Dove

Doves are birds seen minimally in the How to Train Your Dragon Book series.

Description
Doves are birds belonging to the Family Columbidae, along with pigeons. In fact 'Dove' and 'Pigeon' can be used interchangeably and do not designate specific groups within Family Columbidae.

Doves are fairly short-legged birds with small beaks and a bobbing gait. They are perhaps the most numerous Family of birds worldwide at present, but many species are threatened with extinction or are already extinct. The Passenger pigeon was one of the most numerous species in the 1800's living in North America. However, heavy hunting for food by humans completely wiped out their species by the early 1900s. The Dodo bird is actually a member of the Family Columbidae as well, and is a famously extinct bird due to human activity.

Interestingly, doves and pigeons are one of the few bird groups that produce "pigeon milk" or "crop milk". Though bird milk may serve a similar function as the milk produced by mammals, it is not actually milk. These birds produce special fat and nutrient-filled cells in their crops that slough off and are regurgitated to feed chicks.

Some species historical Vikings may have encountered include the stock dove (Columba oenas), the common wood pigeon (Columba palumbus), and the European turtle dove (Streptopelia turtur).

Diet
Doves and pigeons are primarily herbivores, though some species also feast on insects and other invertebrates. Of the herbivorous species, pigeons and doves can be divided into grain and seed eaters and fruit eaters. Of the species that eat other animals, diet may include insects, worms, snails, or even small reptiles

Function
Doves are seen as entertainment in How to Speak Dragonese.

In reality, in addition to use in entertainment, doves and pigeons have been used for many millennia as a method of communication between people. Small notes and even very small objects were tied to a "carrier pigeon" and released, so that it would fly back to its home. Doves and pigeons are extremely adept at finding their way back to their roosts.

Doves and pigeons have also been consumed by many cultures around the world for millennia. The hobby of keeping pigeons and doves as pets and showing has also been around for quite awhile, historically.

How to Speak Dragonese
The Romans at Fort Sinister put on a public show for Saturn's Day Saturday, called "Survival of the Fittest". The first portion of the event involves releasing a flock of rainbow-dyed doves into the wire-enclosed arena. Soon after, a pack of Sidewinder dragons are also released into the arena, whom are hungry and quickly eat all the doves.