Biggest Bird Ever
The biggest birds ever to have lived were the extinct Madagascar Elephant Birds. Fossil records show they weighed 500 kg (1,120 lb) and were over 3 m (10 ft) tall. The Elephant Birds became extinct three hundred years ago. The Giant Moa (Dinornis maximus) was the tallest bird ever found. It was over 3.7 m (12 ft) high.
Largest Living Bird
It is the Ostrich (Struthio camelus). The bird can reach heights of 2.7 m (9 ft). It can weigh up to 156 kg (345 lb). The Ostrich also produces the biggest eggs in the world. A single Ostrich egg weighs 1.4 kg (3 lb).
Other Large Extinct Birds
The extinct Dromornis stirtoni of Australia were among the biggest birds ever, as their dimensions were almost the same as the Madagascar elephant birds. The Dromornis stirtoni belonged to the mihirungs group of the Dromornithidae family.
The Brontornis was the biggest carnivorous bird to have ever lived. A flightless bird, its remains were found in South America. It was 2.8 m (9 ft 2 in) high and weighed 350 to 400 kg (770 to 880 lb).
The largest bird that could fly was the Argentavis magnificens. It weighed 80 kg (175 lb) and was 3 m (10 ft) long. The wingspan reached 8.3 m (28 ft).
Other Large Living Birds 
The heaviest flying birds are the Kori Bustard or paauw (Ardeotis Kori) of southern and northeast Africa. It weighs about 42 lbs. The European Great Bustard (Otis tarda) has the same weight.
The Andean Condors are the biggest living birds of prey. They have a wingspan of at least 10 feet and weigh from 20 to 27 lbs. There is a preserved male California condor (Gymnogyps californianus) that once weighed 31 lbs.
Longest Bill
It belongs to the Australian pelican (Pelicanus conspicillatus. It is 13 to 19.5 inches in length. In terms of body relation, the longest would belong to the Sword- Billed Hummingbird (Ensifera). Its four inch beak is longer than its body.
Biggest Wingspan
It belongs to the Wandering Albatross (Diomedea exulans). A male specimen has a wingspan 11 ft. 11 in. The bird was captured in the Tasman Sea on 1965 September. The biggest nests belong to the Mallee Fowl. It is 35 feet wide, 15 feet high and weighs 330 tons.
There are reports of much larger birds, but none of these sightings have been confirmed. However, diggings are still ongoing, so the biggest bird ever may yet to be uncovered.
