słonie: Theropoda

Evidence: 89 • authority: 72

Birds are vertebrate animals constituting the class Aves, characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton. They are warm-blooded, live worldwide, and range in size from the 5.5 cm (2.2 in) bee hummingbird to the 2.8 m (9 ft 2 in) common ostrich. There are over 11,000 living species of birds, classified in 44 orders. More than half of the world's bird species are passerine or "perching" birds. Nearly all birds have wings whose development varies according to the life style of each species. Wings, which are modified forelimbs, gave birds the ability to fly, although further…

Evidence: 66 • authority: 72

The following is a glossary of common English language terms used in the description of birds—warm-blooded vertebrates of the class Aves and the only living dinosaurs. Birds, who have feathers and the ability to fly (except for the approximately 60 extant species of flightless birds), are toothless, have beaked jaws, lay hard-shelled eggs, and have a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton. Among other details such as size, proportions and shape, terms defining bird features developed and are used to describe features unique to the class—especially evolutionary adaptations that developed to aid flight. There are, for example, numerous terms describ…

Evidence: 45 • authority: 72

About 216 species of birds have become extinct since 1500, with increasing extinction rates due to human-caused influences such as habitat loss, the introduction of invasive species, and climate change. Currently there are approximately 10,000 living species of birds, with over 1,480 at risk of extinction and 223 critically endangered. Island species in general, and flightless island species in particular, are most at risk. The situation is exemplified by Hawaii, where 30% of all known recently extinct bird taxa originally lived, and Guam, which lost over 60% of its native bird taxa in the decades following the introduction of the brown tree snake (Boiga irregularis). The disproportionate n…

Evidence: 45 • authority: 72

Elephant birds are extinct flightless birds belonging to the order Aepyornithiformes that were native to the island of Madagascar. They are thought to have gone extinct around 1000 AD, likely as a result of human activity. There are three currently recognised species, one in the genus Mullerornis, and two in Aepyornis. Aepyornis maximus is possibly the largest bird to have ever lived, with their eggs being the largest known for any amniote. Elephant birds were herbivores and major components of Madagascar's pre-human ecosystems. Elephant birds are palaeognaths (whose flightless representatives are often known as ratites), and their closest living relatives are kiwi (found only in New Zealan…

Evidence: 24 • authority: 80

'Tree of life' constructed for all living bird species

Evidence: 24 • authority: 80

All living bird species mapped in giant family tree

Evidence: 24 • authority: 92

Historic residential segregation impacts biodiversity data availability disparately across the tree of life.. Historical residential segregation policies have left a lasting impact on urban environments, greenspaces, and wildlife communities, creating socioeconomic heterogeneity and altering biota. However, the extent to which these policies continue to impact urban biodiversity remains unclear, especially across taxonomic groups and spatial scales. We explore how sampling and biodiversity metrics (sampling density, estimated completeness of sampling, and expected species richness) across taxonomic groups vary across historically redlined neighborhoods and relative to broader urban areas. T…

Evidence: 24 • authority: 72

The largest extant species of bird measured by mass is the common ostrich (Struthio camelus), closely followed by the Somali ostrich (Struthio molybdophanes). A male ostrich can reach a height of 2.8 metres (9.2 feet) and weigh up to 156.8 kg (346 lb), A mass of 200 kg (440 lb) has been cited for the ostrich but no wild ostriches of this weight have been verified. Ostrich eggs are the largest of any living bird, averaging 1.4 kg (3.1 lb). The largest wingspan of any extant bird is that of the wandering albatross (Diomedea exulans) of the Sub-Antarctic oceans. The largest dimensions found in this species are an approximate head-to-tail length of 1.44 m (4.7 ft) and a wingspan of 3.65 m (12.0…

Evidence: — • authority: 54