This is a list of Pelecaniformes species by global population. While numbers are estimates, they have been made by the experts in their fields. For more information on how these estimates were ascertained, see Wikipedia's articles on population biology and population ecology.
The IOC World Bird List (version 15.1) recognizes 118 species of Pelecaniformes, seven of which are extinct. As of December 2025, IUCN/BirdLife International have assessed 111 of these species (excepting dimorphic egret, splits from striated heron, the split of cattle egret, and the extinct Ascension night heron). This list follows IUCN classifications for species names and taxonomy. Where IUCN classifications differ from other ornithological authorities, alternative names/taxonomic statuses are noted.
Several species listed as members of Pelecaniformes are extinct:
Réunion ibis (Threskiornis solitarius) - last seen in 1763.
New Zealand bittern (Botaurus novaezealandiae) - last seen in 1890. IUCN/BirdLife International place this bird in genus Ixobrychus.
Bermuda night heron (Nyctanassa carcinocatactes) - last seen in 1610. Likely extinct shortly afterward.
Ascension night heron (Nycticorax olsoni) - likely went extinct circa 1500. Not listed by IUCN/BirdLife International.
Réunion night heron (Nycticorax duboisi) - likely went extinct in early 1700s.
Mauritius night heron (Nycticorax mauritianus) - likely went extinct in early 1700s.
Rodrigues night heron (Nycticorax megacephalus) - likely extinct circa 1761.
Species by global population Common nameBinomial namePopulationStatusTrendNotesImageWhite-bellied heronArdea insignis50-249Total population is estimated to be 70-400 individuals.Dwarf ibis (São Tomé ibis)Bostrychia bocagei130-1,700Estimate calculated from density and area estimates. Total population estimated to be 190-2,500 individuals.Giant ibisThaumatibis gigantea194Minimum estimate. Total population estimated to be 290 individuals.Northern bald ibisGeronticus eremita200-249Estimate for mature individuals only. Species is considered regionally extinct in Europe.Asian crested ibis (Crested ibis)Nipponia nippon330Total population estimated to be 550 individuals.White-shouldered ibisPseudibis davisoni670Minimum estimate. Estimate for total population is 1,000 individuals.Malagasy pond heronArdeola idae1,000-2,499Estimate is for mature individuals only.Australasian bitternBotaurus poiciloptilus1,000-2,499Madagascar heron (Humblot's heron)Ardea humbloti1,290-1,500Estimate is for mature individuals only.Malayan night heronGorsachius melanolophus1,300-13,000?Population on most recent IUCN assessment (2025) Is unknown. Values retained from 2016 assessment.Forest bitternZonerodius heliosylus1,500-7,000Total population is estimated to be 2,500-9,999 individuals.White-eared night heronOroanassa magnifica1,500-15,000Malagasy sacred ibisThreskiornis bernieri1,733-2,166Total population is estimated to be 2,600-3,250 individuals.Slaty egretEgretta vinaceigula2,500-3,000Total population is estimated to be 3,000-5,000 individuals.Madagascar crested ibis (Madagascar ibis)Lophotibis cristata2,500-9,999Total population is estimated to be <10,000 individuals.Andean ibisTheristicus branickii2,500-9,999Total population is estimate to be 4,250-13,400 individuals.Schrenck's bittern (Von Schrenk's bittern)Botaurus eurhythmus2,500-25,000Total population estimated to be 1,000-50,000 individuals. IUCN/BirdLife International still place this bird in genus Ixobrychus.Black-faced spoonbillPlatalea minor3,000-5,100Total population estimated to be 6,500-7,500 individuals. Shoebill Balaeniceps rex 3,300-5,300 Total population estimated to be 5,000-8,000 individuals. Chinese egretEgretta eulophotes4,000-6,000Estimate is for mature individuals only.Japanese night heronGorsachius goisagi5,000-9,999Total population is estimated to be 7,500-15,000 individuals.Reddish egretEgretta rufescens5,000-9,999Estimate for mature individuals only.Puna ibisPlegadis ridgwayi5,000-20,000Population estimate is highly uncertain.Yellow-billed spoonbillPlatalea flavipes6,600-16,600Total population is estimated to be 10,000-25,000 individuals.White-necked heronArdea pacifica6,700-16,700Total population is estimated to be 10,000-25,000 individuals.White-faced heronEgretta novaehollandiae6,700-66,700?Total population is estimated to be 9,999-99,999 individuals.Rufous-bellied heronArdeola rufiventris6,700-66,700Total population is estimated to be 10,000-100,000 individuals.Goliath heronArdea goliath6,700-66,700Total population is estimated to be 10,070-100,070 individuals.Southern bald ibisGeronticus calvus7,000-8,000Estimate is for mature individuals only. Spot-billed pelican Pelecanus philippensis 8,700-12,000 Total population is estimated to be 13,000-18,000 individuals. Australian little bittern (Black-backed bittern)Botaurus dubius<10,000Value given is a tentative guess for number of mature individuals. IUCN/BirdLife International still places species in Ixobrychus.Agami heronAgamia agami10,000-25,000Values given are a shaky estimate of number of mature individuals.Wattled ibisBostrychia carunculata10,000-25,000?Sharp-tailed ibisCercibis oxycerca10,000-25,000?Values given are for total population. This estimate is now considered outdated. Dalmatian pelican Pelecanus crispus 11,400-13,400 Estimate is for mature individuals only. Great-billed heronArdea sumatrana11,700-71,700Total population is estimated to be 17,500-107,500 individuals.Olive ibisBostrychia olivacea15,000-45,000Total population is estimated to be <45,000 individuals.Pied heronEgretta picata16,700-66,700?Total population is estimated to be 25,000-100,000 individuals.Black-faced ibisTheristicus melanopis16,700-66,700Total population is estimated to be 25,000-100,000 individuals.Dwarf bitternBotaurus sturmii16,700-66,700?Total population is estimated to be 25,000-100,000 individuals. IUCN/BirdLife International still place this bird in genus Ixobrychus.Black heronEgretta ardesiaca16,700-66,700Total population is estimated to be 25,000-100,000 individuals.Yellow-billed egretArdea brachyrhyncha16,700-66,700Total population is estimated to be 25,000-100,000 individuals.Chinese pond heronArdeola bacchus16,700-667,000Total population is estimated to be 25,000-1,000,000 individuals.Rufescent tiger-heronTigrisoma lineatum18,000-70,000Total population is estimated to be 27,700-105,500 individuals. Note: the banner population and population description sections of the cited IUCN assessment disagree. Provided values were chosen to be reported based on agreement between mature and total individual estimates.Fasciated tiger-heronTigrisoma fasciatum20,000-49,999Tentative estimate, which is higher than the Wetlands International estimate for total population (c.14,500-17,000 individuals).African spoonbillPlatalea alba20,700-46,700Total population is estimated to be 31,000-70,000 individuals.Whistling heronSyrigma sibilatrix23,300-73,300Total population is estimated to be 35,000-110,000 individuals.Nankeen night heronNycticorax caledonicus24,700-743,000Total population is estimated to be 37,000-1,113,999 individuals.White-backed night heronCalherodius leuconotus25,000-100,000Values given are for total population.White-crested tiger-heronTigriornis leucolopha25,000-100,000Values given are for total population.Royal spoonbillPlatalea regia25,000-100,000Values given are for total population. May be an underestimate.Black bitternBotaurus flavicollis30,000-214,000?Total population is estimated to be 45,002-320,499 individuals. IUCN/BirdLife International still place this bird in genus Ixobrychus.Pink-backed pelicanPelecanus rufescens33,300-66,700Total population is estimated to be 50,000-100,000 individuals.Plumbeous ibisTheristicus caerulescens33,300-66,700Total population is estimated to be 50,000-100,000 individuals.Buff-necked ibisTheristicus caudatus33,300-133,000Total population is estimate to be 50,000-200,000 individuals.Western reef-egret (Western reef heron)Egretta gularis36,000-92,700Total population is estimated to be 54,000-139,000 individuals. Note that IOC taxonomy splits one additional species, the dimorphic egret, from this species.
IUCN/BirdLife International maintain both species under E. gularis.Australian pelicanPelecanus conspicillatus46,700-200,000Total population is estimated to be 70,000-300,000 individuals.Hadada ibisBostrychia hagedash46,700-267,000?Total population is estimated to be 70,000-400,000 individuals.Capped heronPilherodius pileatus50,000-499,999Values given are for total population.Bare-throated tiger-heronTigrisoma mexicanum50,000-499,999Estimate is for mature individuals only.Pinnated bitternBotaurus pinnatus50,000-499,999Estimate is for mature individuals only.Green ibisMesembrinibis cayennensis50,000-499,999Estimate is for mature individuals only.Eurasian spoonbillPlatelea leucorodia52,800-63,900Total population is estimated to be 79,250-95,850 individuals.Scarlet ibisEudocimus ruber66,700-100,000Total population is estimated to be 100,000-150,000 individuals.Black-headed heronArdea melanocephala66,700-333,000Total population is estimated to be 100,000-500,000 individuals.Indian pond heronArdeola grayii66,700-667,000?Total population is estimated to be 99,998-999,998 individuals.Plumed egretArdea plumifera66,700-667,000?Total population is estimated to be 100,000-1,000,000 individuals.Yellow bitternBotaurus sinensis66,700-667,000?Total population is estimated to be 100,000-1,000,299 individuals. IUCN/BirdLife International still place this bird in genus Ixobrychus. Roseate spoonbillPlatalea ajaja68,500-171,000Total population is estimated to be 102,800-256,800 individuals.Stripe-backed bitternBotaurus involucris73,300-683,000Total population is estimated to be 110,000-1,025,000 individuals. IUCN/BirdLife International still place this bird in genus Ixobrychus. Bare-faced ibisPhimosus infuscatus83,300-733,000Total population is estimated to be 124,999-1,099,999 individuals.Cinnamon bitternBotaurus cinnamomeus83,300-1,330,000?Total population is estimated to be 125,000-2,000,000 individuals. IUCN/BirdLife International still place this bird in genus Ixobrychus.Least bitternBotaurus exilis93,300-106,000Total population is estimated to be 139,999-158,999 individuals. IUCN/BirdLife International still place this bird in genus Ixobrychus. American white pelican Pelecanus erythrorhynchos 100,000-499,999 Best estimate for number of mature individuals is 450,000. Straw-necked ibisThreskiornis spinicollis100,000-1,000,000Values given are for total population. Peruvian pelican Pelecanus thagus 100,000-1,000,000 Values given are for total population. Pacific reef-egret (Pacific reef heron)Egretta sacra100,000-1,000,000Values given are for total population.HamerkopScopus umbretta113,000-743,000?Total population is estimated to be 170,000-1,115,000 individuals.Glossy ibisPlegadis falcinellus119,000-860,000Total population is estimated to be 178,500-1,289,499 individuals.Green-backed heron (Striated heron)Butorides striata173,000-1,500,000Total population is estimated to be 260,000-2,300,000 individuals. Note that IOC taxonomy splits three additional species, green heron, little heron, and lava heron, from this species.
IUCN/BirdLife International maintain all four species under B. striata.Purple heronArdea purpurea180,000-380,000Total population is estimated to be 270,000-570,000 individuals.Eurasian bitternBotaurus stellaris184,000-310,000Total population is estimated to be 275,699-465,199 individuals.African sacred ibisThreskiornis aethiopicus200,000-450,000Estimate is for mature individuals only.Spot-breasted ibisBostrychia rara200,000-510,000Values given are for total population.Tricolored heronEgretta tricolor206,000-219,000Total population is estimated to be 308,350-328,699 individuals.White ibis