Black Powder: The type of explosive used to power a Cannon Net.
Cable (otherwise known as Firing cable or Main cable): A wire running from the Firing box to the Dropper enabling the net to be fired when required.
Cannon: Device for ejecting a projectile attached to a Cannon Net in order to throw the net safely over the birds. Powered by a Cartridge loaded in to the base of the Cannon. Four cannon are required for a 'full' net, two for 'half' or 'mini' nets.
Cannon Net (sometimes referred to as Full net, Mini-net, Half-net etc): The net used to catch the birds.
Projectiles are attached to the Leading Edge of the net and fired from the Cannons, over a flock of birds at rest on the ground beneath. A typical 'Full Net' is 27m long by 13m wide. See How We Catch Birds
Cannon Net Licensee: A person who has had the necessary extensive training and experience to hold a licence necessary to operate cannon netting equipment, and lead a team in its safe and efficient use.
Cartridge:The explosive charge loaded in each cannon to eject the Project when the net is fired. The cartridge itself is a reusable stainless steel container, loaded with a small charge of Black Powder, detonated by an electric fuse and sealed with a wad. Cartridges inserted in Cannons are connected by the dropper and cable to the firing box.
Clap Net Pair: A pair of cannon nets set opposite each other in such a way that when fired the forward (or Leading) edge of the nets will just meet.
Colour Rings: Small coloured plastic rings, fitted in additional to the numbered metal ring, enabling more detailed studies of bird populations for specific projects. They enable sightings of individual birds to be made using binoculars or telescopes, without the need to recapture the birds. This method has been used with considerable success in recent studies of Turnstone feeding strategies on The Wash, and in establishing the movements and origins of Black-tailed Godwit; a species which has only appeared in large numbers on The Wash since the early 1990's.
Control: A bird originally ringed elsewhere, or during a previous migration, and subsequently re-caught on The Wash.
Decoy: A range of plastic and stuffed birds of various species which are placed in or near the catching area in such a way as to encourage other birds to land with them.
Dropper: A wire connecting all the cannons required to fire a single net together so that all cannons fire simultaneously. The Dropper is connected via the Firing Cable to the Firing Box.
Firing Box: The device which when the Cannon Net Licensee decided it is appropriate fires the net. This is done by delivering a high voltage current via the Firing cable and dropper to detonate the fuses in the Cartridges which in turn ejects the projectile from the cannons and hence launches the net over the birds.
Firing Position: The position from which the Cannon Net Licensee observes and decides when to fire the net. The firing position, normally in a hide and directly in line with the furled net(s), is sited to give a maximum view of the catching and safety areas.
Furling the net: Gathering of the cannon net netting into a loose roll, which is placed just in front of the cannons, ready for firing.
Furled net: The state of the netting once Furling is complete.
Grockles: An affectionate term for passers-by... where necessary spoken to by the Long-stop.
Grot: Typically seaweed, or other vegetation, spread lightly over a Furled net so as to disguise or blend it into the setting environment.
Hide: A hessian tent-like construction within which typically 2-4 people can be close to the catching area but remain concealed from view. A 'Fensman' hide used by the Group is a one-man hide.
Jiggler: A length of chord, with small hessian flags (or ‘Jiggles’) attached, that is set along the length of the safety area. The Jiggler can, when necessary during the catching process, be gently moved back and forth to persuade any bird settling in the safety area to move, without necessarily disturbing birds in the catching area. This, unfortunately, isn't as easy as it sounds!
Jump-Ropes: Ropes attaching the net pegs to the net. These ropes stop the back edge of the net from moving forward, and are of such a length that the back edge of the net lands forward of the safety area (since no birds will be in this area when firing... see Safety Area)
Keeping box: A wooden box into which birds are placed when removed from the net in order to transport them safely to the keeping cages.
Keeping cage: Place where birds removed from nets are kept safely prior to ringing and processing. Keeping Cages are portable tunnels of hessian or cotton, set into soft ground over a hessian base.
Leading Edge: The front edge of a cannon net as it is fired.
Long-stop: A team member positioned so as to prevent inadvertent disturbance of a catching attempt by walkers or beach-goers, and offer information on the Group's activities etc. Typically used when catching on or near sea walls or in beach locations.
Mist net, Mist net pole: A fine mesh-netting, suspended vertically between bamboo poles, and typically set over pools on the saltmash. See How We Catch Birds. Because waders have very good eyesight this method only really works when it is totally dark, and mist-netting attempts have to be carefully planned for evenings when the tide is high enough for the mudflats to be covered, but not so high that the saltmarsh pools are swamped or become inaccessible.
Net Peg: Pegs securely set along the back of a cannon net to which the Jump Ropes are attached so that the net can extend fully out in front, before coming to rest over the catching area.
Net Zero: Nets are normally set in lines, often one or two nets, sometimes up to four. For reference when catching, net one is the net nearest the firing position. When reference is made to birds being in net zero, this means birds have landed in an area which is one net length closer to the firing position than the net that is set (i.e. not catchable!). Similarly net five is the imaginary net one net length beyond net four.
Projectile: A metal weight connected to the net by Trace Ropes. The projectile is then inserted in the cannon. When the net is fired, the projectile is ejected out of the cannon, thus carrying the Leading edge forward and unfurling the net behind it.
Recce: Reconnaissance; in order to establish where the birds favour landing, and indeed on which sites, team members are deployed solely to gather this information ready for subsequent catching attempts.
Recovery: A bird ringed on The Wash and found or caught elsewhere.
Ringing and Processing: In some countries Ringing is known as Banding; a small metal ring equivalent in weight to a wristwatch on a human, is placed securely on the leg of each bird caught. The ring sizes are individually tailored for different sizes of birds legs. Each ring bears a unique number, so that if it is caught subsequently it can be identified individually. Processing involves taking detailed measurements and information about the birds plumage, condition and weight.
Safety Area, In Safety: Because a cannon-net is set on the ground, there is an area immediately in front of the nets that would be dangerous for any bird to be standing in when the net is fired. For this reason this area is carefully measured out relative to the angle at which the net has been set (using angle gauges). Under no circumstances is the net fired when any bird is in the safety area (or 'in safety'), even if it means a catch can't be made. A Jiggler is used to try and clear any bird in the safety area prior to firing. Similarly there must be no persons or property in line with the front of the nets when firing; although a negligible risk, if a projectile was to break free from the net this would be extremely hazardous. Cannon-netting is always carried out with paramount safety of birds and people.
Tape Lure: Recordings of wader calls played through a sound system close to mist nets to encourage birds to approach the netting area.
Trace Ropes: The ropes connecting the leading edge of the cannon net to the projectile. Usually three or four to each projectile.
Twinkle, Twinkling: The process whereby a person or vehicle slowly approaches a flock of waders which are not in the catching area, in order to induce them to walk or fly into the desired area. Occasionally, also used to remove birds from the Safety area. This is also not as easy as it sounds!
Ush: The process of carefully placing a cannon net and arranging growing vegetation around and over it to conceal it.
Waders: In some countries waders are known as shorebirds. Waders are also thigh length boots which are worn by team members in preference to wellington boots when cannon-netting on the waters edge, or when mist-netting!
WeBS counts: Monthly Wetland Bird Survey counts are carried out by numerous volunteer counters around the Wash, (and other estuaries), organised by the BTO, RSPB and Wildfowl and Wetlands Trust.