Wagtail

The wagtails form the passerine bird genus Motacilla. They are small birds with long tails which they wag frequently. Motacilla, the root of the family and genus name, means moving tail. The forest wagtail belongs to the monotypic genus Dendronanthus which is closely related to Motacilla and sometimes included herein.

The willie wagtail (Rhipidura leucophrys) of Australia is an unrelated bird similar in coloration and shape to the Japanese wagtail. It belongs to the fantail flycatchers.

Characteristics

Wagtails are slender, often colourful, ground-feeding insectivores of open country in the Old World. They are ground nesters, laying up to six speckled eggs at a time. Among their most conspicuous behaviours is a near constant tail wagging, a trait that has given the birds their common name. In spite of the ubiquity of the behaviour and observations of it, the reasons for it are poorly understood. It has been suggested that it may flush up prey, or that it may signal submissiveness to other wagtails. Recent studies have suggested instead that it is a signal of vigilance that may aid to deter potential predators.

Wagtail (missile)

The Wagtail missile, also known as "Wag Tail", was a short-range nuclear missile developed in the late 1950s by Minneapolis-Honeywell under a contract awarded by the United States Air Force. Intended for use as an auxiliary weapon by bomber aircraft, the missile was successfully test fired in 1958, but the program was cancelled in the early 1960s.

Design and development

The Wagtail project was initiated in 1956, with Minneapolis-Honeywell being contracted to develop a short-range, solid-rocket-powered missile. The missile would be armed with a low-yield nuclear warhead, and was intended for use as a tactical support missile by supersonic aircraft engaged in low-level attacks.

The Wagtail missile was intended to be fitted with a guidance system that utilised an inertial navigation system and a terrain-following radar, which allowed the missile to be fired from and navigate at extremely low altitudes. The missile was equipped with small retrorockets that retarded the missile following release, allowing the launching aircraft the opportunity to escape the blast wave from the missile's warhead.