A list of the world's most Evolutionarily Distinct and Globally Endangered (EDGE) species has been revealed after scientists from the Zoological Society of London (ZSL) and Yale University assessed the world's 9,993 bird species.
They whittled down their findings to a definitive list of the top 100 most endangered and unusual birds.
The giant ibis (Thaumatibis gigantea) topped the list. It's a big one, weighing over 4kg and at over a metre in height. Only 230 pairs remain in the wild, making it critically endangered.
The majority of the birds on the list are receiving hardly any or no conservation action as hunting and loss of habitat threaten them.
Carly Waterman, Edge programme manager at ZSL, said: "We lament the extinction of the dodo, but without action we stand to lose one of its closest relatives, the tooth-billed pigeon or 'little dodo', and many other extraordinary birds.
"The release of the Edge birds list enables us to prioritise our conservation efforts in the face of a mounting list of endangered species. These one-of-a-kind birds illustrate the incredible diversity that exists in our natural world."
The world's top 100 most unusual and endangered birds are:
1.Giant Ibis
2.New Caledonian Owlet-nightjar
3.California Condor
4.Kakapo
5.Kagu
6.Bengal Florican
7.Forest Owlet
8.Philippine Eagle
9.Christmas Island Frigatebird
10.Sumatran Ground-cuckoo
11.Spoon-billed Sandpiper
12.Northern Bald Ibis
13.Plains-wanderer
14.New Zealand Storm-petrel
15.Hooded Grebe
16.White-shouldered Ibis
17.Maleo
18.Black-hooded Coucal
19.Madagascar Serpent-eagle
20.Dwarf Olive Ibis
21.Rufous Scrub-bird
22.Noisy Scrub-bird
23.Junin Grebe
24.White-collared Kite
25.Congo Bay-owl
26.White-eyed River-martin
27.Red-headed Vulture
28.Secretarybird
29.Peruvian Diving-petrel
30.Egyptian Vulture
31.St Helena Plover
32.Australian Painted Snipe
33.Cuban Kite
34.Tooth-billed Pigeon
35.Nahan's Francolin
36.Sulu Hornbill
37.Shoebill
38.Purple-winged Ground-dove
39.Asian Crested Ibis
40.Sangihe Shrike-thrush
41.Jerdon's Courser
42.Lesser Florican
43.Kokako
44.Rufous-headed Hornbill
45.Masked Finfoot
46.Bahia Tapaculo
47.Waved Albatross
48.Stresemann's Bristlefront
49.Sociable Lapwing
50.Eskimo Curlew
51.Slender-billed Curlew
52.Bannerman's Turaco
53.Ashy Storm-petrel
54.Siberian Crane
55.White-throated Storm-petrel
56.Juan Fernandez Firecrown
57.Dark-winged Trumpeter
58.Uluguru Bush-shrike
59.Polynesian Ground-dove
60.Sichuan Jay
61.Mountain Serpent-eagle
62.Sulu Bleeding-heart
63.Zapata Rail
64.Mindoro Bleeding-heart
65.Kaka
66.Negros Bleeding-heart
67.Black Stilt
68.Makira Moorhen
69.Great Indian Bustard
70.Abbott's Booby
71.Kittlitz's Murrelet
72.Titicaca Grebe
73.Greater Adjutant
74.Western Bristlebird
75.Eastern Bristlebird
76.Shore Plover
77.Udzungwa Forest-partridge
78.Madagascar Fish-eagle
79.White-bellied Heron
80.Subdesert Mesite
81.Long-whiskered Owlet
82.Philippine Cockatoo
83.Spix's Macaw
84.South Island Wren
85.Crow Honeyeater
86.Northern Brown Kiwi
87.Banded Ground-cuckoo
88.Flores Hawk-eagle
89.Tachira Antpitta
90.Beck's Petrel
91.Cebu Flowerpecker
92.Blue-eyed Ground-dove
93.Javan Trogon
94.Pulitzer's Longbill
95.Alagoas Antwren
96.Pernambuco Pygmy-owl
97.Jamaica Petrel
98.Grenada Dove
99.Wood Snipe
100.Rio de Janeiro Antwren