites and studies from across Britain.
David Wilkinson is Visiting Professor in Ecology in the School of Life Sciences at the University of Lincoln and Honorary Research Fellow in Archaeology at the University of Nottingham. He has wide interests in ecology, and in recent years has written articles for British Wildlife on such varied subjects as scent-based mimicry in wild plants and animals, lichens as composite organisms, and autumnal colour change in leaves. Here, David has kindly answered some of our questions about his new book.
Ecology is a complex discipline, encompassing all the amazingly diverse ways in which living organisms interact with one another and with their environment. What drew you to ecology as a topic for your book, and how did you set about tackling such a wide-ranging subject?
As you say ‘Ecology is a complex discipline, encompassing all the amazingly diverse way living organisms interact with one another and their environment’ – with a topic as grand as this why would you write a book on anything else! Both of my previous books (for Oxford University Press) had been on aspects of ecology, but written for a more technical audience. Having walked away from my academic day job I now felt I had the time to try and write something more accessible, but still scientifically accurate. Most of the most pressing global problems are related to ecology, so there is an obvious need for as many people as possible to have some idea of basic ecological concepts. The approach grew out of over a quarter of a century’s experience of introducing the basic ideas of ecology to undergraduates.
Chapters are split by topic but also by location, each one beginning with a scene from the site of a classic ecological study. What inspired this approach?
It seemed the obvious approach, as although this is a book on ideas I wanted to embed them in what you see in the field. The first chapter I wrote was chapter 2 which made a lot of use of Cwm Idwal in Snowdonia. Jonathan Silvertown (plant ecologist and science writer) was the member of the New Naturalist editorial board who oversaw my book. He liked the site based approach and encouraged me to use it throughout the book (his own popular book on plant diversity ‘Demons in Eden’ had used a similar approach). In many ways the approach grew out of my tendency to ‘tell stories’ when talking about ecology to beginning undergraduates. So in part the book is my lecturing style turned to prose.
Were you familiar with your chosen locations before embarking on writing, or did you make trips as part of your research for the book?
Most of the locations I used to open chapters were sites I was familiar with, but the two exceptions were Downe Bank and the Isle of Cumbrae – writing the book provided a great excuse to visit both of these. Most of the sites were visited on one or more occasion during the three years I worked on the book – the exceptions were Selborne (which I had visited a couple of years before I started writing) and Rothamsted, where the description is based on a visit in 2005. A highlight of the writing was a week’s fieldwork in the Cairngorms, taking photos for the book.
Smaller life forms such as bacteria and protists feature prominently in various chapters. How important are these organisms in helping us to understand the structure and function of ecosystems?
A key theme of the book is the importance of such organisms. Considered from a genetic or biochemical perspective most of the diversity of life on Earth is microbial. Considered from a geological perspective for most of the history of life on Earth all ecology was microbial ecology, as microbes were the only life forms around. In ecological systems today they are still crucial. Many people vaguely realise that they have some importance in decomposition and nutrient cycling, but also much of photosynthesis (and related oxygen production) is by microbes rather than larger plants. Historically microbes have been hard to study in the wild, being by definition too small to see without microscopy. However, molecular methods (using DNA or RNA) are making things much more tractable, and now microbial ecology looks poised to be one of the big growth areas in ecological research.
You were able to draw on a number of examples of high-profile and long-running experiments from British sites. How influential have studies in Britain been for ecology as a science?
Ecology has a long history but really starts to take off as a science in the early 20th century. It started to develop earlier in Britain than in most countries, indeed the British Ecological Society (founded in 1913) was the first such society anywhere in the world. Because of this several of the key early studies that helped develop the basic ideas of ecology took place in Britain.
A number of the experiments described were initiated in the early/mid-20th century. Has there been a decrease in the creation of new long-term studies in recent decades and, if so, what are the implications for conservation and ecology?
Because of the relatively early start of academic ecology in Britain the country has a number of very long running ecology field experiments. For example two I write about in the book are The Park Grass experiment at Rothamsted (started 1856) and the Godwin Plots at Wicken Fen (started 1927). Neither was started with the idea that they would run for 100 years or more – there is a large element of chance in their long-term survival. However, once an experiment has been running for a long time then people start to realise that such long runs of data are important and try and find the resources to continue them. More recent examples include (amongst many) the Buxton Climate Change Impacts Lab (which commenced in 1993 on limestone grassland in the Peak District) and grazing experiments set up in the Ainsdale Dunes system in Merseyside (started in 1974). But to be really long term requires luck and/or a succession of people determined enough to keep them going against the odds.
Finally, could you tell us about your plans for the future? Do you have any more writing projects lined up?
I have quite a list of books that would be interesting to write. The one I am most keen to do next is envisaged as a series of linked essays on ecology, evolution and the environment, as I would like to do an accessible general book that uses examples from around the world (rather than having the British focus of a New Naturalist). While I have an outline of the idea it’s in very early stages and I haven’t yet found a publisher for it. More long term another book that requires the extensive fieldwork that went in to the New Naturalist would provide a good excuse to not get trapped at a computer. I also have several ongoing ecological research projects.
Ecology and Natural History
By: David M. Wilkinson
Hardback | Published June 2021 | £52.99 £64.99 Paperback | Published June 2021 | £27.99 £34.99
All prices correct at the time of this article’s publication.
Forest Insects in Europe has been written not only with professional entomologists in mind, but also for nature lovers generally. The descriptions of the various roles insects play in forest ecosystems are intended to be easily comprehensible, but still scientific.
We recently caught up with the book’s author, Beat Wermelinger, who works as a Senior Scientist at the Swiss Federal Research Institute WSL. His research interests include bark beetles and natural enemies, Biodiversity, windthrow succession, climate change and neozoa. Beat answered our questions in German and our bi-lingual team members were excited to translate these to English for us. Discover more below in both languages.
1) Could you tell us a little bit about your background and how you came to write Forest Insects in Europe: Diversity, Functions and Importance?
I have been working at the Swiss Federal Research Institute WSL (Swiss Federal Institute WSL) (a forest research institute) for 30 years and until recently was the head of the entomology group. Simultaneously, I have also been teaching forest insects at the ETH Zurich. During this time, a large pool of knowledge and information has accumulated. I have also been a passionate insect photographer for just as long, which is reflected in an image database of around 16.000 insect photos. These two strands provided an ideal basis for conveying the importance and fascination of insects in one scientifically based book, which was also richly illustrated with photos, for both specialists and all those interested in nature.
Können Sie uns etwas über Ihren Hintergrund erzählen und wie Sie dazu kamen, Forest Insects in Europe: Diversity, Functions and Importance zu schreiben?
Seit 30 Jahren arbeite ich an der Eidgenössischen Forschungsanstalt WSL (Swiss Federal Institute WSL) (einem Waldforschungsinstitut) und leitete dort bis vor kurzem die Gruppe Entomologie. Zugleich unterrichte ich fast gleich lang zu Waldinsekten an der Hochschule ETH in Zürich. In dieser Zeit hat sich ein grosser Fundus an Kenntnissen und Informationen angesammelt. Ausserdem bin ich seit mindestens ebenso langer Zeit ein passionierter Insektenfotograf, was sich in einer Bilddatenbank von rund 16.000 Insektenbildern niedergeschlagen hat. Diese beiden Grundlagen boten eine ideale Basis, die Bedeutung und Faszination von Insekten in einem zwar wissenschaftlich fundierten, aber auch reich mit Fotos illustrierten Buch sowohl Fachpersonen als auch allen Naturinteressierten zu vermitteln.
2) The book tackles a vast array of insect groups and ecological functions – were there any particular challenges in collating so much information in one place?
Much of the information comes from my readings or lectures. However, since I wanted to portray the ecological and economic importance of forest insects as broadly as possible, I still had to review a lot of published material. Above all, I wanted to support quantitative data with accurate citations. Owing to the Internet, such research is easier today than it was 20 years ago… Fortunately, I also had my own photographs on almost all topics.
Das Buch befasst sich mit einer Vielzahl von Insektengruppen und Funktionen – gab es besondere Herausforderungen, so viele Informationen in einem Buch zusammenzufassen?
Ein wesentlicher Teil der Informationen stammt aus meinen Vorlesungen oder Vorträgen. Da ich aber die ökologische und ökonomische Bedeutung von Waldinsekten möglichst breit darstellen wollte, musste ich doch noch Einiges an Literaturarbeit leisten. Vor allem wollte ich quantitative Angaben mit korrekten Literaturzitaten abstützen. Dank dem Internet sind solche Recherchen heute einfacher als noch vor 20 Jahren… Erfreulicherweise hatte ich auch zu fast allen Themen eigene Bilder.
3) Are there any insect groups that hold a particular interest for you?
Professionally, I am mainly concerned with wood-dwelling insects. I am especially interested in the bark beetles, and their natural enemies as well as the intensive interactions with their host trees. Bark beetles are known to be pests, but they are also pioneers in the decay of wood. I also deal with the wood-dwelling longhorn beetles and jewel beetles, which often lend themselves to photography because of their size and beauty. For decades I have dealt with the development of their biodiversity after disruptive events such as storms or fire. The social red wood ants or the galling insects also fascinate me with their ingenious way of life.
Haben Sie eine Insektengruppe, an der Sie besonders interessiert sind?
Beruflich beschäftige ich mich vor allem mit holzbewohnenden Insekten. Mich interessieren die Borkenkäfer, ihre natürlichen Feinde und die intensiven Wechselwirkungen mit ihren Wirtsbäumen. Borkenkäfer sind zwar als Schädlinge bekannt, sie sind aber auch Pioniere beim Holzabbau. Weiter befasse ich mich mit den holzbewohnenden Bock- und Prachtkäfern (longhorn beetles, jewel beetles), die sich oft ihrer Grösse und Schönheit wegen auch zum Fotografieren anbieten. Über Jahrzehnte habe ich mich mit der Entwicklung ihrer Artenvielfalt nach Störungsereignissen wie Sturm oder Feuer beschäftigt. Auch die staatenbildenden Waldameisen (red wood ants) oder die gallbildenden Insekten (galling insects) faszinieren mich durch ihre ausgeklügelte Lebensweise.
4) In Chapter 18, you discuss the severe and widespread decline of several insect groups. What has caused so many species to dwindle in European forests? And what is being done to address these threats?
There are two main causes for the decline in much of the forest insect fauna. The intensive use of wood in the past centuries has led to the fact that the forest area in Europe has decreased significantly over a long period of time, the trees no longer reach their natural age phase, and there were almost no dead trees that could slowly rot. In the case of many wood-dwelling insects that are dependent on so-called habitat trees or develop in decayed, thick tree trunks, this has led to a severe threat to their biodiversity. In recent decades, the forest area has increased again and in many countries the preservation of old trees and dead wood is being promoted. However, the impact is still modest.
A second reason is the fact that many shrubs and pioneer tree species such as willow and poplar have disappeared and the forests have often become more monotonous and closed. This mainly affects the forest butterflies. Today, clearings are created on purpose from which not only these insects, but also other light-loving forest species such as certain orchids or birds can benefit.
In Kapitel 18, erwähnen Sie den verbreiteten Rückgang mehrerer Insektengruppen. Was hat den Rückgang so vieler Arten in den europäischen Wäldern verursacht? Und was wird getan, um diese Bedrohungen zu begegnen?
Es gibt hauptsächlich zwei Gründe für den Rückgang eines grossen Teils der Waldinsektenfauna. Die intensive Holznutzung der vergangenen Jahrhunderte hat dazu geführt, dass die Waldfläche in Europa über lange Zeit sehr stark abgenommen hat, die Bäume nicht mehr ihre natürliche Altersphase erreichten, und fast keine abgestorbenen Bäume vorhanden waren, die langsam verrotten konnten. Dies hat bei vielen holzbewohnenden Insekten, die auf sogenannte Habitatbäume angewiesen sind oder sich in toten, dicken Baumstämmen entwickeln, zu einer starken Bedrohung ihrer Artenvielfalt geführt. In den letzten Jahrzehnten hat die Waldfläche zwar wieder zugenommen und in vielen Ländern wird der Erhalt von alten Bäumen und Totholz gefördert. Die Auswirkungen sind jedoch noch bescheiden.
Ein zweiter Grund ist die Tatsache, dass durch die Bewirtschaftung viele Sträucher und Pionierbaumarten wie Weiden oder Pappeln verschwanden und die Wälder oft monotoner und dunkler geworden sind. Dies wirkt sich vor allem auf die Wald-Tagfalter (forest butterflies) aus. Heute werden gezielte Auflichtungen durchgeführt, von denen nicht nur diese Insekten, sondern auch andere lichtliebende Waldarten wie bestimmte Orchideen oder Vögel profitieren.
5) A particular highlight of the book is the wonderful collection of insect photographs, most taken by you. Do you have any advice for people interested in insect photography?
The main problem when photographing small objects is always to be able to focus as much as possible on them. This requires a small aperture and therefore a lot of light. I photograph everything “hand-held” and therefore the shutter speed should be short. For these reasons, I almost always use a ring flash with separately controllable halves and 100 mm macro lens with my SLR camera. Nonetheless, even cameras with a small sensor (even mobile phones!) can nowadays produce surprisingly good images of larger, less volatile insects.
In order to photograph an insect as sharply as possible, you should position yourself so that the insect is parallel to the camera. At least the eyes should always be sharp. Of course, you can also choose a different level of focus for special effects.
In addition to technology, you need an eye for the little things in nature, patience and always a bit of luck! Knowledge of the behavior of certain groups of insects can also come to great advantage.
Ein besonderes Highlight des Buches ist die wunderbare Sammlung von Insektenfotos, die meisten davon von Ihnen aufgenommen. Haben Sie Tipps für Leute, die sich für Insektenfotografie interessieren?
Das Hauptproblem beim Fotografieren von kleinen Objekten ist immer, einen möglichst grossen Teil davon scharf abbilden zu können. Dies erfordert eine kleine Blende und damit auch viel Licht. Ich fotografiere alles “aus der Hand” und deshalb sollte die Verschlusszeit kurz sein. Aus diesen Gründen verwende ich mit meiner Spiegelreflexkamera und dem 100 mm Makroobjektiv fast immer einen Ringblitz mit separat steuerbaren Blitzhälften. Aber auch Kameras mit kleinem Sensor (sogar Handys!) bringen bei grösseren, wenig flüchtigen Insekten heutzutage erstaunlich gute Bilder. Um ein Insekt möglichst scharf abzulichten, sollte man sich so positionieren, dass das Insekt möglichst parallel zur Kamera steht. Mindestens die Augen sollten immer scharf sein. Natürlich kann man die Schärfenebene für spezielle Effekte auch anders wählen.
Zusätzlich zur Technik braucht es aber vor allem das Auge für die kleinen Dinge der Natur, Geduld und immer auch etwas Glück! Auch Kenntnisse des Verhaltens bestimmter Insektengruppen sind von grossem Vorteil.
6) What’s next for you? Do you have any projects that you are currently involved in that you would like to tell us about?
Professionally I am still working for another year, but of course my interest in insects will not vanish when I retire. I would like to use my pictures in other ways and maybe do another book. Above all, not surprisingly I would like to use the time to photograph insects in the great outdoors.
Was kommt als Nächstes für Sie? Haben Sie Projekte, an denen Sie aktuell beteiligt sind und die Sie mit uns teilen können?
Beruflich bin ich noch ein Jahr tätig, aber damit erlischt mein Interesse an Insekten natürlich nicht. Ich würde gerne meine Bilder noch anderweitig in Wert setzen und vielleicht noch ein weiteres Buch in dieser Art machen. Vor allem aber möchte ich die Zeit nutzen, um – wen wundert’s – in der freien Natur Insekten zu fotografieren.
In the new Summer 2021 issue of Conservation Land Management magazine (CLM) Dan Brown, ecologist and founder of Wild Discovery, provides an overview of thermal imaging technology and how it can be applied in wildlife surveys. Here you can read a summary of the article.
Thermal imaging was originally developed for military purposes but has since been deployed in a variety of fields, including increasingly so in conservation and ecology. It works by using medium- and long-wave infrared radiation to create a heat image called a thermogram – the varying temperatures can be displayed either as different colours, shades or as a monochromatic image. In light of its growing popularity in ecology, this article discusses how this technology can be used in wildlife surveys and what needs to be considered when doing so.
Field applications
One important benefit of using thermal imaging is that species that are usually difficult to survey, particularly cryptic or nocturnal species, can be readily detected. Ptarmigan, for example, can be tricky to spot in scree and boulder fields, and so the use of thermal imaging can be an efficient way to monitor an elusive species such as this with greater accuracy. Also, as this is a non-invasive surveying technique, the behaviour of wildlife can be observed with little disturbance.
Thermal-imaging technology has already been trialled in surveys of a number of different species. In the Forest of Dean, for example, the Forestry Commission uses thermal imaging to monitor wild boar, and the Mid Wales Squirrel Partnership uses it to monitor active red squirrel dreys. This technology can also complement acoustic monitoring for bat surveys – the species of bat can be determined using a bat detector, while thermal imaging can help to identify potential roost sites and enables the surveyor to count the number of individuals present.
Another advantage of thermal-imaging technology is that it works both during the day and at night. Studies of woodcock and nightjar have put this to good use – researchers have been able to locate day-roosting birds and also monitor their nocturnal activity, such as foraging behaviours and flight patterns, with minimal disturbance to the birds.
Potential for other uses in the field
But what else can thermal imaging be used for in species monitoring? Elsewhere in the world, thermal-imaging systems have been fitted to farm machinery to help detect ground-nesting bird species, a method that could be applied in the UK to monitor curlew, lapwing and stone-curlew. Similarly, attaching thermal-imaging equipment to drones could provide an opportunity to survey inaccessible species and areas.
And it doesn’t have to be just warm-blooded animals either. There is huge variation in heat signatures across the landscape, even between different tree species, and so using thermal imaging could aid searches for potential locations for roosting owls, for example, or help to identify possible basking spots for invertebrates and reptiles. There is also potential for this technology to be used to search for insects that display a distinct heat signature in low ambient temperatures, such as queen wasps and bumblebees or larger moths.
Considerations and limitations
When planning and designing surveys and fieldwork, there are a number of factors that need to be considered when using thermal imaging. For instance, its effectiveness can differ depending on the season or weather – the heat signatures of birds and mammals can be masked on sunny days, whereas these signatures are more detectable during overcast days when the ambient temperature is lower. In order to use this equipment effectively, adequate practice and training is required and although there are some training courses available, there is not a huge amount of published guidance on using thermal imaging for wildlife surveys. And even before choosing a thermal imaging scope, it is important to consider its intended use, its detection distance (as this varies between different models), and cost.
In the full article Dan Brown describes how thermal technology works, provides more detail on how thermal imaging can be applied to wildlife surveys and the benefits of doing so, and describes the resources and training that are currently available for ecologists using thermal imaging. Other articles that featured in the Summer 2021 issue include:
River restoration in the Avon catchment of the Cairngorms National Park
The Pirbright Red Deer Project – Surrey’s last ‘wilderness’?
Bats in churches: a complex conservation challenge
Insecticide-free agriculture – a sustainable approach for nature and farming
In this and every issue you can expect to see Briefing, keeping you up to date on the latest training courses, events and publications, and On the ground which provides helpful tips or updates on products relevant to land management.
CLM is published four times a year in March, June, September and December, and is available by subscription only, delivered straight to your door. Subscriptions start from £22 per year. Previous back issues are also available to purchase individually (subject to availability).
If you are involved in a conservation project and think your experiences could be useful to other practitioners, we would love to hear from you. If you are interested in writing for CLM feel free to contact us – we will be happy to discuss your ideas with you.