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Encyclopedia > Laysan Duck
Laysan Duck
Male specimen in Cologne Zoo
Male specimen in Cologne Zoo
Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Anseriformes
Family: Anatidae
Genus: Anas
Species: A. laysanensis
Binomial name
Anas laysanensis
Rothschild, 1892

The Laysan Duck (Anas laysanensis), also known as the Laysan Teal because of its small size, is an endangered dabbling duck endemic to the Hawaiian Archipelago. Fossil evidence reveals that Laysan Ducks once lived across the entire Hawaiian Island chain, but today survive only on three small, isolated islands. Image File history File links Size of this preview: 800 × 597 pixelsFull resolution (1017 × 759 pixel, file size: 267 KB, MIME type: image/jpeg) Male Laysan Duck/Laysan Teal (Anas laysanensis). ... Baboons in the open-air rock landscape. ... The conservation status of a species is an indicator of the likelihood of that species continuing to survive either in the present day or the future. ... Image File history File links Status_iucn3. ... . ... Scientific classification or biological classification is a method by which biologists group and categorize species of organisms. ... Phyla Subkingdom Parazoa Porifera (sponges) Subkingdom Agnotozoa Placozoa Orthonectida Rhombozoa Subkingdom Metazoa Radiata Cnidaria Ctenophora - Comb jellies Bilateria Protostomia Acoelomorpha Platyhelminthes - Flatworms Nemertina - Ribbon worms Gastrotricha Gnathostomulida - Jawed worms Micrognathozoa Rotifera - Rotifers Acanthocephala Priapulida Kinorhyncha Loricifera Entoprocta Nematoda - Roundworms Nematomorpha - Horsehair worms Cycliophora Mollusca - Mollusks Sipuncula - Peanut worms Annelida - Segmented... Typical Classes Subphylum Urochordata - Tunicates Ascidiacea Thaliacea Larvacea Subphylum Cephalochordata - Lancelets Subphylum Myxini - Hagfishes Subphylum Vertebrata - Vertebrates Petromyzontida - Lampreys Placodermi (extinct) Chondrichthyes - Cartilaginous fishes Acanthodii (extinct) Actinopterygii - Ray-finned fishes Actinistia - Coelacanths Dipnoi - Lungfishes Amphibia - Amphibians Reptilia - Reptiles Aves - Birds Mammalia - Mammals Chordates (phylum Chordata) include the vertebrates, together with... “Aves” redirects here. ... Families Anhimidae Anseranatidae Anatidae †Dromornithidae †Presbyornithidae The order Anseriformes contains about 150 species of birds in three families: the Anhimidae (the screamers), Anseranatidae (the Magpie-goose), and the Anatidae, which includes over 140 species of waterfowl, among them the ducks, geese, and swans. ... Subfamilies Dendrocygninae Thalassorninae Anserinae Stictonettinae Plectropterinae Tadorninae Anatinae Aythyinae Merginae Oxyurinae and see text Anatidae is the biological family that includes the ducks and most duck-like waterfowl, such as geese and swan. ... Species Some 40-50; see text. ... This article does not cite any references or sources. ... Lionel Walter Rothschild, 2nd Baron Rothschild (February 8, 1868 - August 27, 1937) was a British banker and zoologist from the international Rothschild financial dynasty. ... 1892 (MDCCCXCII) was a leap year starting on Friday (see link for calendar). ... Genera Pteronetta Cairina Aix Nettapus Anas Callonetta Chenonetta Amazonetta See also Diving duck The dabbling ducks are a group of eight genera and about 55 species of ducks, including some of the most familiar Northern Hemisphere species. ... Map of the Hawaiian Islands, a chain of islands that stretches 2,400 km in a northwesterly direction from the southern tip of the Island of Hawai‘i. ...

Contents

Description

Male Laysan Duck. Photo by Jimmy Breeden.

The Laysan Duck are members of the mallard clade of dabbling ducks, and are a behaviorally and genetically unique species. Recent evidence suggests they evolved from an east Asian, southern hemispheric ancestor of mallards, not from stray migratory Mallards (Anas platyrhynchos) which has been reported in the past (Johnson and Sorenson 1999). The Laysan Duck is teal-sized and dark brown, with a prominent white eye-ring. The bill is short and spatulate, dark green with variable black blotching in males, and dull orange with variable black blotching in females. Some males show faint iridescence on the head or neck and have slightly upturned central tail feathers. The wing has an iridescent purplish-green patch (speculum feathers) in both sexes. Leucistism, or extensive white feathering, is common on the head and neck of older birds. The legs and feet are orange, usually brighter in the male. The annual pre-basic molt is complete, and the ducks loose all their flight feathers and become incapable of flight until new feathers grow in. Wild ducks have been known to live to the age of twelve, and captive birds have lived to the age of eighteen. Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... A clade is a term belonging to the discipline of cladistics. ... A mallard hen. ... In birds, moulting or molting is the routine shedding of old feathers. ...


Ecology

Laysan Ducks chasing brine flies
Laysan Ducks chasing brine flies

The Laysan Duck walks and runs well, with a pelvic girdle adapted to terrestrial foraging. Energetic foraging behavior includes a fly-snapping sprint through Neoscatella sexnotata brine fly swarms. With necks outstretched, and bills close to the ground, the ducks run along a mudflat and as clouds of flies rise up in front, snap them up by rapidly opening and closing their bills. The ducks also will dabble and filter feed along lake shallows, shore, and in upland vegetation for macroinvertebrates, algae, leaves, and seeds (Reynolds et al. 2006). During the day, and especially in the breeding season, they prefer to hide among the grass and shrub vegetation, helping them to avoid avian predators such as frigatebirds. They prefer to venture out in the open and feed on the lake from dusk til dawn, although there seems to be marked variation from year to year according to the availability of food items.(Reynolds 2004) Laysan Duck pub domain from NOAA File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Laysan Duck pub domain from NOAA File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... The term macroinvertebrates is traditionally used to refer to aquatic invertebrates including insects (e. ... A seaweed (Laurencia) up close: the branches are multicellular and only about 1 mm thick. ... Species Fregata magnificens Fregata aquila Fregata andrewsi Fregata minor Fregata ariel There are five Derek Jeter in the family Fregatidae, the frigatebirds. ...

Laysan Duck Brood. Photo by Jimmy Breeden.
Laysan Duck Brood. Photo by Jimmy Breeden.

Pair formation begins in fall, and nest building begins in spring. The female builds a well-concealed nest on the ground below dense vegetation, especially Eragrostis variabilis bunchgrass. The nest is a shallow bowl lined with dead grass and down feathers. Egg-laying typically occurs from April to August. Average clutch size on Laysan Island is approximately four eggs. The newly established population on Midway lays larger clutches. Ducklings are precocial and feed on their own day two after hatching, but are guarded, brooded, and led to foraging sites by the hen for approximately 40 to 60 days. Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ...


Status and conservation

Decline to near-extinction

The decline of the Laysan Duck began 1000-1600 years ago, with the colonization of the Hawaiian Islands by Polynesians and associated non-native mammalian predators (Reynolds et al. 2004). By 1860, the ducks disappeared from all but Laysan Island (the duck’s namesake), most likely due to predation by introduced rats. Like many isolated island species, the Laysan Duck evolved in an environment lacking mammalian predators, and is ill-suited in defense against non-native ground hunters, such as humans, rats, pigs, and mongoose. For example, Laysan Ducks are more likely to freeze their movement rather than flush or fly when startled— a strategy well suited for cryptic defense against Hawaii’s native flying predators, but ineffective against ground predators. Although the non-migratory Laysan Duck can fly, it does not disperse between islands (USFWS 2004). Polynesia (from Greek, poly = many and nesi = island) is a large grouping of over 1,000 islands in the central and southern Pacific Ocean. ... Laysan, located at N25° 42 14 W171° 44 04, is one of the northwestern Hawaiian Islands. ... Subfamiles Herpestinae A mongoose is a member of the family of small cat-like carnivores. ...


The Laysan Duck found refuge through most of the nineteenth century on rat-free Laysan Island, surviving within the smallest geographic range of any duck species worldwide (415 hectares, or less than four square miles). Laysan Island gained federal protection in 1909, with the establishment of the Hawaiian Islands National Wildlife Refuge. However, devastation of the island’s vegetation by introduced rabbits brought the duck to the brink of extinction in 1911, with an all-time low population of 7 to 11 birds. The Hawaiian Islands National Wildlife Refuge (HINWR) is a National Wildlife Refuge of the United States, comprised of the northwestern Hawaiian Islands, with the exception of Midway Atoll and Kure Atoll. ...


Recovery

After many rabbits starved and the remaining ones were eradicated by biologists in 1926, the ducks began to recover, increasing to a population of about 200 in 1960. Congress passed the Endangered Species Preservation Act in 1966, and in 1967 the Laysan Duck was declared an endangered species with federal protection. However, population bottlenecks occurred, such as the severe 1993 El Niño drought and food shortage, which reduced the number of ducks to about 100. Today, breeding and survival of the birds is closely tracked. Since 1998, a sample of birds have been fitted with unique leg bands or radio transmitters for monitoring reproductive success and survival, revealing that typically only 30% of ducklings on Laysan Island survive to fledge (USGS 2005). In 2004, the population grew to an estimated 576 ducks. Chart of ocean surface temperature anomaly [°C] during the last strong El Niño in December 1997 El Niño and La Niña (also written in English as El Nino and La Nina) are major temperature fluctuations in surface waters of the tropical Eastern Pacific Ocean. ...


In October of 2004 and 2005, 42 Laysan Ducks were translocated to Midway Atoll National Wildlife Refuge as a collaborative effort between the U.S. Geological Survey and U.S. Fish and Wildlife Service to restore a second population of ducks in the wild. The creation of a second population, since disaster is unlikely to strike both atolls simutaneously, reduces the risk of extinction by random catastrophes such as drought, hurricanes, tsunamis, disease outbreaks (like avian flu), and accidental introductions of non-native plants and animals (USFWS 2005). Midway Atoll (also known as Midway Island or Midway Islands) is a 6. ... The United States Geological Survey (USGS) is a scientific agency of the United States government. ... The USFWS logo The United States Fish and Wildlife Service is a unit of the United States Department of the Interior that is dedicated to managing and preserving wildlife. ... For the current concern about the transmission of an avian flu to humans see Transmission and infection of H5N1. ...


The second “insurance” population of Laysan Ducks on Midway has grown quickly, more than doubling in size within the first two years (USGS 2006c). As of January 2007, 100 ducks call Midway’s Sand and Eastern Island home. Researchers monitoring the Midway population have found that the ducks are breeding at an earlier age, and laying more eggs than birds on Laysan. This suggests that the abundant habitat and food available on Midway has stimulated greater reproductive effort in the ducks, which contributes optimism for the success of this re-introducted population. (USGS 2006a, 2006b).


Future outlook

The persistence of the Laysan Duck into the future is optimistic, though threats to the population remain. Threats include the introduction of non-native species, which may change vital rates, displace native species and adversely affect nesting and foraging opportunities. Devastation to vegetation could increase sedimentation of the lakes and seeps that serve as important foraging habitat. Human disturbance may impact nesting and brooding, and landing permits to the Laysan Island refuge are granted only for official or scientific purposes. Debris and contaminants washed ashore by ocean currents could pose a serious threat to the duck. Pesticide containers and oil spills have contaminated Laysan in the past. The island homes of the duck are especially vulnerable to a rise in sea level and extreme weather associated with global warming. Even a slight rise in sea level would destroy a large portion of the duck’s current habitat. The spread of parasites such as the nematode Echinuria uncinata could be extremely pathogenic, as well as the introduction of disease by migratory waterfowl along the Pacific Flyway (such as avian flu, avian malaria, cholera, botulism and duck plague). Environmental catastrophes such as drought, severe storms, and tsunamis may decimate populations. The increased frequency and severity of storms are an anticipated effect of global warming (USFWS 2004). Sweet clover (), introduced and naturalized to the U.S. from Eurasia as a forage and cover crop, supports insect biodiversity. ... Global mean surface temperatures 1850 to 2006 Mean surface temperature anomalies during the period 1995 to 2004 with respect to the average temperatures from 1940 to 1980 Global warming is the observed increase in the average temperature of the Earths atmosphere and oceans in recent decades and the projected... Classes Adenophorea    Subclass Enoplia    Subclass Chromadoria Secernentea    Subclass Rhabditia    Subclass Spiruria    Subclass Diplogasteria The nematodes or roundworms (Phylum Nematoda from Greek (nema): thread + -ode like) are one of the most common phyla of animals, with over 20,000 different described species (over 15,000 are parasitic). ... The Pacific Flyway is one of the four major migration route for waterfowl in the United States, Canada and Mexico. ... For the current concern about the transmission of an avian flu to humans see Transmission and infection of H5N1. ... Avian malaria or Plasmodium relictum is a protist that infects birds in tropical regions. ... Cholera (or Asiatic cholera or epidemic cholera) is a severe diarrheal disease caused by the bacterium Vibrio cholerae. ... Botulism (from the Latin word botulus) is a rare, but serious paralytic illness caused by a nerve toxin, botulin, that is produced by the bacterium Clostridium botulinum. ... Duck plague (also known as duck viral enteritis) is a worldwide disease caused by duck herpesvirus 1 (anatid herpesvirus 1) of the family Herpesviridae that causes high mortality in flocks of ducks. ...


A recovery plan for the Laysan Duck has been developed by the U.S. Fish and Wildlife Service (USFWS 2004). The goal of the recovery program is to conserve and recover the species to the extent that it may be down-listed from endangered to threatened in the near future, and ultimately, that the population be healthy enough to no longer require federal protection under the Endangered Species Act. The emphasis of the recovery plan is the distribution of additional viable populations in the Laysan Duck’s historical and prehistorical range. The creation of multiple populations will decrease the risk that catastrophic events will result in species extinction. The increase of population size will diminish the threats from demographic and environmental uncertainties. To achieve this goal, biologists plan to establish at least five populations on a combination of predator-free Northwestern Hawaiian Islands and predator-controlled sites on Main Hawaiian Islands. This plan includes wild translocation and the establishment of a successful captive or semi-captive breeding program using wild source eggs for reintroductions to the Main Hawaiian Islands. Additionally, the plan calls for achieving gene flow between the wild source populations through long-term inter-island translocations, and island-specific management for each population to reduce threats and improve quality of habitat. If basic criteria of the recovery plan are met, the Laysan Duck could be down-listed from endangered to threatened by 2019. Threatened species refers to animal and plant species under a serious, but perhaps not imminent, threat of extinction. ... This article or section is in need of attention from an expert on the subject. ... In population genetics, gene flow (also known as gene migration) is the transfer of alleles of genes from one population to another. ...


References

  • Johnson, Kevin P. & Sorenson, Michael D. (1999): Phylogeny and biogeography of dabbling ducks (genus Anas): a comparison of molecular and morphological evidence. Auk 116(3): 792–805. PDF fulltext
  • Moulton, D.W. & Marshall, A.P. (1996): Laysan Duck (Anas laysanensis). In: Poole, A. & Gill, F. (eds.): The Birds of North America: 242. Academy of Natural Sciences, Philadelphia, PA & American Ornithologists' Union, Washington, D.C. Online version, retrieved 2007-FEB-08. DOI:10.2173/bna.242 (requires subscription)
  • Reynolds, Michelle H. (2004): Habitat use and home range of the Laysan Teal on Laysan Island, Hawaii. Waterbirds 27(2): 183-192. DOI:10.1675/1524-4695(2004)027[0183:HUAHRO]2.0.CO;2 HTML abstract
  • Reynolds, Michelle H.; Slotterback, J.W. & Walters, J.R. (2006): Diet composition and terrestrial prey selection of the Laysan Teal on Laysan Island. Atoll Research Bulletin 543: 181-199. PDF fulltext
  • US Fish and Wildlife Service (USFWS) (2004): Draft Revised Recovery Plan for the Laysan Duck (Anas laysanensis). Portland, OR. PDF fulltext
  • US Fish and Wildlife Service (USFWS) (2005): New arrivals to Midway Atoll NWR provide “insurance” against extinction for nation’s rarest duck. News Release, Oct 28. PDF fulltext
  • US Geological Survey (USGS) (2005): Translocation of Endangered Laysan Ducks to Midway Atoll National Wildlife Refuge (2004-5). Fact sheet 2005-3128. PDF fulltext
  • US Geological Survey (USGS) (2006a): Second generation of the nation’s rarest ducks hatch after translocation. News Release, May 16.
  • US Geological Survey (USGS) (2006b): Midway Atoll national Wildlife Refuge welcomes second generation of nation’s rarest ducks. News release, May 23. PDF fulltext
  • US Geological Survey (USGS) (2006c): Endangered duck population reaches triple digits! News release, Oct 23. HTML fulltext

The Auk is a quarterly journal and the official publication of the American Ornithologists Union, having been continuously published by that body since 1884. ... The Academy of Natural Sciences in Philadelphia was founded in 1812 to expand knowledge of the natural world. ... The American Ornithologists Union (AOU) an ornithological organization in the USA. Unlike the National Audubon Society, its members are primarily professional ornithologists rather than amateur birders. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ...

External links


  Results from FactBites:
 
Laysan Duck - definition of Laysan Duck in Encyclopedia (240 words)
The Laysan Duck, Anas laysanensis, is a dabbling duck which is endemic to Laysan Island, Hawaii.
These ducks are related to the Mallard, and have sometimes been considered to be an island race of that species.
Laysan Island is only 3km long, and the population of this duck is based on the brackish central lagoon.
  More results at FactBites »

 
 

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