Author: Poppy Dean

How Can We Use Sound to Measure Biodiversity? – Webinar Round-up

In July, the Biological Recording Company held the first of three webinars on bioacoustics in conservation. These webinars, which are presented in partnership with Wilder Sensing, Wildlife Acoustics and NHBS, began with a general introduction to bioacoustics, and will be followed with two sessions later in the year discussing the technology in more detail. 

In the first webinar, talks by Geoff Carss of Wilder Sensing and Joe Hampson from the Somerset Wildlife Trust provided listeners with an overview of bioacoustic technology, its applications in measuring diversity and a short story of Honeygar farm, the Trust’s first ‘wilded’ site. NHBS are pleased to have sponsored this webinar, and we would like to thank participants who took part in our prize draw to win a Song Meter Micro 2. 

Wilder Sensing: An entry-level introduction to bioacoustics 

Bioacoustics provides ecologists and conservationists with an auditable, low-cost technology to measure biodiversity. It involves the use of audio recorders to passively detect sound in an environment, which can then be analysed to provide insights into community assemblage.   

This technology can be used to measure several environmental variables, including animal presence, soil health, weather and infrastructure. Long-term monitoring of an environment can provide us with new insights on the richness and species density of an area and can even be used to analyse migration of key groups. Analysis can also determine areas of interest and habitat preferences for certain species, which can be used to inform future land management.  

This method removes bias from traditional surveying techniques, where the skill and age of the observer, or sometimes even the day itself, can impact the result of a traditional survey. However, there are some limitations associated with this technology. False positives (the technology can misidentify a species), false negatives (the technology might miss a call), poor sound quality and mimicry can impact the accuracy of recorded data. To capture an accurate picture of community assemblage, passive recording is best used in partnership with traditional site surveying. This way, disturbance and false negatives can be mitigated, and through bioacoustic surveys, we can revisit the recordings as technology develops.  

An acoustic sensor deployed at Honeygar Farm. Image by Wilder Sensing.

Key points:  

  • Bioacoustic technology provides additional insights into community assemblage through the use of sound  
  • The technology is best used alongside traditional surveying for a more accurate overview 
  • The technology is limited by sound quality, false positives and false negatives. 

 

Somerset Wildlife Trust: Honeygar Farm Case study 

Honeygar Farm is an 81-hectare site of former intensive farmland, now owned by the Somerset Wildlife Trust (SWT). Since acquiring Honeygar, SWT have employed a unique ‘wilded’ approach to restoring the site. 

Changes in hydrology management were among the biggest alterations at Honeygar, as the site has been subject to intense peat drainage to make way for agriculture. Honeygar has over two metres depth of peat, equivalent to 100,000 tons of carbon dioxide, so restoring the natural peatland by blocking drainage ditches was key to improving the carbon storage on site. Cutting and grazing by cattle, historically a huge pressure, has also been reduced from a herd of around 140 animals to 40 individuals. This, partnered with limited silage cutting and resting fields from grazing, is encouraging recovery of the botanical communities on site. The Trust is also exploring the use of different ungulates, including goats, ponies and different cow breeds, to better support the wetland habitat.  

Over 20 months, nearly 13 million records were gathered using four sensors on site. This monitoring was undertaken alongside breeding bird, wintering bird and breeding wader surveys to provide a more detailed picture of community assemblage, confirmed with manual validation and targeted surveys to assess rare bird presence. Honeygar will continue to be monitored for insects, birds, mammals, fungi and plants to inform future management practices. 

Speaker Joe Hampson deploying acoustic recorders on site. Image by Wilder Sensing.

Key points: 

  • Honeygar Farm is the Trust’s flagship site for the ‘wilding’ approach 
  • Formerly an agricultural farm, Honeygar is being restored to its natural peatland habitat through alterations in landscape management 
  • Bioacoustic technology has provided insight into the community assemblage at the farm, helping to inform landscape management.  

This webinar was an enlightening insight into bioacoustics and highlighted some interesting points on its conservation applications. Read our Q&A with Geoff to hear more about Wilder Sensing and its technology, and find more details on Honeygar on the Somerset Wildlife Trust website.  

Find tickets for the next webinar, ‘Can Passive Acoustic Monitoring of Birds Replace Site Surveys?’ here. 

The NHBS Guide to UK Common Garden Beetles

Beetles are insects that form the order Coleoptera, meaning ‘sheath-winged’. They get their name from the adaptation of their front wings which have formed tough protective cases called elytra.  This gives them an armour-like appearance while protecting the delicate wings underneath.  

As one of the most diverse groups across the world, there are over 400,000 species – more than 4,000 of these can be found in the UK. In this post we will look at some of Britain’s beetles, detailing their key features and where to find them.  

 Rose Chafer (Cetonia aurata)  

Rose Chafer by Hedera Baltica via Flickr

Conservation status: Common 

Distribution: Widespread across the UK, but scarce in number. Most common in southern England. 

Identification: This large beetle is instantly recognisable by its iridescent emerald green carapace. Up to 2cm long, this broad beetle will often have white streaks across its wing case, which can occasionally appear purple or bronze in colour. The underside is covered in fine, pale hairs and there is an obvious ‘V’ shape on its back where the wing cases meet. 

Where to find them: Grassland, woodland edges, scrub and farmland. Rose Chafers can also be found in towns and gardens, where they are considered a pest. You can find them between May and October when they can be spotted in sunny weather.  

  

Cock Chafer (Melolontha melolontha) 

Image by Frank Vassen via Flickr

Conservation status: Common 

Distribution: Widely distributed across the UK, more common in the south of England. 

Identification: The UK’s largest scarab beetle, the Cock Chafer can grow up to 4cm in length. It has rusty brown wing cases with a black body and brown legs. Its underside is covered in fine, pale hairs and it has a pointed tail. It has distinctively large, fan-like antennae that can be used to distinguish the sex – males have seven feathers and females have six. 

Where to find them: Meadows, farmland, grassland, woodland, heath and moorland, and gardens from April to July. These insects are mostly seen after sunset, where they can be found near streetlights and bright windows.  

 

Stag Beetle (Lucanus cervus) 

A large, black and maroon coloured beetle standing on a piece of wood.
Image by Ben Sale via Flickr

Conservation status: A globally threatened species, the Stag Beetle is listed as a priority species in Schedule 5 of the Wildlife and Countryside Act 1981.  

Distribution: Nationally scarce. This species is mainly found in south-east England. It is most abundant in the Thames Valley and Hampshire and is locally common in some areas of the south-west.  

Identification: A spectacular insect, the Stag Beetle is recognised for its antler-like mandibles. Males can grow up to 8cm, while the females grow to 5cm and have smaller mandibles. Both have a shiny black head, thorax and legs with chestnut-coloured wing cases.  

Where to find them: They can be found from mid-May to late July in woodland, hedgerows, parks and gardens. Although usually found on the ground, males can be seen in flight during sunset on hot summer evenings.  

 

Lesser Stag Beetle (Dorcus paralellapipidus) 

Image by Guy-F via Flickr

Conservation status: Common 

Distribution: Found throughout England and Wales. 

Identification: Smaller than their threatened cousins, the Lesser Stag Beetle grows up to 3cm in length and can be distinguished by smaller mandibles and knobbed antennae. Although similar in shape and colour, this species has a broad head and matt black wing cases.  

Where to find them: Hedgerows, woods, farmland, grassland, towns and gardens from May to September. They can often be found basking in the sun on tree trunks and can be seen flying near bright lights at night. 

 

Rosemary Beetle (Chrysolina americana) 

Image by Katja Schulz via Flickr

Conservation status: Common 

Distribution: Widespread in the UK, particularly in south-west England. Distribution is patchier in Wales, Scotland and Northern Ireland.  

Identification: A small, shiny beetle growing up to 1cm in length, the Rosemary Beetle is a striking metallic green with orange and purple stripes. The head and thorax are mostly green with some red markings, and the legs are a brown-red.  

Where to find them: Rosemary Beetles are found year-round but are commonly spotted between April and September. The species is closely associated with Lavender, Thyme and Rosemary. 

 

Wasp Beetle (Clytus arietis) 

Image by Frank Vassen via Flickr

Conservation status: Common 

Distribution: Widespread across the UK, less common in Scotland.  

Identification: A narrow-bodied longhorn beetle, this species has a long, black body with yellow horizontal stripes. The Wasp Beetle has short brown antennae and brown legs. 

Where to find them: Wasp Beetles can be found in farmland, woodland, hedgerows, parks and gardens between April and July.  

 

Red Soldier Beetle (Rhagonycha fulva) 

Image by Hedera Baltica via Flickr

Conservation status: Common 

Distribution: Widespread in the UK. 

Identification: Growing up to 1cm in length, the Red Soldier Beetle is small and narrow. It has a rectangular body that is a vibrant orange red with black tips to the wing cases. Their orange legs are tipped with black feet and they have long antennae.  

Where to find them: This species can be found from June to August, usually on open-structured flowers such as daisies and Cow Parsley, in grasslands, hedgerows, woodland, parks and gardens.  

 

Red-headed Cardinal Beetle (Pyrochroa serraticornis) 

Image by Frank Vassen via Flickr

Conservation status: Common 

Distribution: Widespread in England and Wales. 

Identification: A mid-sized beetle growing up to 2cm in length, the Red-headed Cardinal Beetle has a vibrant orange-red head and wing case. Its legs and antennae are black, the latter long and toothed.  

Where to find them: Adults can be found in woodland, hedgerows, farmland, parks and gardens from May to July. 

 

Devil’s Coach Horse Beetle (Staphylinus olens) 

Image by Frank Vassen via Flickr

Conservation status: Common 

Distribution: Widespread in the UK. 

Identification: The Devil’s Coach Horse, easily recognised by its scorpion-like stance when threatened, is a medium-sized black beetle growing up to 3cm in length. It has large, powerful jaws and a long, thick abdomen. The body is covered in fine black hairs and the wing cases are very short.   

Where to find them: Devil’s Coach Horse Beetles can be found from April to October in hedgerows, grassland, farmland and gardens. They require damp living conditions and are often found under stones and in compost heaps. 

 

Violet Ground Beetle (Carabus violaceus) 

Image by Guy-F via Flickr

Conservation status: Common 

Distribution: Widespread in the UK. 

Identification: Growing up to 3cm in length, the Violet Ground Beetle has a distinctive metallic violet colouring running along the edge of a black thorax and smooth wing cases.  

Where to find them: Violet Ground Beetles can be found from March to October in woodland, grassland, moorland and urban areas. They are frequently found under logs and stones.   

This Week in Biodiversity News – 5th August

Environment  

The number of plastic bags found on beaches has reduced by 80%. Since mandatory charges were introduced in the UK, data recorded by the Marine Conservation Society’s annual litter survey has recorded a marked decrease in the number of bags found on UK beaches –  last year the survey recorded an average of one plastic bag every 100m, down from five in 2014.  The discovery has led to calls for action to further reduce other types of marine litter.  

A single diver swimming across a bed of bleached coral. The coral is very branched, and pale white.
Coral Bleaching. Image by The Ocean Agency/XL Catlin Seaview Survey/Richard Vevers via Flickr

The world’s reefs are in the middle of the most widespread heat event since records began. After 18 months of record-breaking temperatures, reefs in over 70 countries have been impacted and over 73% of reefs have experienced temperature extremes high enough to initiate bleaching. This event is the second recorded in the last ten years and is the fourth global coral bleaching event on record. Reef conservationists and researchers are urging the scientific community to rethink ways to tackle these events, and are calling for the redoubling of efforts to reduce other stressors on reef habitats.  

 

Discoveries 

Chimpanzees have been observed turn-taking during conversation. Researchers have followed five groups of Eastern Chimpanzees (Pan troglodytes schweinfurthii) in Tanzania and Uganda, recording the chatter between groups. The team recorded over 8,500 gestures used in back-and-forth conversation, finding a response time of around 200 milliseconds – the same time as observed in humans. Gestures involve hand flicking to shoo others away and stretching of hands to ask for food. Researchers believe that, in this species, gestures do the talking, while facial expressions and vocalisations add tone to the conversation.  

A chimpanzee is resting its hand under its chin. It is looking thoughtfully towards the sky with the sun on its face
Image by Vanessa via Flickr

Brazilian wild sharks have tested positive for cocaine. Previous studies have found traces of cocaine in rivers, seawater, wastewater, and smaller marine organisms such as shrimp and mussels, causing serious toxicological effects. However, the concentration observed in Rio’s sharks is around a hundred times higher than other animals testing positive for this substance. The contamination source is currently unknown but is thought to have originated from losses during shipment or the dumping of narcotics to evade authorities. Particularly worrying, the Brazilian Sharpnose Sharks (Rhizoprionodon lalandii) analysed in this study are a component of the Brazilian diet, and it is not yet known how this contamination could impact humans. 

 

Conservation  

A near extinct species of crocodile is making encouraging progress in Cambodia. In June, sixty Siamese Crocodiles (Crocodylus siamensis) hatched, following the discovery of five nests in May; a rewarding result from nearly two decades worth of conservation efforts in the Cardamom mountains. Once widespread, these animals have been subject to hunting and habitat loss, resulting in their classification as critically endangered . Since 2012, a collaborative programme by local officials and Fauna & Flora has successfully released nearly 200 individuals, helping to maintain the global population which currently sits at around 400. 

A large, black crocodile is laying on the floor in a patch of bark surrounded by small plants
Image by tontantravel via Flickr

Butterfly numbers in the UK are the lowest on record. An unusually wet spring and summer has dampened mating opportunities for butterflies across the country, resulting in a dramatic decrease in populations. With populations still struggling to bounce back from 2022’s drought, the wettest spring since 1986 has further prevented butterfly recovery across the country. Populations are at the lowest recorded since Butterfly Conservation’s Big Butterfly Count began 14 years ago, and as a key indicator species for habitat health, the findings are particularly troubling for the wider environment.

There has been a surge in ‘starving’ bats in Britain. Conservation groups have reported an increase in malnourished, underweight bats and fewer individuals overall for this time of year. A wetter-than-average spring and summer have negatively impacted insect, butterfly and moth populations, resulting in a blow to food sources for these animals. With nursing mothers unable to feed their young, volunteer organisations caring for bats are also seeing a surge in admissions. 

Grey long eared bat flying with wings spread at night with leaves in the background
Grey Long-eared Bat via iStock

 

The NHBS Guide to UK Solitary Bees

There are around 270 bee species in the UK, and over 90% of these are solitary – they do not nest in colonies, do not produce honey and don’t have a queen. Instead, these bees lead solitary lives, only coming together to mate. The group can be divided into ground-nesting species, found on lawns, paths and loose soil, or aerial nesters which utilise hollow plant stems, dead wood and man-made bee hotels to build a nest for larval bees. 

Here we look at a small selection of these important pollinators found in the UK, outlining ways in which they can be identified and where they can be found.  

Mason Bees 

Mason bees is the name used to refer to bees of the genus Osmia. There are around 500 different species of mason bee across the world, and around 20 of these can be found in the UK. This group gets their name from their use of mud or clay in nest building, which takes place in naturally occurring gaps or cracks, and other small, dark cavities. Some species of mason bee will also use hollow stems or bore holes made by wood-boring insects.

Red Mason Bee (Osmia bicornis)  

Two small, orange bees are sat on a head of purple flowers. One is sat on top of the other bee.
Osmia bicornis by Tim Worfolk, via Flickr.

Distribution: Widespread and common throughout England and Wales. Rarer in Scotland. These bees can be found from early spring in grassland, farmland, towns and gardens. Red Mason Bees are common in built environments and are often seen nesting in the crumbling mortar of old walls. This species is also a common inhabitant of bee hotels.

Identification: These fluffy bees grow up to 1.1cm long and are typically identified by dense, gingery hair. On both males and females, the head and thorax are brown with an orange abdomen. Males are typically smaller than their female counterparts and have a distinctive white tuft of hair on the head. Female Red Mason Bees have dense orange hairs on the abdomen, with pollen collecting hairs on the underside. This species also has a pair of short, distinct horns on the head.

 

Red-tailed Mason Bee (Osmia bicolor) 

Red Tailed Mason Bee on a wooden fence with four holes drilled in it.
red tailed mason bee by Nick Goodrum, via flickr.

Distribution: Nationally rare in the UK. Red-tailed Mason Bees can be found from March to July in the south and east of England and south Wales. This species occurs exclusively on calcareous grassland over chalk or limestone, in quarries, grassland and brownfield sites.  

Identification: This species has dense, black hair on the head and thorax. Bright orange-red hair is present on the abdomen and the lower legs, forming stripes of orange and brown on the upper abdomen. Males are slimmer and less vibrant than females, and can have pale, duller brown hairs on their head, thorax and abdomen.

 

Mining Bees 

Sometimes referred to as digger bees, this group are named after their burrowing behaviours in which they create their nests. There are roughly 65 species in the Andrena genus, making mining bees the largest bee genus in Britain.

Tawny Mining Bee (Andrena fulva)

A female tawny mining bee on a leaf.
A female Tawny Mining Bee (Andrena fulva) by Lukas Large, via flickr.

Distribution: Widespread and common in England and Wales. Populations are growing in Scotland. This species can be found in farmland, heathland, parks, towns and gardens from March to June.

Identification: Similar in size to a honeybee, with dense orange hair and a black face. Females tend to be larger and have a thick, orange coat covering the upper thorax and abdomen. The underside is covered with black hair, along with the head and legs. Males are trickier to identify but are generally smaller and slimmer. They have long mandibles and are browner in colour, but can be distinguished by white tufts of facial hair on the head.

 

Ashy Mining Bee (Andrena cineraria)

Ashy Mining Bee on a ribbed, green leaf.
Andrena cineraria by Tim Worfolk, via flickr.

Distribution: Common and widespread across Britain and Ireland. Can be found nesting in gardens, woodlands, riverbanks and urban environments from March to July. 

Identification: A distinctive bee growing up to 15mm in length. Females have two, broad grey bands at the top and bottom of the thorax. The abdomen is sparsely haired, revealing a glossy black exoskeleton and the legs are covered with dense black hair. They also have a patch of ashy grey hair on their faces. Males have similar markings but are generally smaller in size. The bands are less distinct, and they have a spread of grey hair across their thorax. 

Leafcutter Bees

Named for their nesting habits, these bees are known to cut circular leaf pieces to use as building material for their nests. Leafcutter bees lay their eggs in natural tree cavities where they use up to 40 pieces of harvested leaves and petals to create a chamber for safe incubation. There are seven different species of leafcutter bee in the UK – they can be found nesting in beetle holes, plant stems, deadwood, cliffs or old walls.

Patchwork Leafcutter Bee (Megachile centuncularis) 

Megachile centuncularis harvesting pollen from a pink flower.
Megachile centuncularis by Gilles San Martin, via flickr.

Distribution: Widespread and common throughout the UK, although less common in the north. Patchwork Leafcutter Bees can be found in a range of habitats from April to August, including grassland, farmland, woodland, towns and gardens. This species is strongly associated with willowherbs, honeysuckle and roses.  

Identification: Easily identified by the vibrant yellow-orange pollen brush under the abdomen, extending right to the tip. This species is a similar size to honeybees, growing up to 13mm. The female has defined white bands across the abdomen. Males are more challenging to identify – similar in appearance to a dark honeybee, with the characteristic vibrant underside and tan coloured hair around their thorax.

 

Willughby’s Leafcutter Bee (Megachile willughbiella) 

Megachile willughbiella female bee on the petal of a pink flower.
Megachile willughbiella female by Line Sabroe, via flickr.

Distribution: Common and widespread across Britain. Frequently observed in brownfield sites from June to August. This species is also readily found in bee hotels.

Identification: Up to 18mm in size, Willughby’s Leafcutter Bees are similar in appearance to Patchwork Leafcutter Bees. They appear similar to dark honeybees, with little hair. The species varies in shades of black, with orange and gold throughout the coat and an orange pollen brush. Males can be distinguished by oversized front basitarsi, giving the appearance of white, wooly mittens.

The NHBS Guide to UK Shore Crabs

A charismatic highlight of any rock-pooling session, crabs are both diverse and wonderful. Here we have a selection of the most common crabs in the UK, detailing their habitats and how to identify them. 

Velvet Swimming Crab (Necora puber) 

Image by Guy F via Flickr

Conservation status: Common, non-threatened. 

Where to find them: The species is widespread throughout the UK and can be found year-round on rocky shores at low water. They are found more frequently on sheltered shores and prefer rocky substrates.  

Shell Width: Up to 10cm.  

ID: Also known as the devil crab, the Velvet Swimming Crab has short hairs covering its body, giving the animal a velvety appearance. The crab is blue in colour, but is covered by a reddish-brown pubescence masking the overall hue – they do, however, have visible blue lines on their legs, and blue tips on their claws. The carapace is flattened and has five pointed ridges on either side of the eyes. A fast-moving and aggressive crab, it has distinctive, bright red eyes that give it its alternative name. Pincers are of equal size, and the rear legs are flattened to be used as paddles.  

 

Edible Crab (Cancer pagurus) 

Image by Guy F via Flickr

Conservation status: Common, non-threatened. 

Where to find them: Edible Crabs can be found year-round on rocky shores across the UK. The species is often found hidden under rocks and boulders but can also be found on mixed coarse ground and on muddy sand offshore.  

Shell width: 10-25cm, averaging around 15cm.  

ID: A large species, the Edible Crab is also known as the brown crab for its colour – they can be brown to reddish-brown, bearing white patches and young specimens can have a purple-brown carapace. They have a thick, oval-shaped shell with a distinctive ‘pie crust’ edge. Also recognised by the black tips to their claws.  

 

Spiny Spider Crab (Maja brachydactyla)  

Image by Guy F via Flickr

Conservation status: Common, non-threatened. 

Where to find them: Spiny Spider Crabs, also known as European spider crabs, can be found from January to December on rocky areas. They are common on the south and west coasts, but are largely absent from northern England, Scotland and the North Sea.  

Shell width: Up to 20cm. 

ID: Known to be the largest spider crab in Britain and Ireland, they are instantly recognisable for their long legs resembling a spider. They have a distinctively spiky carapace, often covered with algae giving it a hairy, green appearance. The shell has an oval shape, broader at the back and narrower at the front. It has longer, more pronounced spines on the border of the shell, and the rest is covered by smaller spines. They are mostly orange in colour, but have been found in red, yellow or brown varieties.  They have two distinct frontal spines which are sandwiched by two small eyes. The legs are covered in hair, with the first pair bearing small claws.  

 

Common Hermit Crab (Pagurus bernhardus) 

Image by Guy F via Flickr

Conservation status: Common, non-threatened. 

Where to find them: Common Hermit Crabs can be found year-round on rocky shores and sandy substrates along the UK coast. They are most easily found in rock pools at low tide, particularly after storms and turbulent weather, where they can be dislodged and are more easily visible.  

Shell width: Varies according to body size, which can measure up to 4cm in length. 

ID: The largest and most common of the 15 hermit crab species, these crabs live inside the empty shells of sea snails, commonly whelks and periwinkles. Their body is reddish-brown in colour, with a larger right pincer. Their claws are strong, and are covered in uniformly distributed granules, with two rows of larger granulations starting at the base of the claw, converging towards the middle. The species is associated with Calliactis parasitica, a sea anemone which lives on their shell in a symbiotic relationship.  

 

Shore Crab (Carcinus maenas) 

Image by Guy F via Flickr

Conservation status: Common, non-threatened. 

Where to find them: Shore Crabs are found year-round in rockpools. They may also be found while crabbing in shallow waters and are particularly abundant in estuaries and salt marshes.  

Shell width: Up to 9cm. 

ID: The species is slightly green in colour, but can also be found with orange and red carapaces and yellowish spots on the abdomen – varied colouration can be attributed to life cycle stages, and juvenile Shore Crabs specifically can have significant variance in colour. The broad carapace has five teeth on each side of the shell, and three scalloped lobes between the eyes.  

 

Masked Crab (Corystes cassivelaunus)  

Image by Guy F via Flickr

Conservation status: Common, non-threatened. 

Where to find them: A small burrowing crab, the Masked Crab can be found buried in sandy substrates on the lower shore. They are found along most of the British coastline and are particularly abundant in the south and west of the UK. 

Shell width: Up to 4cm. 

ID: Masked Crabs have an elongated oval carapace with long antennae, often the size of their body. Their colour can range from reddish brown to yellow and the lateral margin of the carapace has four distinct spines. The claws are twice the length of the carapace, although females have smaller pincers.  

 

Broad-clawed Porcelain Crab (Porcellana platycheles) 

Image by Guy F via Flickr

Conservation status: Common, non-threatened. 

Where to find them: Can be found January to December across the UK, although with sporadic distribution. They can be found under rocks and small boulders on rocky shores.  

Shell width: 1.5–1.8cm. 

ID: A small crab covered with long hairs, the Porcelain Crab can be grey to greenish-brown with an off-white underside. They have large, broad front claws that appear to be slightly flattened and two long antennae. The fifth pair of legs are smaller and often concealed, resulting in the illusion of only three pairs of walking legs. Due to its size and impressive camouflage, this species can be hard to spot.  

It can be truly fascinating to sift through rock pools, finding the weird and wonderful creatures that our environment has to offer, but it is important to remember best practices when investigating our wildlife. To look for crabs safely, approach them from behind to avoid pincers, opt for a net for safe retrieval and hold the crab firmly, without squeezing, to ensure that it does not fall whilst handling. When you are finished, remember to leave everything where you found it, replace any rocks that you may have turned over during your search and return crabs to the same body of water you found them in.  

The NHBS Guide to Thistles

Distinctively prickly with pink or purple flowers, thistles belong to the largest family of flowering plant in the UK (with the exception of the grasses) – Asteraceae. These common plants are found throughout Britain and Ireland, providing key services for invertebrates who seek safety in the sharp spines. The leaves and nectar of thistles are also excellent sources of food for other groups, including pollinators and Painted Lady caterpillars, and several bird species are known to eat the seeds.

Here we take a look at a selection of thistles found throughout the UK, highlighting their distribution and ways in which they may be identified.  

 Creeping Thistle (Cirsium arvense)  

Creeping Thistle by hedera.baltica via Flickr

ID Notes: This perennial flower is named for its far-reaching, creeping roots. The leaves are smooth and grey-green in colour, with wavy, spined edges. The stems are smooth, neither spined nor winged. The flowerheads produce small, pale pink flowers (1.5–2.5cm) in small clusters with pear-shaped bases covered with phyllaries pressed against the flowerhead, curving outwards.  

Distribution: Widespread and common throughout Britain and Ireland. Creeping Thistles can be found from June to October on rough grassland, roadside verges and field edges – a preference for disturbed and cultivated ground is observed in this species.  

 

Spear Thistle (Cirsium vulgare) 

Spear Thistle by Andreas Rockstein via Flickr

ID Notes: This thistle is particularly attractive to pollinators, who are often seen feasting on the deep pink flowers. The large flowerheads (up to three may be present per stem) sit on a bulbous, spiked base with long, spreading phyllaries. The leaves of a Spear Thistle have long, lanceolate segments tipped with spines, and the upper surface is bristly. The stem is covered with light hair and sporadic spiny wings.  

Distribution: Widespread and common throughout Britain and Ireland. It can be found from July to October on disturbed ground such as roadside verges, field edges and pastures.  

 

Welted Thistle (Carduus crispus) 

Welted Thistle by Joost J. Bakker IJmuiden via Flickr

ID Notes: This plant has small, red-purple flowerheads that are clustered together. The base of the flower head has spiny, protruding bracts and the phyllaries project outwards. The branched stems have several rows of spiny wings, and the leaves have broader lobes than is typical for other thistles, with spiny margins. 

Distribution: Widespread throughout Britain, except Ireland. This species shows a preference for nutrient-enriched substrates, including brownfields, field margins, meadows and beside streams.  

 

Marsh Thistle (Cirsium palustre) 

Marsh Thistle by Gertjan van Noord via Flickr

ID Notes: Growing up to 2m in height, this large thistle is easily identified by its purple tinge. The flowerheads are small and are found in large clusters, with small reddish-purple or white flowers and the phyllaries are pressed against the flower head, with tips facing downwards. Leaves are more slender and shorter, with hair visible on the upper surface, they are often tinged purple on the margins and have many spines.  

Distribution: Widespread throughout Britain and Ireland, and can be found in marshes, damp grassland and meadows. 

 

Meadow Thistle (Cirsium dissectum) 

Meadow Thistle by Thibault Lefort via Flickr

ID Notes: Each Meadow Thistle has one flower head on a cottony stem, growing up to 80cm tall – the solitary flower has purple-tipped, long bracts and the base covered with light, white hair. The stems are not winged, and basal leaves are toothed in a rosette formation. The remaining leaves are finely toothed, without spines, and have light hair on top, with a white, cottony appearance underneath.

Distribution: Most common in the south of the UK, with strongholds in the south-west and south Wales. Meadow Thistles are scarce towards the north. They can be found in bogs, fens, grassland and meadows.  

 

Musk Thistle (Carduus nutans) 

Musk Thistle by Sam Thomas via Flickr

ID Notes: Growing up to 2m in height, the Musk Thistle is recognised for its greyish-green colour. The flowerheads are large (3–5cm across), often nodding to one side after maturity, and have long, spiny phyllaries and two-lipped petals. The leaves are short and twisted, with spines present on the toothy lobes and are often woolly underneath.  

Distribution: Widespread throughout Britain, but absent from Scotland and Ireland. Most commonly found on calcareous soil from May to September.  

 

Woolly Thistle (Cirsium eriophorum) 

Woolly Thistle by Olive Titus via Flickr

ID Notes: The Woolly Thistle gets its name from its wool-like covering. The leaves are ladder-like and narrow, tipped with spines and are white underneath. The stems are wingless and are covered in cobweb-like hairs, producing a single large flowerhead. The phyllaries on the flower base are downward curved, spread throughout the cobwebbing.  

Distribution: Widespread throughout Britain, with strongholds in the Yorkshire Wolds and the Isle of Wight. The ‘queen of thistles’ often prefers chalky soils.  

 

 

The NHBS Guide to Clovers

Often perceived as a pesky weed in garden lawns, clovers are low-growing, common plants belonging to the family Fabaceae – also home to beans, peas and legumes. These drought resistant plants can be found throughout Britain and Ireland in a range of habitats and are key food sources for a number of pollinators.  

Here we look at a selection of clovers found in Britain, highlighting their identifying characteristics and where they can be found.  

White Clover (Trifolium repens) 

A view of clovers in the grass. Lots of small, white flowers tower above a bed of circular leaves
White Clover by Andreas Rockstein via Flickr

ID Notes: A familiar ‘weed’ of grassy spaces, the White Clover is easily recognised for its distinctive trefoil leaves – three leaflets bearing white markings. The flowers are white, sometimes pink toward the tips, with rounded heads made of many tubular blooms. Left to grow, this plant can grow up to 40cm in height, and is associated with Common Blue Butterflies (Polyommatus icarus) and bumblebees.  

Distribution: Common and widespread throughout Britain and Ireland. This plant can be found in grassy areas from May to October, including gardens, roadsides, meadows and parks.  

 

Red Clover (Trifolium pratense) 

A pink clover, made of multiple smaller flowers, takes a globular shape. It is surrounded by three hairy leaflets with a lighter 'v' shape in the middle
Red Clover by Judy Gallagher via Flickr

ID Notes: Similar to White Clovers, this species has three green leaflets bearing white markings, often ‘V’ shaped. The rounded flower heads bear pink/red flowers, forming clusters that are 2–3cm across. 

Distribution: Common and widespread throughout Britain and Ireland. This species will flower from May to October, and can be found in gardens, meadows, parks and roadsides. It is also sown as a fodder crop for livestock, so can be found in open pasture.  

 

Strawberry Clover (Trifolium fragiferum) 

On the left is a baby pink flower, the bottom half of it is more brown in colour and is dying. On the right is a pale pink fruit, it looks like a raspberry with a swollen, knobbly exterior
Strawberry Clover by Mark Gurney via Flickr

ID Notes: The Strawberry Clover has a densely packed flower head, brimming with pink-red pea-shaped flowers that turn darker throughout the growing season. The leaves have three leaflets, and the fruit resembles a pale raspberry. 

Distribution: Common in the south-east of England, it is found both inland and at the coast. Throughout Wales and northern England, this plant is mostly found coastally. Strawberry Clover can be found in fields, gardens, grassland, woodland and rocky areas.  

 

Hares-foot Clover (Trifolium arvense) 

A white fluffy flower on a hairy stem with hairy leaves.
Hare’s-foot Clover by hedera.baltica via Flickr

ID Notes: These pale pink flowers (2–3cm in size) are covered with small soft hairs giving it a cottony appearance, like a hare’s paw, as the name would suggest. The trifoliate leaves are divided into three leaflets, narrower than other clovers and covered in fine hair. The stalks are also covered in fine, white hair.  

Distribution: Fairly common in England and Wales, with a preference for coastal areas. Hares-foot Clover is uncommon in Scotland and Ireland. It can be found from June to September in dry grasslands, meadows, sandy soils and coastal areas.  

 

Knotted Clover (Trifolium striatum) 

A cylindrical shaped clover, with red veins in the base of the flower head. the leaves have three leaflets and are slightly pink on the edges
Knotted Clover by Thibault Lefort via Flickr

ID Notes: Up to 15mm across, the flowers of a Knotted Clover form pale pink (or white), ovoid flowerheads. The leaves are hairy on both sides and are divided into three toothed leaflets. This clover is easily distinguished by the knotting visible along the stem.  

Distribution: Widespread throughout Britain. Mostly found flowering at coastal sites between May and July, it can be found on beaches, fields, grassland, meadows, roadsides and sand dunes. 

 

Zigzag Clover (Trifolium medium) 

A bright, purple clover. the flower is made of multiple smaller flowers, and the leaves are more pointed with a light edge.
Zigzag Clover by Nina Laakso via Flickr

ID Notes: A dense flowerhead up to 3.5cm across, the Zigzag Clover is similar to the Red Clover, except that it has darker, reddish-purple flowers and spreading flowerheads. The leaves are longer and narrower, with less hair than other clovers and the stem is distinctively zigzagged allowing for easy identification.  

Distribution: Common in England, Wales and Scotland, except the far north. Zigzag Clover can be found from May to July in gardens, grassland, roadsides and verges, often on poor soil.  

 

Crimson Clover (Trifolium incarnatum) 

A bumble bee on a vibrant red pear-shaped flower.
Crimson Clover by Gerard Meyer via Flickr

ID Notes: This plant produces dense, conical-shaped heads of vibrant red flowers. The blooms of Crimson Clover are very attractive to bees, forming a close association in spring and summer. The stem and leaves are hairy, the latter composed of three leaflets.  

Distribution: Not commonly seen in Britain. This species is mostly found from May to September in grasslands, gardens, cliffsides and meadows in the south of the UK.  

 

This Week in Biodiversity News – 15th July

Environment 

Global temperatures have hit 1.5°C above the pre-industrial era average for 12 consecutive months. Analysed by the Copernicus Climate Change Service, data revealed that July 2023 – June 2024 were the hottest 12 consecutive months on record – an average 1.64°C higher when compared to the pre-fossil fuel era (1850–1900). Analysis suggests that these results are not an anomaly but are instead consistent with a shift in the global climate.  

Ranking of annual average surface air temperatures in 2023. Image by Copernicus Climate Change Service

A court has ruled that the rights of the Machángara river have been violated in Ecuador. The ruling was based on constitutional rights for natural features, where Ecuadorian authorities recognise the rights of natural features to remain unpolluted and undegraded.  A wide range of contaminants and pollutants are released into the river, including untreated wastewater and litter, resulting in an average oxygen content of 2% which has inhibited the survival of aquatic life in the region. Although the ruling has been appealed by the city government, the court has ruled that a remediation plan will be required. 

Science  

Researchers have identified artificial light on coastlines as another threat for marine ecosystems. A study has shown that artificially lit areas can attract 2–3 times more fish compared to areas of natural lighting. It is thought that juvenile fish are attracted to congregations of plankton in these well-lit areas and are picked off by predators who are also attracted to the light. Nearly a quarter of the world’s coastline was artificially lit when it was last surveyed almost a decade ago, and the extent of the lighting is likely to have continued to increase since then. This issue has the potential to impact the breeding success of a range of marine species.  

A marine port at night time with bright artificial lights illuminating the area, including the water
Image by Martin Garrido via Flickr

Ants have been found to amputate the legs of their nest-mates to boost survival. Researchers have found that Florida Carpenter Ants (Camponotus floridanus) will perform life-saving amputations on others, the first non-human animal found to do so. The colony was also found to cater their choice of care to the injury at hand and were observed ‘treating’ injuries through intensive licking. Ultimately, a survival rate of 90% was observed following amputation, and 75% with treated wounds. These ants are one of the few animals, aside from humans, that have been found to actively tend to the injuries of their own species. 

For the first time, we are farming more seafood through aquaculture than we catch from the wild. The 2024 State of World Fisheries and Aquaculture (SOFIA) report was released in June and reported that overfishing increased and sustainable fishing declined over 2024 (+4% and –2%, respectively), while overall production rose by over 4%, producing an all-time high of 223 million metric tons of fish. The SOFIA report concluded that progress towards more sustainable fisheries is not moving fast enough, or has regressed to less sustainable practices, and global fisheries management is failing to support these practices when harvesting wild fish stocks.

Wildlife                                                              

Bee colonies in north east England are suffering from the worst disease outbreak in a decade. American Foulbrood (AFB) has been reported in more than 30 colonies in a 10km area, the biggest outbreak since 2014. The disease is caused by bacteria that infect the bee larvae, eventually spreading through the hive and resulting in the death of the colony. A spokesperson from the Cleveland Beekeepers Association has labelled the outbreak as ‘worrying’ but believes the disease is under control.  

A bull moose with large antlers standing in scrub
Bull Moose by Denali National Park and Preserve via Flickr

Human-wildlife conflicts are emerging in Colorado as Moose (Alces americanus) populations extend their range. Introduced to the state in the 1970’s, Moose are now moving into more urban areas from the woodlands and mountain ranges across the state, increasing the frequency of deadly human-wildlife conflicts. The number of recorded Moose attacks each year surpasses the number of puma and bear attacks combined, though Moose are less abundant in the area. Colorado reported three incidents in a fortnight in 2022, and over 59 animals were killed in road traffic accidents that same year. At risk of reaching unsustainable levels, the species could be subject to culling and contraceptive intervention in the future to prevent damage to the landscape and its keystone species.  

 

Going to Bat for Bioacoustics: How Acoustic Monitoring is Helping to Save Bats – Webinar Round-up

Recently, Wildlife Acoustics and Bat Conservation International partnered together to host a webinar highlighting the use of bioacoustics in bat conservation across the globe. The webinar featured three case studies tackling the impacts of white-nose syndrome, habitat loss and climate change with the help of bioacoustic technology. Here, we provide a summary of these case studies and the applications of acoustic monitoring in these investigations. 

Florida USA, Dr. Melquisedec Gamba-Rios 

Endemic to the region, the Florida Bonneted Bat (Eumops floridanus) is increasingly threatened by habitat loss from sea level rise and destructive development. This species has one of the smallest ranges in Southern Florida and utilises old tree cavities and large, open spaces for roosting and feeding. Dr. Gamba-Rios and his team sought to identify critical habitat for this endangered species using bioacoustics, hoping to support their fragile populations.  

The team used acoustic recorders to identify key roosting and feeding areas for the species. Interestingly, they found that Miami’s zoo, golf courses and tropical parks had high numbers of Florida Bonneted Bat calls. The research showed that the large, open areas surrounded by forest and absence of artificial light of these locations provided an ideal foraging space for the species. 

Since these bats require older, cavitied trees, the habitat of the group is at risk as development increases. Plans for water park construction were proposed on a key site for this species, however the evidence gathered here was used to challenge the proposal, resulting in its rejection to protect key bat habitat. In March 2024, over 1.1 million acres of critical habitat were designated for the species in Florida, including foraging areas in urban habitat and over 4,000 acres of Miami Pine Rocklands. Federally protected species are known to be twice as likely to move toward recovery than those without protection, so the designation of these spaces is incredibly important in securing the future of this species.  

Shows a small brown bat with closed eyes, it is held in a blue blanket in daylight
Florida Bonneted Bat by Florida Fish and Wildlife via Flickr

Nyungwe National Park, Dr. Jon Flanders 

Last seen in 1981, the Hill’s Horseshoe Bat (Rhinolophus hilli) was considered a ‘lost’ species in Rwanda.  In January 2019, a group of scientists and researchers, including Dr. Jon Flanders, set out on a 10-day expedition in Nyungwe National Park, looking to rediscover this elusive animal.  

Nyungwe National Park rangers played a key role in the early stages of this project, identifying caves and key habitat for bats in the area. The rangers conducted acoustic monitoring using SM4 Acoustics to identify foraging and roosting areas, collecting over 260,000 files of acoustic data. Eight of these recordings successfully detected the calls of the Hill’s Horseshoe Bat, found in small, defined ranges. During the 10-day trip, the team worked relentlessly to catch, measure and collect DNA samples from bats using mist nets and harp traps in these locations. The team successfully captured two Hill’s Horseshoe Bats and confirmed the capture of this critically endangered species with museum archive specimens. The expedition highlighted the spectacular diversity of Nyungwe National Park which features a large number of rare and endemic species, and these findings reinforce the parks importance as a biodiversity hotspot.

A brown bat is hanging upside down. it has white fluffy mould covering its wings and face
Little Brown Bat with white-nose syndrome by U.S. Fish and Wildlife Service via Flickr

White-nose Syndrome, Dr. Amanda Adams 

White-nose syndrome is a cold-loving, infectious fungal disease found in bats. The fungus manifests in a total skin infection, most visible around the muzzle of the animal. This infection is responsible for significant mortality in several species, where the infection causes bats to wake often during hibernation – burning their fat stores, causing dehydration and starvation. Infected bats can expend up to twice the amount of energy as healthy individuals during hibernation, severely impacting their ability to survive the winter. Because of this, six million animals have succumbed to this infection so far, impacting 12 out of 44 species found in the USA.  

Dr. Amanda Adams sought to use bioacoustics to enhance the management of foraging habitat to support these species through hibernation. The team used the Song meter mini to search for the presence of bats and observe their feeding behaviours. They found that feeding behaviours were observed up to three times more in prey patches, and this allowed researchers to designate feeding habitats for affected species. The survey will be used to inform vegetative management on passing corridors, aiming to increase the productivity of foraging areas to support the health of infected bats.  

The ‘Going to Bat for Bioacoustics’ webinar provided an engaging insight into the applications of acoustic monitoring in bat research, showing how the technology can be used to support bat conservation. To learn more, the Wildlife Acoustics website has a range of training courses and webinars. Upcoming events can be found here.  

 

This Week in Biodiversity News – 1st July

Environment 

An ocean-dwelling fungus has been found to break down marine plastic pollution. Parengyodontium album has recently been added to the list of four species of plastic degrading fungi. Researchers have discovered the fungus’ ability to degrade polyethylene plastic, the most abundant form of plastic in our oceans, following a period of exposure to UV radiation from sunlight. It is estimated that the fungus can break down polyethylene at a rate of 0.05% each day, and with over 400bn kilograms of plastic produced annually, this discovery has the potential to provide an answer to the problem of marine plastic pollution.

Image by Papahanaumokuakea Marine National Monument via Flickr

A recently launched programme will aim to restore a 193km stretch of coral reef. Named ‘Ako’ako’a, the project will be one of the first to attempt such large-scale restoration and will focus this effort on the west coast of Hawai’i Island. Due to start in 2025, researchers will identify individuals with desirable traits in the face of climate change, such as high thermal tolerance, fast growth and tolerance to pollution. These selected individuals will then be used to produce larvae with strengthened genetic resistance which will be released during natural spawning periods. With increasing declines occurring over more frequent bleaching events, ‘Ako’ako’a aims to restore ailing reefs across the region.  

 

Conservation 

Canada is set to ban open-net salmon farming in British Columbia in five years. The announcement follows the government’s decision to transition to closed-containment methods in 2019. With more than half of wild salmon stocks declining in the province, the decision has been made to make a step towards protecting wild pacific salmon populations through sustainable aquaculture and clean technology. The commitment has been praised by many, but there are concerns for significant losses in a $1.2bn industry and disruptions impacting up to 6,000 jobs.  

Iberian Lynx are no longer endangered under the IUCN Red List of Threatened Species. Lynx pardinus has been promoted to ‘vulnerable’, a triumph resulting from a 20-year conservation programme by the EU, national governments in Spain and Portugal and wildlife NGOs. The population initially plummeted to under 100 individuals due to human persecution, reduced food sources and habitat loss across the region. Now, 20 years later, the population has reached over 2,000 in the peninsula. Over 86% of the current population resides in Spain and experts expect to see a full recovery in its native range over the next century. 

A pale rhino laying down on a bed of grass next to a tree
Northern White Rhino by Heather Paul via Flickr

Scientists have successfully implanted a rhinoceros embryo using IVF techniques for the first time. This breakthrough could prove to be a lifeline in saving the Northern White Rhinoceros from extinction. There are only two surviving females in the world, both based in Ol Pejeta Conservancy in Kenya where they are under 24-hour guard. Proving the feasibility of the technology, researchers can now move to transferring a Northern White Rhinoceros embryo into a surrogate Southern White Rhinoceros. This technology brings the scientific community closer to successfully reproducing this critically endangered species, which would significantly benefit the ecosystem of central and eastern Africa.  

 

Wildlife 

The first Scottish Wildcat kittens born outside of captivity have been recorded in Cairngorms national park. Their birth follows the reintroduction of 19 adult wildcats last summer and has been confirmed using camera trap footage. This discovery marks an important milestone in the efforts to reintroduce the species to Scotland, and they are the first to be born in the wild for more than five years. With significant population declines due to habitat loss and human persecution, this success story is an important turning point for the species and will help to reverse centuries of decline.

A scottish wildcat walking across a fallen tree in the woods
Scottish Wildcat by Chris Parker via Flickr

A subgroup of Gray Whales has undergone a significant decline in body length in the past 20-30 years. The Pacific Coast Feeding Group (PCFG), consisting of around 200 individuals, have decreased in size over the past 20-30 years. Researchers found that the group is 13% smaller than those born before 2000, which equates to around 1.65 metres lost in a mature adult. This smaller size could have significant consequences for the health and fecundity of the group, impacting survival rates of calves and their ability to store energy for growth and maintenance.