Birds

Snow goose

Snow goose (Anser caerulescens), Arctic-breeding North American goose with white and blue color morphs; about 16 million birds, overabundant and managed by special conservation hunts due to tundra habitat damage.

Snowy owl

Snowy owl (Bubo scandiacus, harfang des neiges), a large diurnal Arctic tundra owl, North America's heaviest at about 4 pounds, feeding mainly on lemmings; IUCN Vulnerable since 2017 and Threatened in Canada since 2025.

Somateria mollissima

Somateria mollissima, the common eider (Eider à duvet), is a large circumpolar sea duck of Anatidae, the Northern Hemisphere's largest duck, nesting in down-lined colonies and listed IUCN Near Threatened.

Song thrush

Song thrush (Turdus philomelos), a Eurasian woodland and garden songbird known for repeating song phrases and smashing snails on anvils; UK population down 45% since 1967 but recovering recently.

Songbird

Songbird (oscine, suborder Passeri of Passeriformes): perching birds with a complex bipartite syrinx that learn their songs, like humans and unlike most animals. Nearly half of all bird species; originated in Australia; key model for vocal learning neuroscience.

Southern cassowary

Southern cassowary (Casuarius casuarius, double-wattled cassowary), a large flightless ratite of New Guinea and north Queensland rainforests; up to 2 m and 76 kg, fruit-eating keystone seed disperser, IUCN Vulnerable, EPBC Endangered in Australia.

Sparrow

Sparrow: small seed-eating passerines, chiefly the house sparrow (Passer domesticus), the world's most abundant bird at 1.6 billion, human-associated, IUCN Least Concern but declining in North America and Europe.

Spheniscus

Spheniscus, the banded penguins, is a genus of four allopatric species (African, Humboldt, Magellanic, Galapagos) breeding on cold currents; the only fossil penguins inside the crown clade Spheniscidae belong to it.

Spheniscus humboldti

Spheniscus humboldti, the Humboldt or Peruvian penguin (pingüino de Humboldt), is a Vulnerable banded penguin of the Humboldt Current off Peru and Chile, eating anchovies and sardines, nesting in guano burrows, and suffering sharp El Niño-driven declines.

Sphyrapicus

Sphyrapicus, the sapsuckers, is a genus of four North American woodpeckers erected by Baird in 1858: varius, nuchalis, ruber, thyroideus. They drill sap wells in live trees and feed on sap with brush-tipped tongues.

Spinus

Spinus is a genus of finch family birds holding the American siskins and goldfinches plus the Eurasian siskin and Tibetan serin, comprising 20 species, many moved from Carduelis.

Spix's macaw

Spix's macaw (Cyanopsitta spixii, ararinha-azul), a small blue macaw endemic to Brazil's Caatinga, declared Extinct in the Wild in 2019 after the last wild male vanished in 2000; about 360 survive in captivity, with reintroductions since 2022.

Spiza

Spiza (Bonaparte, 1824) is a monotypic cardinalid genus containing only the Dickcissel, Spiza americana, a North American grassland songbird with a namesake song, erratic movements, and winter roosts in Venezuela.

Spizaetus

Spizaetus (Vieillot, 1816) is a genus of four Neotropical forest eagle species, ornatus, tyrannus, melanoleucus, isidori; former Old World hawk-eagles were moved to Nisaetus after molecular phylogenies showed paraphyly.

Sporophila

Sporophila, the seedeaters, a Thraupidae genus of small Neotropical granivorous birds (about 38 species) with thick bills and dimorphic plumage; includes the rapidly radiated capuchinos and absorbed Oryzoborus and Dolospingus.

Spot-bellied eagle-owl

Spot-bellied eagle-owl (Bubo nipalensis, Ketupa nipalensis), also called forest eagle-owl: a large 51–63 cm Asian forest owl from the Himalayas to Southeast Asia, taking jackals to peafowl, one-egg clutches, IUCN Least Concern but Endangered in Nepal.

Squab

Squab: a young domestic pigeon under four weeks old, or its tender dark meat, from the rock pigeon Columba livia; China produces about 680 million squabs yearly, over 80% of global output.

Starling

Starling (Sturnus vulgaris), the common or European starling, a Sturnidae songbird famed for murmurations and mimicry; invasive in North America (200 million birds from an 1890 release) yet red-listed and declining in its native UK range.

Steatornis

Steatornis is a monotypic genus of nocturnal, cave-roosting Neotropical birds whose single species is the oilbird, known locally as the guácharo, one of the few birds that echolocates.

Steller's jay

Steller's jay (Cyanocitta stelleri), Chara de Steller, Geai de Steller: a large black-crested, blue-bodied corvid of western North American conifer forests from Alaska to Nicaragua, named for naturalist Georg Steller; IUCN Least Concern, about 3 million birds.

Steller's sea eagle

Steller's sea eagle, Haliaeetus pelagicus, is a large fish eagle of the Russian Far East and one of the world's heaviest eagles, wintering mainly on Hokkaido, Japan.

Stenonychosaurus

Stenonychosaurus, a small 2.5 m troodontid theropod dinosaur from the Late Cretaceous (77–74 Ma) of Canada, named by Sternberg in 1932; long synonymized with Troodon, its validity is disputed, with large-toothed omnivory and a large brain.

Steppe eagle

Steppe eagle (Aquila nipalensis), a large Endangered migratory raptor of Eurasian steppe breeding in Kazakhstan, Mongolia, and Russia, wintering in Africa, Arabia, and South Asia; threatened by electrocution, poisoning, and habitat loss.

Stercorarius

Stercorarius is a genus of predatory seabirds known as skuas and jaegers, the sole genus of the family Stercorariidae, established by Brisson in 1760 with the Parasitic Jaeger as its type species.

Sternula

Sternula (Boie, 1822) is a genus of small terns in Laridae, type species the Little Tern S. albifrons; seven species including the Least Tern, Fairy Tern, and Peruvian Tern, separated from Sterna on molecular grounds.

Stork

A stork is a large wading bird of the family Ciconiidae, a group of 20 species found across tropical and subtropical regions, known for soaring migration on thermals.

Streptopelia

Streptopelia (turtle-doves) is a genus of Columbidae doves of Europe, Asia, and Africa, with 15 recognized species, weak molecular monophyly, a critically declining turtle dove, and the invasive Eurasian collared-dove.

Streptopelia senegalensis

Streptopelia senegalensis, the laughing dove (also Spilopelia senegalensis, palm dove), a small Columbidae dove of Africa, Arabia, and South Asia; IUCN Least Concern, expanding range, two-egg clutches, CITES Appendix III Ghana.

Strigidae

Strigidae, the typical or true owls, is the larger of the two owl families (with Tytonidae), with roughly 190-234 species in 23-28 genera, circular facial disks, worldwide range except Antarctica, mostly tropical forest-dwelling non-migratory hunters.