The speculum is a patch, often distinctly coloured, on the inner remiges of some birds.

Examples of the colour(s) of the speculum in a number of ducks are:

• Common Teal
  Common Teal
  The Eurasian Teal or Common Teal is a common and widespread duck which breeds in temperate Eurasia and migrates south in winter. The Eurasian Teal is often called simply the Teal due to being the only one of these small dabbling ducks in much of its range...
  
   and Green-winged Teal
  Green-winged Teal
  The Green-winged Teal is a common and widespread duck that breeds in the northern areas of North America except on the Aleutian Islands. It was considered conspecific with the Common Teal The Green-winged Teal (Anas carolinensis) is a common and widespread duck that breeds in the northern areas of...
  
  : Iridescent green edged with buff.
• Blue-winged Teal
  Blue-winged Teal
  The Blue-winged Teal is a small dabbling duck from North America.-Description:The Blue-winged Teal is long, with a wingspan of , and a weight of . The adult male has a greyish blue head with a white facial crescent, a light brown body with a white patch near the rear and a black tail. The adult...
  
  : Iridescent green. The species' common name comes from the sky-blue wing coverts.
• Crested Duck
  Crested Duck
  The Crested Duck is a species of duck native to South America, the only member of the monotypic genus Lophonetta. It is sometimes included in Anas, but it belongs to a South American clade that diverged early in dabbling duck evolution . There are two subspecies: L...
  
   and Bronze-winged Duck
  Bronze-winged Duck
  The Bronze-winged Duck also known as the Spectacled Duck, is a dabbling duck and the sole member of its genus Speculanas. It is often placed in Anas with most other dabbling ducks, but its closest relative is either the Crested Duck or the Brazilian Duck, which likewise form monotypic genera...
  
  : Iridescent purple-bronze, edged white.
• Pacific Black Duck
  Pacific Black Duck
  The Pacific Black Duck is a dabbling duck found in much of Indonesia, New Guinea, Australia, New Zealand, and many islands in the southwestern Pacific, reaching to the Caroline Islands in the north and French Polynesia in the east. It is usually called the Grey Duck in New Zealand...
  
  : Iridescent green, edged light buff.
• Mallard
  Mallard
  The Mallard , or Wild Duck , is a dabbling duck which breeds throughout the temperate and subtropical Americas, Europe, Asia, and North Africa, and has been introduced to New Zealand and Australia....
  
  : Iridescent purple-blue with white edges.
• American Black Duck
  American Black Duck
  The American Black Duck is a large dabbling duck. American Black Ducks are similar to Mallards in size, and resemble the female Mallard in coloration, although the Black Duck's plumage is darker...
  
  : Iridescent violet bordered in black and may have a thin white trailing edge.
• Northern Pintail
  Northern Pintail
  The Pintail or Northern Pintail is a widely occurring duck which breeds in the northern areas of Europe, Asia and North America. It is strongly migratory and winters south of its breeding range to the equator...
  
  : Iridescent green in male and brown in female, both are white on trailing edge.
• Gadwall
  Gadwall
  The Gadwall is a common and widespread duck of the family Anatidae.- Description :The Gadwall is 46–56 cm long with a 78–90 cm wingspan. The male is slightly larger than the female, weighing on average 990 g against her 850 g...
  
  : Both sexes have white inner secondaries.
• Yellow-billed Duck
  Yellow-billed Duck
  The Yellow-billed Duck, Anas undulata, is a 51–58 cm long dabbling duck which is an abundant resident breeder in southern and eastern Africa.This duck is not migratory, but will wander in the dry season to find suitable waters...
  
  : Iridescent green or blue, bordered white.

Bright wing speculums are also known from a number of other birds; among them are several parrots from the genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 Amazona with red or orange speculums, though in this case the colors are pigmentary and non-iridiscent.