Grui has within its umbrella so many bird families, from the Gruiformes, to the Suborder Ralli, which has quite a number of extinct and living birds having some very few things in common. For instance, the Gruiformes are diverse in terms of morphology and geography and are very widespread.

The traditional classification manner had it that many terrestrial and wading families of birds that were unique from any other type of order ended up being classified as Gruiformes. Within this included around 14 large crane species and other 145 rails and crakes small species and other diverse bird families of a couple of species, from the Limpkin, trumpeters to the Heliornthidae. So many birds have ended up being placed within this group out of the sheer necessity of placing them somewhere making such an order as Gruiforme to lack a distinctive trait. Most ‘odd Gruiformes’ are related loosely to rails, cranes and their relatives (realistic Gruiformes).

Other birds making this group are cranes, which are long-legged and long-necked, large birds that also find themselves within the Gruiformes order. Real cranes are about 15 species. A crane flies with the neck outstretched and they are found within all continents except South America and Antarctica.

The cranes and other types of birds within the Grui group have very distinct and elaborate feeding patterns, largely making them opportunistic feeders, something that gives them the ability to change their own diet as per the season and the requirements in terms of nutrients. They are known to feed on a wide variety of food items, from fish, rodents, amphibians, plants, berries, grains to insects.

Most of the Grui birds have extensively displayed courting noises or what is sometimes known as dances, mostly the cranes. Folklore has depicted that most of these birds mate for life, but research has shed light to the fact that the birds usually change mates in the course of their lives.

In terms of migration, most species within the Grui are known to migrate over very long distances while others hardly migrate. Large populations of cranes are known to migrate, since they are very gregarious with the quality of forming very formidable flocks with sufficient numbers.

Other families of birds within the wider Grui include the trumpets, restricted to the Amazon forests or such South American basins as the Orinoco. The trumpets or cackling is specifically a menace call from males. These are dumpy birds with legs and necks very long sporting curved bills as well as a clear hunched posture. As much as their heads are quite small, the eyes are substantially large and seem like ‘good natured’ birds.

Their plumage is quite soft with traits of velvet or fur on their necks and head. It has iridescences of green, bronze and purple as much as it is mostly black, largely on the lower neck and wing coverts. Their tertial and secondary flirt feathers have hues of gray, white, black with shades of green falling on their lower backs, where the colors distinguish the different species.