";s:4:"text";s:4274:" Logue DM(1), Hall ML. For more than a century, the small theropod dinosaur Archaeopteryx lithographica from the Late Jurassic period was considered to have been the earliest bird. Most birds cannot move their eyes, although there are exceptions, such as the great cormorant. Author information: (1)Departamento de Biología, Universidad de Puerto Rico, , PO Box 9000, Mayagüez PR 00681-9000, Puerto Rico, Department of Zoology, University of Melbourne, , … Birds are categorized as a biological class, Aves.
Birds with eyes on the sides of their heads have a wide visual field, useful for detecting predators, while those with eyes on the front of their heads, such as owls, have binocular vision and can estimate distances when hunting. Birdsong is an intricate communications system: each tweet, chirp, click and trill confers a message. A passerine is any bird of the order Passeriformes, which includes more than half of all bird species. Songbirds are the best known group of vocal learners. Logue DM(1), Hall ML. The evolution of birds began in the Jurassic Period, with the earliest birds derived from a clade of theropod dinosaurs named Paraves. It has emerged as a model case for using a combination of data from fossils, living species, genealogies, and numerical analyses to study how entirely new body plans and behaviors originate, and how prominent living groups achieved their diversity over hundreds of millions of years of evolution 2, 3. In songbirds, evolution moves in fits and starts, a new study suggests. They could travel futher and wider in search of food, and live where no other creature could go. The origin of birds is now one of the best understood major transitions in the history of life. Recent palaeontological data and novel physiological hypotheses now allow a timescaled reconstruction of the evolution of endothermy in birds … The power of flight gave birds the edge over most other creatures. “The genetic evidence is clear about songbirds having come out of Australia, but not at all clear about when it first happened,” said Tim, who was not involved in the study. How birds became birds. But as Michael Webster, Director of the Macaulay Library at the Cornell Lab of Ornithology, tells host Steve Curwood, many factors, such as the environment, migration, climate change and pollution are influencing the evolution of birdsong in interesting and unique ways. Sometimes known as perching birds or songbirds , passerines are distinguished from other orders of birds by the arrangement of their toes (three pointing forward and one back), which facilitates perching, amongst other features specific to their evolutionary history in Australaves . The only exception here is social polyandry, where females are socially paired with more than one male and hence copulate with more than one male as … The findings provide new insights into songbirds evolution, however not everyone is likely to be convinced, commented Tim Low, biologist, AG columnist and author of Where Song Began.
Evolution of female promiscuity in Passerides songbirds Jan T. Lifjeld1*, Jostein Gohli1, Tomáš Albrecht2,3, Eduardo Garcia-del-Rey4, Lars Erik Johannessen1, Oddmund Kleven5, Petter Z. Marki1,6, Taiwo C. Omotoriogun1,7,8, Melissah Rowe1,9 and Arild Johnsen1 Abstract Background: Female promiscuity is highly variable among birds, and particularly among songbirds. By using recent techniques of molecular biology in combination with electrophysiological, anatomical, and behavioral studies we have gained new insights into the organization of brain structures used in vocal learning. Migration and the evolution of duetting in songbirds. Author information: (1)Departamento de Biología, Universidad de Puerto Rico, , PO Box 9000, Mayagüez PR 00681-9000, Puerto Rico, Department of Zoology, University of … Thus, there seems to be no strong association between social mating systems and female promiscuity in Passerides songbirds.