The Yukon Flats National Wildlife Refuge is a protected wetland area in the U.S. state of Alaska . It encompasses most of the Yukon Flats , a vast wetland area centered on the confluence of the Yukon River , Porcupine River , and Chandalar River .
17-722: The area is a major waterfowl breeding ground, and after a proposal to flood the Yukon Flats via a dam on the Yukon River was turned down, the Yukon Flats were deemed worthy of protection. On 1 December 1978, US President Jimmy Carter designated the Yukon Flats as a National Monument on the basis of the Antiquities Act of 1906. In the course of the Alaska National Interest Lands Conservation Act of December 2, 1980,
34-597: A consequence of sexual conflict between males and females, resulting in coevolutionary process that reduce fit, or that functions to decrease ease of having sex. The Anseriformes and the Galliformes ( pheasants , etc.) belong to a common group, the Galloanserae . They are the most primitive neognathous birds, and as such they should follow the palaeognathae ( ratites and tinamous ) in bird classification systems. Several unusual extinct families of birds like
51-409: A considerable number of mainly Late Cretaceous and Paleogene fossils have been described where it is uncertain whether or not they are anseriforms. This is because almost all orders of aquatic birds living today either originated or underwent a major radiation during that time, making it hard to decide whether some waterbird-like bone belongs into this family or is the product of parallel evolution in
68-1158: A different lineage due to adaptive pressures. Living Anseriformes based on the work by John Boyd. Anhima [REDACTED] Chauna [REDACTED] Anseranas [REDACTED] Dendrocygna [REDACTED] Thalassornis [REDACTED] Plectropterus [REDACTED] Stictonetta Nettapus [REDACTED] Biziura [REDACTED] Heteronetta [REDACTED] Nomonyx Oxyura [REDACTED] Malacorhynchus [REDACTED] Coscoroba Cereopsis [REDACTED] Sthenelides [REDACTED] Cygnus [REDACTED] Branta [REDACTED] Anser [REDACTED] Merganetta [REDACTED] Chloephaga [REDACTED] Oressochen Neochen [REDACTED] Radjah [REDACTED] Tadorna [REDACTED] Alopochen [REDACTED] Histrionicus † Camptorhynchus [REDACTED] Clangula [REDACTED] Polysticta [REDACTED] Somateria [REDACTED] Melanitta [REDACTED] Bucephala [REDACTED] Mergellus [REDACTED] Presbyornithid Presbyornithidae
85-532: A flat duck-like bill adapted for filter feeding . At least some species were social birds that lived in large flocks and nested in colonies, while others like Wilaru were terrestrial and territorial. Specimens of presbyornithids have also been discovered from the Lance Formation of Wyoming . Other possible Eocene presbyornithids include Presbyornis mongoliensis from Mongolia , Proherodius oweni and Headonornis hantoniensis from England with
102-519: A location in the Yukon-Koyukuk Census Area, Alaska is a stub . You can help Misplaced Pages by expanding it . Waterfowl Anseriformes is an order of birds also known as waterfowl that comprises about 180 living species of birds in three families: Anhimidae (three species of screamers), Anseranatidae (the magpie goose), and Anatidae , the largest family, which includes over 170 species of waterfowl, among them
119-413: A mix of characters shown by waterbirds, shorebirds and flamingos and were used to argue for an evolutionary relationship between these groups, but they are now generally accepted to be waterfowl closely related to modern ducks, geese, and screamers . They were generally long-legged, long-necked birds, standing around one meter high, with the body of a duck, feet similar to a wader but webbed , and
136-806: Is an extinct group of birds found in North America , South America , East Asia , Australia and possibly North Africa . They had evolved by the Maastrichtian age of the Late Cretaceous and became extinct during the Aquitanian age of the Early Miocene . The family contains the oldest known neognath , Teviornis from the Nemegt Formation of Mongolia . Initially, presbyornithids were believed to present
153-576: Is home to bird and mammalian species such as the Arctic fox , moose , bald eagle , black bear , wolf packs, porcupine , four species of falcon , river otter , golden eagle , red fox , Dall sheep , muskrat , coyote , six species of owl , Canadian lynx , beaver , caribou , mink , wolverine , and brown bear . This article related to a protected area in Alaska is a stub . You can help Misplaced Pages by expanding it . This article about
170-512: The ducks , geese , and swans . Most modern species in the order are highly adapted for an aquatic existence at the water surface. With the exception of screamers, males have penises , a trait that has been lost in the Neoaves . Due to their aquatic nature, most species are web-footed. Anseriformes are one of only two types of modern bird to be confirmed present during the Mesozoic alongside
187-404: The albatross-like pseudotooth birds and the giant flightless gastornithids and mihirungs have been found to be stem-anseriforms based on common features found in the skull region, beak physiology and pelvic region. The genus Vegavis for a while was found to be the earliest member of the anseriform crown group but a recent 2017 paper has found it to be just outside the crown group in
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#1732772835356204-715: The area boundaries were changed after political criticism and the status was downgraded to that of a wildlife refuge. It is the third-largest National Wildlife Refuge in the United States, although it is less than one-half the size of either of the two largest, the Arctic National Wildlife Refuge , or the Yukon Delta National Wildlife Refuge . The refuge is administered from offices in Fairbanks . This refuge
221-499: The common ancestors of ducks, geese, swans, and screamers , the last group once thought to be galliformes, but now genetically confirmed to be closely related to geese. The first known duck fossils start to appear about 34 million years ago. Waterfowl are the best-known examples of sexually antagonistic genital coevolution in vertebrates, causing genital adaptations to coevolve in each sex to advance control over mating and fertilization. Sexually antagonistic coevolution (or SAC) occurs as
238-533: The dabbling ducks or shelducks, is not fully resolved. See the Anatidae article for more information, and for alternate taxonomic approaches. Anatidae is traditionally divided into subfamilies Anatinae and Anserinae. The Anatinae consists of tribes Anatini , Aythyini , Mergini and Tadornini . The higher-order classification below follows a phylogenetic analysis performed by Mikko's Phylogeny Archive and John Boyd's website. Unassigned Anatidae: In addition,
255-457: The family Vegaviidae . Below is the general consensus of the phylogeny of anseriforms and their stem relatives. † Pelagornithidae (pseudo-tooth birds) [REDACTED] † Gastornithidae [REDACTED] † Dromornithidae (mihirungs) [REDACTED] † Vegaviidae Anseriformes (screamers and waterfowl) [REDACTED] [REDACTED] [REDACTED] Anatidae systematics, especially regarding placement of some "odd" genera in
272-483: The open, a condition that took centuries to recover from. The anseriformes and galliformes are thought to have survived in the cover of burrows and water, and not to have needed trees for food and reproduction. The earliest known stem anseriform is the presbyornithid Teviornis from the Nemegt Formation of Mongolia . Some members apparently surviving the KT extinction event , including presbyornithids , thought to be
289-468: The other dinosaurs, and in fact were among the very few birds to survive their extinction, along with their cousins the galliformes . These two groups only occupied two ecological niches during the Mesozoic, living in water and on the ground, while the toothed enantiornithes were the dominant birds that ruled the trees and air. The asteroid that ended the Mesozoic destroyed all trees as well as animals in
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