A decoy (derived from the Dutch ''de'' ''kooi'', literally "the cage" or possibly ''ende kooi'', " duck cage") is usually a person, device, or event which resembles what an individual or a group might be looking for, but it is only meant to lure them. Decoys have been used for centuries most notably in game

hunting Hunting is the human practice of seeking, pursuing, capturing, or killing wildlife or feral animals. The most common reasons for humans to hunt are to harvest food (i.e. meat) and useful animal products ( fur/ hide, bone/tusks, horn/antler ...

, but also in

war War is an intense armed conflict between states, governments, societies, or paramilitary groups such as mercenaries, insurgents, and militias. It is generally characterized by extreme violence, destruction, and mortality, using regular o ...

time and in the committing or resolving of

crime In ordinary language, a crime is an unlawful act punishable by a state or other authority. The term ''crime'' does not, in modern criminal law, have any simple and universally accepted definition,Farmer, Lindsay: "Crime, definitions of", in Ca ...

Hunting

In hunting wildfowl, the term decoy may refer to two distinct devices. One, the duck decoy (structure), is a long cone-shaped

wickerwork Wicker is the oldest furniture making method known to history, dating as far back as 5,000 years ago. It was first documented in ancient Egypt using pliable plant material, but in modern times it is made from any pliable, easily woven material. ...

tunnel installed on a small pond to catch wild

duck Duck is the common name for numerous species of waterfowl in the family Anatidae. Ducks are generally smaller and shorter-necked than swans and geese, which are members of the same family. Divided among several subfamilies, they are a form ...

s. After the ducks settled on the pond, a small, trained dog would herd the birds into the tunnel. The catch was formerly sent to market for food, but now these are used only by

ornithologist Ornithology is a branch of zoology that concerns the "methodological study and consequent knowledge of birds with all that relates to them." Several aspects of ornithology differ from related disciplines, due partly to the high visibility and t ...

s to catch ducks to be ringed and released. The word ''decoy'', also originally found in English as "coy", derives from the

Dutch Dutch commonly refers to: * Something of, from, or related to the Netherlands * Dutch people () * Dutch language () Dutch may also refer to: Places * Dutch, West Virginia, a community in the United States * Pennsylvania Dutch Country People ...

''de Kooi'' (the cage) and dates back to the early 17th century, when this type of duck trap was introduced to England from the Netherlands. As "decoy" came more commonly to signify a person or a device than a pond with a cage-trap, the latter acquired the

retronym A retronym is a newer name for an existing thing that helps differentiate the original form/version from a more recent one. It is thus a word or phrase created to avoid confusion between older and newer types, whereas previously (before there were ...

"decoy pool". The other form, a

duck decoy (model) A duck decoy (or decoy duck) is a man-made object resembling a real duck. Duck decoys are sometimes used in waterfowl hunting to attract real ducks. Duck decoys were historically carved from wood, often Atlantic white cedar wood on the e ...

, otherwise known as a 'decoy duck', 'hunting decoy' or 'wildfowl decoy', is a life-size model of the creature. The hunter places a number about the hunting area as they will encourage wild birds to land nearby, hopefully within the range of the concealed hunter. Originally carved from wood, they are now typically made from plastic. Wildfowl decoys (primarily ducks, geese, shorebirds, and crows, but including some other species) are considered a form of

folk art Folk art covers all forms of visual art made in the context of folk culture. Definitions vary, but generally the objects have practical utility of some kind, rather than being exclusively decorative. The makers of folk art are typically tr ...

. Collecting decoys has become a significant hobby both for folk art collectors and hunters. The world record was set in September 2007 when a pintail drake and Canada goose, both by A. Elmer Crowell, sold for 1.13 million dollars apiece.

Military decoy

The decoy in war is a low-cost device intended to represent a real item of military equipment. They may be used in different ways: * deployed in amongst their real counterparts, to divert part of the enemy fire away from the real items of equipment. * for

military deception Military deception (MILDEC) is an attempt by a military unit to gain an advantage during warfare by misleading adversary decision makers into taking action or inaction that creates favorable conditions for the deceiving force. This is usually ac ...

, fooling the enemy into believing forces in a particular area are much stronger than they really are. One notable example are Quaker Guns. * to produce a multitude of false signals to overwhelm a radar or sonar defence system, such as

flare A flare, also sometimes called a fusée, fusee, or bengala in some Latin-speaking countries, is a type of pyrotechnic that produces a bright light or intense heat without an explosion. Flares are used for distress signaling, illumination, ...

s for IR-guided missiles or

chaff Chaff (; ) is the dry, scaly protective casing of the seeds of cereal grains or similar fine, dry, scaly plant material (such as scaly parts of flowers or finely chopped straw). Chaff is indigestible by humans, but livestock can eat it. In agri ...

for

ICBM An intercontinental ballistic missile (ICBM) is a ballistic missile with a range greater than , primarily designed for nuclear weapons delivery (delivering one or more thermonuclear warheads). Conventional, chemical, and biological weapons ...

Bomb decoy

irregular warfare Irregular warfare (IW) is defined in United States joint doctrine as "a violent struggle among state and non-state actors for legitimacy and influence over the relevant populations." Concepts associated with irregular warfare are older than the t ...

improvised explosive device An improvised explosive device (IED) is a bomb constructed and deployed in ways other than in conventional military action. It may be constructed of conventional military explosives, such as an artillery shell, attached to a detonating mechan ...

s are commonly used as roadside bombs to target military patrols. Some

guerillas Guerrilla warfare is a form of irregular warfare in which small groups of combatants, such as paramilitary personnel, armed civilians, or irregulars, use military tactics including ambushes, sabotage, raids, petty warfare, hit-and-run tac ...

also use imitation IEDs to intimidate civilians, to waste

bomb disposal Bomb disposal is an explosives engineering profession using the process by which hazardous explosive devices are rendered safe. ''Bomb disposal'' is an all-encompassing term to describe the separate, but interrelated functions in the milita ...

resources, or to set up an ambush. Some terrorist groups use fake bombs during a

hostage A hostage is a person seized by an abductor in order to compel another party, one which places a high value on the liberty, well-being and safety of the person seized, such as a relative, employer, law enforcement or government to act, or r ...

siege, in order to limit hostage rescue efforts.

Sonar decoy

A sonar decoy is a device designed to create a misleading reading on

sonar Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, measure distances ( ranging), communicate with or detect objects on ...

, such as the appearance of a false target.

In biochemistry

In biochemistry, there are decoy receptors, decoy substrates and decoy

RNA Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and deoxyribonucleic acid ( DNA) are nucleic acids. Along with lipids, proteins, and carbohydra ...

. In addition, digital decoys are used in

protein folding Protein folding is the physical process by which a protein chain is translated to its native three-dimensional structure, typically a "folded" conformation by which the protein becomes biologically functional. Via an expeditious and reproduc ...

simulations.

Decoy receptor

Decoy receptors, or sink receptors, are receptors that bind a

ligand In coordination chemistry, a ligand is an ion or molecule ( functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's ele ...

, inhibiting it from binding to its normal receptor. For instance, the receptor VEGFR-1 can prevent

vascular endothelial growth factor Vascular endothelial growth factor (VEGF, ), originally known as vascular permeability factor (VPF), is a signal protein produced by many cells that stimulates the formation of blood vessels. To be specific, VEGF is a sub-family of growth factors, ...

(VEGF) from binding to the

VEGFR-2 Kinase insert domain receptor (KDR, a type IV receptor tyrosine kinase) also known as vascular endothelial growth factor receptor 2 (VEGFR-2) is a VEGF receptor. ''KDR'' is the human gene encoding it. KDR has also been designated as CD309 ( clus ...

The

TNF inhibitor A TNF inhibitor is a pharmaceutical drug that suppresses the physiologic response to tumor necrosis factor (TNF), which is part of the inflammatory response. TNF is involved in autoimmune and immune-mediated disorders such as rheumatoid arthritis, ...

etanercept exerts its anti-inflammatory effect by being a decoy receptor that binds to TNF.

Decoy substrate

A ''decoy substrate'' or ''pseudosubstrate'' is a protein that has similar structure to the substrate of an

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. ...

, in order to make the enzyme bind to the pseudosubstrate rather than to the real substrate, thus blocking the activity of the enzyme. These proteins are therefore

enzyme inhibitor An enzyme inhibitor is a molecule that binds to an enzyme and blocks its activity. Enzymes are proteins that speed up chemical reactions necessary for life, in which substrate molecules are converted into products. An enzyme facilitates a s ...

s. Examples include K3L produced by vaccinia virus, which prevents the

immune system The immune system is a network of biological processes that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to parasitic worms, as well as cancer cells and objects such as wood splint ...

from phosphorylating the substrate eIF-2 by having a similar structure to eIF-2. Thus, the vaccinia virus avoids the immune system.

Digital decoys

In protein folding simulations, a decoy is a computer-generated protein structure which is designed so to ''compete'' with the real structure of the protein. Decoys are used to test the validity of a protein model; the model is considered correct only if it is able to identify the native state configuration of the protein among the decoys. Decoys are generally used to overcome a main problem in protein folding simulations: the size of the conformational space. For very detailed protein models, it can be practically impossible to explore all the possible configurations to find the native state. To deal with this problem, one can make use of decoys. The idea behind this is that it is unnecessary to search blindly through all possible conformations for the native conformation; the search can be limited to a relevant sub-set of structures. To start with, all non-compact configurations can be excluded. A typical decoy set will include globular conformations of various shapes, some having no secondary structures, some having helices and sheets in different proportions. The computer model being tested will be used to calculate the free energy of the protein in the decoy configurations. The minimum requirement for the model to be correct is that it identifies the native state as the minimum free energy state (see

Anfinsen's dogma Anfinsen's dogma, also known as the thermodynamic hypothesis, is a postulate in molecular biology. It states that, at least for a small globular protein in its standard physiological environment, the native structure is determined only by the pro ...

References

External links

Decoy Magazine, Joe Engers
- The ultimate publication for decoy lovers and collectors
The Midwest Decoy Collectors Association
– The de facto international collectors association

– Sir Ralph Payne-Gallwey, 1886 (full text)
British Duck Decoys of To-Day, 1918
– Joseph Whitaker (full text) {{Authority control Hunting equipment Penetration aids