Pink Floyd’s Grantchester Meadows features some unusual instrumentation: the rolling whistles of a skylark, a honking goose, a buzzing insect. Recordings of blackbirds feature prominently in Kate Bush’s Aerial Tal, not to mention, of course, in the Beatles’ Blackbird, and field recordings of farmyard animals, rushing rivers and harsh winds have been used by other musicians over the years. Now, however, soundscape artists are blurring the division between music and the natural world further, with many taking to Britain's woodlands in search of their natural notes and melodies. For some, it’s not only a meditative experience, but a way of enhancing their perception of the natural world. “Listening, if you give it time, can be transformative to one’s sense of place,” sound artist Jez Riley French told Sound UK. “You have to give up control in a way. At least give up the idea that you know what a forest sounds like.” The quantity and variety of different sounds to be discovered in even a small patch of British woodland can be almost endless for the committed listener. Here are some you might not have noticed before: Caterpillar Business You may, on a June day, notice the sound of raindrops pattering on the forest floor, then look up to discover there’s not a cloud in the sky. When large numbers of caterpillars feed on the canopies of oak trees during early summer, a sound not unlike rainfall can be heard. This is actually the sound of frass (caterpillar droppings) landing on the forest floor. The Inner Workings of Trees This one requires a bit of specialist kit, but is worth the effort. By attaching a contact microphone to the trunk of a tree, you can record the whispering movement of water through the tree’s xylem and the crackling sound of the sap rising up the trunk during spring, as well as the tiny pops and cracks of the growing and shifting wood fibres. Wasps Taking a Bite Did you know wasps have a penchant for wood? Carefully approach a dry log or a bit of old fencepost on a summer’s day and you may hear a social or paper wasp hard at work. These wasps scrape away wood fibres, chew them into a pulp, and take them back to their nests to build new walls. The sound is a faint scrabbling, like fingernails on a tabletop. Gorse Bombshells  Some compare it to gunshots, though the more temperate say the sound is closer to popcorn. As the sun heats the seed pods of a gorse plant during summer, the pressure inside them gradually builds and eventually, they burst, launching their seeds into the air, and letting off a loud pop. When dozens are going off at once on a hot day, the sounds combine into a satisfying crackle. How to Have a Go Though a clutch of soundscape artists have made their passion into a profession by creating albums of natural sound or providing accompaniment to exhibitions, most use field recording as a relaxing weekend hobby, and an excuse to spend time in the woods. The price and complexity of recording setups can range depending on the user’s commitment.  Hobbyists might want to invest in an omnidirectional microphone, such as a Lom mikroUsi, a Clippy EM272, or a Sennheiser MKH 8020, in order to capture the entire forest atmosphere at once. Contact microphones that capture those gurgling tree sounds, or hydrophones for recording activity below the surface of ponds and brooks, can also be worthy investments for the truly dedicated.  But for those just starting out, a basic plug-in microphone or even a phone recording can provide a fine place to start. Often it is the act of paying acute attention to the woodland around you, rather than the recording itself, which is most valuable. “The key is to be aware of your individual role in the collective quietness,” French explained. “Allow time for the sounds to take us beyond our usual, short attention spans.” Thanks to David Alty for the wasp image.

The European hornet (Vespa crabo) is an eusocial insect.  That is to say, hornets live in colonies, with some 200 / 400 individuals in each colony.  A colony is founded by a fertilised queen, who emerges from hibernation in spring. Hornet queens are the sole survivors of an old colony after  a UK winter and they emerge as the weather finally starts to warm in early spring.  They then seek a warm, dry place to start nest construction. Once a nest location has been secured, they lay eggs that hatch into larvae.  The larvae are fed on protein-rich food (chewed up insects) and then they pupate; undergoing metamorphosis [a complete reorganisation of the body].  An adult hornet worker then emerges from the pupa some two weeks later.   These are ‘sterile’ female workers, who take over nest building and collecting food for the next set of developing larvae.   The developing colony lives within the papery nest its a (a bit like papier mâché), adding to the structure as the colony grows.  Twigs, bark and other plant material is broken up, chewed and shaped to form the nest. This material is glued together by their saliva.  Larvae that hatch in the summer are either fertile queens or males.  The males (drones) do not contribute to nest building, food foraging etc.  But in autumn, the males (drones) and the new queens leave the nest to mate.  The fertilised queens hibernate over winter, emerging in spring to start a new nest.  The ‘sterile workers’ and the male hornets die with the onset of winter. In other colonies of social insects, like honeybees, female workers don’t reproduce due to the pheromones that are released by the Queen. This was thought to be the case for European hornets but instead worker hornets enforce ‘sterility’ by physically destroying any worker-laid eggs or the workers laying them ! The food of a hornet is surprisingly varied. They can hunt and capture a wide variety of invertebrate prey (beetles, wasps, moths, dragonflies, robber flies - they may even prey on honey bees).  In many ways, hornets are useful in that they predate on a number of  garden and agricultural pests. Much of this prey is then chewed up to feed the growing larvae.  In return for this material, the larvae willingly ‘exude’ for the adults  a sugary liquid for them to feed on. Adults can also be found feeding on sugar-rich sources such as tree sap, nectar, and ripe fruit. They are more likely to ‘scavenge’ food at the end of summer into autumn rather than hunt.  The head of the insect has dark, prominent eyes, its wings are a reddish-orange, whilst the abdomen is striped with yellow and brown.  Hairs are present on both thorax and abdomen but they are not ‘hairy’ like bumblebees.  The colour of hornets can vary and a number of regional colour forms are known across Europe.  Worker hornets are about 25 mm in length, whilst queens may be up to 35 mm., so significantly bigger than wasps.  Partly because of its colour and size, a hornet can be mistaken for the Asian Giant Hornet (previously reported on in the woodlands blog).  However, a recent report indicates that the european hornet can attack and kill the Asian Hornet, by biting its head off.  Asian hornets are a considerable worry as they attack and kill  honey bees, plus their venom can induce life threatening anaphylactic shock. Breaking news : Asian hornets seen in Essex.   https://www.independent.co.uk/climate-change/news/asian-hornet-uk-bees-insects-b2177217.html In the past, the European hornet was rarely seen in the UK, being largely confined to areas of central southern England, but it has expanded in range in more recent times and is to be found across the South East and even in some more northerly locations.  Female hornets (but not males) have a stinger.  The venom within the stinger contains mixture of various neurotransmitters (serotonin, dopamine, histamine) as well as a concoction of enzymes.  Best avoided !  

The western honey bee (Apis mellifera) is the most common of the various honey bee species world-wide.  Like the other honeybee species, it is described as eusocial.  That is, thousands of sterile female worker bees live in colonies with one fertile queen, and a small number of males (drones).  The western honey bee is often described as a ‘domesticated’ insect. Whilst it is true the honey bees have been ‘managed’ by humans for thousands of years (through the provision of hives), their behaviour is essentiallysimilar to that of  their 'wild cousins’.  Read more...

Generally speaking, honey bees and bumblebees have a "good press", wasps do not.  Bees are associated with honey and the pollination of flowers and fruit trees.  Wasps are often associated with being stung and with disrupting our meals when dining "al fresco". Why is it that wasps want to invade our space and our meals?    Wasps, like bees, like sugary things (e.g. nectar).  During the Spring and Summer, wasps can obtain sugars from the larvae that they are rearing back in their nest. The worker wasps hunt for insects in our gardens amongst the flowers and vegetables, and take back their prey to the nest.  The prey is then fed to the larvae - which need a protein-rich diet in order to grow.   In return,  the larvae secrete (from their salivary glands) a sugar-rich fluid and the adults feed upon this. Read more...

Making woods resilient has become the latest fashion in forestry as illustrated by the RFS conference being organised with the Woodland Trust in Birmingham at the start of October.ˇ Resilience in this context means resilient both to diseases and to climate change effects.  Much of the thinking is based on the 2015 British Woodlands Resilience Survey which has been organised by the Sylva Foundation and sponsored by Oxford University, the RFS and the Woodland Trust.ˇ There have also been useful presentations on the subject such as the one given at the CONFOR Show (Confederation of Forest industries) show at Longleat, Wiltshire in early September 2015. Read more...

What is a plant gall?   As with most things, opinions vary but one of the definitive books on the subject by M. Redfern and R.R. Askew “Plant Galls” *offers the following description: “a gall is an abnormal growth produced by a plant under the influence of an organism ...... ; it involves enlargement and proliferation of plant cells which provide shelter and food for the gall maker.  Read more...

Not only do oak trees form part of our landscape but they also support an enormous range of organisms. Birds may make their nests in the canopy, spiders spin their webs in the twigs, squirrels gather the acorns, and many insects devour the leaves.  However, some insects make a home in the tissues of the trees and create new structures; these are called plant galls.  Read more...

The Turkey Oak (or Quercus cerris) is is a fast growing, tough tree; capable of surviving exposure in coastal regions. It was introduced as an ornamental tree into the UK in the eighteenth century,  being native to south east France across to the Balkans and Turkey.   It often has a long straight trunk (or bole), with branches that are somewhat more slender than those seen on English oaks. The leaves are distinctive and different from those of the native oaks (sessile or pedunculate). Whereas the leaf of the latter is quite broad, the leaf of the Turkey Oak is quite narrow and more ‘angular’ (see featured image);  it is also hairy or downy on its lower surface. One of the tree’s distinctive features is the bark, which has orange fissures near to the base of the trunk. Unfortunately, its timber is of little use as it splits and warps during seasoning. [caption id="attachment_37670" align="aligncenter" width="675"] Turkey oak bark[/caption] The Turkey Oak is considered by some to be a "weed species or pest species" because: it is fast growing it will hybridise with the English oak. it is a host to the Knopper Gall wasp Acorns form and mature some 18 months after pollination and are quite large. They may be an orange / brown at the base,  to a green-brown at the tip. The acorn 'cup' is 'hairy' (see image). The galls that form on the tree are abnormal growths.These galls are caused, in this case, by the development of wasp eggs within the plant’s tissues. The wasp (Andricus quercuscalicis) lays eggs in the catkins of the Turkey Oak, these hatch and develop into wasps which in turn lay their eggs in the flowers of the pedunculate oak. The acorns that form are grossly mis-shapen – and are called Knopper Galls. [caption id="attachment_40042" align="alignleft" width="150"] Gall[/caption] [caption id="attachment_40046" align="alignright" width="150"] Gall[/caption]       In some areas there are now systematic attempts to remove Turkey Oak and other non-native species from woodlands and forests.