Hubbry Logo
AlopochenAlopochenMain
Open search
Alopochen
Community hub
Alopochen
logo
8 pages, 0 posts
0 subscribers
Be the first to start a discussion here.
Be the first to start a discussion here.
Alopochen
Alopochen
Alopochen
View on Wikipedia
from Wikipedia

Alopochen
Egyptian goose
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Anseriformes
Family: Anatidae
Subfamily: Tadorninae
Genus: Alopochen
Stejneger, 1885
Synonyms
  • Chenalopex Stephens 1824 non Vieillot 1818[1][2]
  • Mascarenochen Cowles 1994
  • Proanser Umans'ka 1979a
  • Anserobranta Kuročkin & Ganya 1972

Alopochen is a genus of the bird family Anatidae, part of the subfamily Tadorninae along with the shelducks. It contains one extant species, the Egyptian goose (Alopochen aegyptiaca), and three which became extinct in the last 1,000 years or so. The Egyptian goose is native to mainland Africa, and the recently extinct species are from Madagascar and the Mascarene Islands.

mtDNA cytochrome b sequence data suggest that the relationships of Alopochen to Tadorna need further investigation.[3]

Species

[edit]

The extinct species of the genus are:

The generic name looks like Greek ἀλώπηξ + χήν = "fox-goose", referring to the colour of its back, but with a Greek language error; the linguistically correct form would have been *Alopecchen or *Alopecochen.

References

[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Alopochen

View on Grokipedia
from Grokipedia
Alopochen is a monotypic of waterbirds in the shelduck subfamily Tadorninae within the family , comprising the single extant species Alopochen aegyptiaca, commonly known as the Egyptian goose. This species is a medium-sized , measuring 63–73 cm in length and weighing 1.5–2.3 kg, with distinctive plumage including a light brown body, dark brown eye patches, a contrasting white wing lining visible in flight, and pinkish legs and bill. Males are slightly larger than females, but the sexes are otherwise similar in appearance, though vocalizations differ with males producing hissing sounds and females cackling. Native to , particularly the Valley and southern regions, Alopochen aegyptiaca has been introduced to parts of (such as the , , , and ) since the and to (including ), where it has established feral populations. The species prefers open wetlands, rivers, lakes, marshes, and adjacent grasslands up to elevations of 4,000 m, avoiding dense forests, and is highly adaptable to human-modified landscapes. It is largely sedentary but may undertake local movements in response to or resource availability. Ecologically, the Egyptian goose is primarily herbivorous, foraging on grasses, seeds, crops, and aquatic vegetation, supplemented by small amounts of , and often feeds in flocks for protection. Breeding occurs year-round in equatorial regions but is seasonal elsewhere, with monogamous pairs nesting in tree cavities, on the ground, or in abandoned structures near water; clutches typically number 5–12 eggs. Although classified as Least Concern by the IUCN due to its large range exceeding 28 million km² and stable to increasing populations in parts of , it faces threats from as an agricultural pest and invasive status in introduced areas.

Taxonomy

Etymology

The genus Alopochen was introduced by Norwegian-American zoologist Leonhard Stejneger in 1885 as part of his contribution to the birds volume of The Standard Natural History. The name derives from alṓpēx (ἀλώπηξ, "fox") and khḗn (χήν, "goose"), reflecting the fox-like reddish-brown coloration of the back of the Egyptian goose (Alopochen aegyptiaca), the by subsequent designation in 1906. This compound alludes to the bird's plumage, which was noted in ancient descriptions for its ruddy hue. The form Alopochen represents a minor grammatical irregularity in Greek nomenclature; the linguistically precise rendering would be Alopecochen (using the genitive stem) or Alopecchen (with adjusted ), though the original spelling has been retained in taxonomic usage. The genus has several junior synonyms, including Chenalopex (Stephens, 1824, preoccupied and replaced), Mascarenochen (Cowles, 1994, for Mascarene taxa), Proanser (Umans'ka, 1979), and Anserobranta (Kuročkin & Ganya, 1972). (Note: The Cowles reference is to Geobios 27: 423–428.) Historically, the Egyptian goose was well-known to ancient civilizations; it frequently appears in Egyptian monumental and was recognized by the ancient under the name chenalopex ("fox-"), likely due to its back color.

Classification and phylogeny

Alopochen belongs to the kingdom Animalia, phylum Chordata, class Aves, order , family , and subfamily Tadorninae. The genus is placed within the Tadorninae subfamily, which includes shelducks and sheldgeese, on the basis of both morphological similarities—such as bill structure and plumage patterns—and molecular evidence from sequences. Phylogenetic analyses using and NADH dehydrogenase subunit 2 genes indicate that Alopochen forms a with shelducks, though the position requires additional genomic data for resolution due to limited sampling of basal divergences. Beyond this subfamily affiliation, Alopochen has no particularly close extant relatives, reflecting its isolated evolutionary position within the . Historically, the single extant species was classified in separate genera, such as by early taxonomists, before recognition of its distinct traits led to the establishment of Alopochen. The genus was later expanded to incorporate extinct island-endemic species based on sub evidence, including extinct island species from the . While monotypic among living species, Alopochen now encompasses a broader record that underscores its phylogenetic depth within Tadorninae.

Species

Extant species

The genus Alopochen includes a single extant , the Egyptian goose (Alopochen aegyptiaca (Linnaeus, 1766)), which is monotypic and lacks recognized subspecies. The is assessed as Least Concern by the IUCN.

Extinct species

The genus Alopochen includes three extinct species known primarily from subfossil remains and limited historical accounts, all endemic to islands in the western Indian Ocean. The Mauritius sheldgoose (Alopochen mauritiana) was endemic to Mauritius and last recorded in 1693, becoming extinct by around 1698. It is known from subfossil bones, including carpometacarpus and pelvic elements collected in the 19th century, as well as brief descriptions by 17th-century Dutch travelers such as Johannes Pretorius, who noted the bird in wooded areas and dry ponds. The (Alopochen kervazoi) was endemic to and last reliably reported in 1671–1672, with occurring by circa 1700. It is documented through subfossil bones discovered in 1974 at the Grottes des Premiers Français and historical observations by explorers like Nontekoe (1619) and Dubois (1671–1672). The Malagasy shelduck (Alopochen sirabensis) was endemic to and extinct by approximately 1000–1400 CE. It is represented by abundant subfossil bones from sites including (formerly Sirabe) and Ampasambazimba, with from Beloha placing remains around 1380 ± 90 years . These species share common traits as island endemics with no surviving specimens, having vanished between roughly 1000 and 300 years ago based on subfossil and historical evidence. Their placement in Alopochen derives from subfossil morphological analyses confirming close relation to the Egyptian goose.

Description

General morphology

Alopochen species exhibit a shelduck-like build characterized by a robust body adapted for both terrestrial and aquatic lifestyles. The extant , Alopochen aegyptiaca, measures 63–73 cm in length, with a wingspan of 134–154 cm and body mass ranging from 1.5 to 2.3 kg. These birds possess strong, relatively long legs positioned toward the rear of the body, facilitating efficient walking on land and occasional perching in trees or on structures. Their feet are webbed, aiding propulsion in water, and equipped with strong claws that enhance grip for perching. The wings are broad and powerful, supporting sustained flight despite the heavy body. The bill is broad and flattened, adapted for on and probing soft substrates. is limited primarily to size, with males larger and averaging about 25% heavier than females, though no significant structural differences in the bill or feet are noted between sexes.

Plumage variation

The adult plumage of the Egyptian goose (Alopochen aegyptiaca) is characterized by a pale grey-brown head and upper neck, with a conspicuous dark brown eye patch extending from the eyes to the . The chest is cinnamon-colored, transitioning to white underparts marked by variable dark brown patches on the breast and flanks, while the back displays a foxy-brown tone with fine vermiculations. The wings include prominent white secondary coverts with black bases, contrasting with glossy greenish-black secondaries and a variable amount of dark reddish-brown on the upperwing coverts; these white panels become highly visible during flight or territorial displays. There is no sexual dimorphism in plumage, though males tend to be slightly larger overall. tones can vary individually from greyer to browner, but this variation is not linked to age, , or , with little documented geographic variation across the ' range. Juveniles possess duller, more uniform grey-brown , featuring a crown and without the distinct dark eye patch, greyish wing coverts with blackish markings, and buffish underparts; they undergo a prejuvenile molt over approximately 60–70 days, attaining adult-like by 2–3 months of age. Egyptian geese experience an annual definitive prebasic molt that is incomplete to complete, primarily affecting the wings and rendering the birds flightless for a period of at least 29 days (typically 3–4 weeks), with the process spanning about 53 days and peaking in the austral summer in .

Distribution and habitat

Historical distribution

The genus Alopochen has a historical distribution centered in , with the sole extant species, Alopochen aegyptiaca, native to the Valley and much of . Its range originally spanned from western regions including and eastward to , , and , and southward through , , , and to , encompassing countries such as , , , , , , , , , , , , , , , , , , , , , , , , , , and . This species occurred from up to altitudes of 4,000 m, particularly in the . Three extinct species of Alopochen were historically restricted to isolated islands in the Indian Ocean. The fossil record of Alopochen originates in the Miocene, with the genus first appearing around 11 million years ago during the Tortonian stage in eastern Europe (Moldova), though subsequent records are primarily African. Modern Alopochen species are known from post-Pleistocene deposits, including Upper Pleistocene remains of A. aegyptiaca near the Sea of Galilee in the Levant. Pre-Holocene records include Miocene fossils from eastern Europe (Moldova) and are otherwise primarily from Africa. Historically, Alopochen species preferred open habitats such as grasslands, freshwater wetlands, marshes, lakes, reservoirs, rivers, and riverine corridors, often near meadows and arable lands with emergent vegetation. They avoided dense forests and arid true deserts, favoring areas with open shorelines and short-grass cover for foraging and nesting.

Current distribution

The Egyptian goose (Alopochen aegyptiaca), the sole extant species in the genus Alopochen, maintains a widespread native distribution across and the Nile River valley, with stable populations in core regions of East and . It is particularly abundant in countries such as , , , , and , where it inhabits wetlands, rivers, and grasslands. Although precise global population figures are not available due to data limitations, estimates for Southern and Eastern Africa alone suggest 200,000–500,000 individuals, indicating overall stability in native strongholds despite some regional declines. Introduced populations have established beyond the native range through ornamental releases and escapes from captivity. In , the species was first introduced to the in the late , forming a self-sustaining population that has since expanded; additional introductions occurred in the in 1967, leading to rapid growth across the , including , , , and . In , populations took hold in during the 1960s (with confirmed breeding by the 1980s), alongside smaller groups in and . Limited establishments exist in the Middle East, such as the and , while vagrant records appear in parts of like and , though no large-scale populations have formed there. Attempts to introduce the species to and failed to produce permanent breeding populations. In introduced regions, Egyptian geese commonly occupy human-modified habitats such as urban parks, courses, and agricultural fields adjacent to bodies, adapting well to suburban environments. Recent estimates indicate the European population exceeds 75,000 individuals, with over 100,000 in the alone as of 2023, and continues to expand rapidly, facilitated by mild climates and lack of severe winters. This species has been designated as invasive of Union concern by the since 2017, reflecting its accelerating range expansion and potential ecological impacts.

Ecology and behavior

Diet and foraging

Alopochen species, exemplified by the extant (Alopochen aegyptiaca), exhibit a primarily herbivorous diet dominated by seeds, green vegetation, and grasses, with terrestrial plants accounting for the majority—often over 90% during the —of their intake. They also consume aquatic plants such as Potamogeton pectinatus and crop shoots like and corn, particularly in agricultural areas, which can lead to conflicts with farmers. Opportunistically, they ingest animal matter including (such as locusts and alates), worms, and small aquatic invertebrates, though this forms a minor portion of the diet. Foraging occurs mainly on land through and pecking, with birds grasping stems mid-height, bending them, and cropping with the lower , or by dabbling in shallow for aquatic vegetation. Activity is diurnal, peaking in the early morning and late afternoon, and individuals forage in pairs or small flocks, though larger groups of up to 2,000 have been observed in resource-rich Ethiopian wetlands. Egyptian geese dedicate about 33% of their daytime to , preferring open habitats like short-grass pastures, grasslands, and arable fields near bodies. Dietary composition shows seasonal variation, with a greater reliance on matter like grasses during the (over 93% of observations) and increased consumption in the when are more abundant. Goslings initially prioritize small aquatic before shifting to -based . There is no evidence of ; remains shallow and surface-oriented. For the extinct island species of Alopochen, such as the (Alopochen mauritiana), dietary habits are inferred to have been similar, centered on terrestrial in habitats, supplemented by small , based on their ecological niches in wetland-adjacent open areas.

Alopochen species form monogamous pairs that often last for life, with pair bonds typically established through displays in nonbreeding flocks. involves vocalizations and physical behaviors, including loud calling by females to attract males, who respond with erect postures, wing-flashing to expose white underwing coverts, ceremonial drinking or swimming, and wing-spreading displays; copulation occurs in shallow water and is preceded by head dipping. Males perform noisy, elaborate routines featuring hissing or snarling, neck stretching, and feather displays to attract mates, and they exhibit high aggression during mating, including fights with biting and striking using carpal knobs. In Africa, breeding for the extant Egyptian goose (Alopochen aegyptiaca) timing varies geographically but often occurs from July to March, typically starting at the end of the dry season so that goslings benefit from food availability during the rainy season; in southern regions, it may peak from March to June, though it can extend from January to July with peaks in March to May; outside native ranges, such as in Florida, breeding is year-round with multiple broods possible. Pairs are generally single-brooded but may produce a second clutch in favorable years. Nesting is opportunistic, utilizing tree cavities, ground burrows, rocky ledges, or artificial sites near water, often on small islands; the female lines the nest with grasses, leaves, and down feathers. Clutch sizes range from 5 to 12 eggs (mean around 7 in southern Africa), laid at intervals of 1–2 days. Incubation lasts 28–30 days and is performed primarily by the , who covers the eggs with down when leaving the nest, while the stands sentry nearby. Goslings are precocial, leaving the nest immediately after hatching, at which point both parents lead them to and provide ; the broods the young while the guards against intruders, and pairs aggressively defend through physical confrontations, including aerial pursuits resembling dogfights. Fledging occurs at 60–70 days, after which family groups may join larger flocks, and territorial aggression often extends to securing foraging areas adjacent to nesting sites. For the extinct island species, such as the (Alopochen mauritiana) and (Alopochen kervazoi), reproductive biology is inferred to have been similar to the extant species, with adaptations likely favoring ground or cliff-edge nest sites on oceanic islands lacking large trees; no subfossil evidence exists for clutch sizes or specific behaviors.

Conservation

Status of the Egyptian goose

The Egyptian goose (Alopochen aegyptiaca), the only extant species in its genus, is classified as Least Concern on the due to its large global population and extensive range across and parts of the . Although precise estimates are lacking, the native African population is estimated at least 500,000 individuals and is overall decreasing, though stable or increasing in some regions due to adaptations to human-modified landscapes. In its native range, the species faces primary threats from persecution through shooting and poisoning as an agricultural pest, and hunting for sport; habitat loss driven by agricultural expansion also fragments wetlands and grasslands essential for foraging and breeding. Disease risks, such as avian influenza transmission near poultry farms, are minor but present, though the species' resilience limits broader impacts. Outside its native distribution, the Egyptian goose has become invasive in following introductions in the mid-20th century, leading to its inclusion on the European Union's list of Invasive Alien Species of Union Concern in 2017 under Regulation (EU) No 1143/2014. In introduced ranges, it competes aggressively with native waterfowl for nesting sites and food resources, displaces species like ducks and swans, and causes economic damage through consumption and grassland fouling. Management efforts include targeted culling and hunting programs in countries like the and the to curb population growth and mitigate ecological harm. Population trends in introduced areas show rapid expansion, with monitoring via national bird atlases revealing increases such as over 10,000 individuals in the UK (a 100% rise over the decade to 2023/24) and approximately 100,000 in the Netherlands. These dynamics highlight the species' adaptability but underscore the need for ongoing surveillance to balance conservation in native habitats with control in non-native ones.

Extinction of island species

The extinction of the three island-endemic in the genus Alopochen—the (A. mauritiana), the (A. kervazoi), and the Malagasy shelduck (A. sirabensis)—was primarily driven by anthropogenic factors following European of the islands. Common causes included intensive human hunting for food and feathers, introduction of predatory mammals such as cats and rats that targeted eggs and chicks, and through clearance for agricultural plantations, which degraded wetlands and foraging areas essential to these ground-nesting waterfowl. The , endemic to , suffered rapid decline after Dutch settlement in 1638, with historical accounts describing it as plentiful in 1681 but increasingly rare due to overhunting for meat. Predation by introduced cats further exacerbated losses, particularly to vulnerable ground nests. The last confirmed records date to the 1690s, with the considered extinct by 1698, as no individuals could be located despite searches. Similarly, the on island faced intense pressure from French colonists starting in the 1660s, who overhunted waterfowl unsustainably, as noted in early complaints about depleting populations. Introduced predators likely preyed on eggs and young, contributing to the collapse. The final sightings occurred between 1671 and 1672, and by 1710, the species was reported as extinct, with no subsequent records. The Malagasy shelduck, known only from subfossil remains in central sites like , underwent prehistoric approximately 1,000–1,400 years ago, coinciding with early around 500–1,000 CE and subsequent . Likely causes included overhunting by arriving and drainage of wetlands for , which eliminated critical habitats; no direct historical accounts exist, but subfossils confirm its taxonomic distinction as a full related to other Alopochen. No conservation or recovery efforts have been undertaken for these , as they are documented solely through subfossils and limited historical descriptions, rendering revival attempts currently unfeasible due to incomplete genetic material and ecological uncertainties.

References

  1. https://www.cabidigitallibrary.org/doi/full/10.1079/cabicompendium.94205
  2. https://datazone.birdlife.org/species/factsheet/egyptian-goose-alopochen-aegyptiaca
  3. https://animaldiversity.org/accounts/Alopochen_aegyptiaca/
  4. https://birdsoftheworld.org/bow/key-to-scientific-names/search?q=alopochen
  5. https://www.avesdecostarica.org/uploads/7/0/1/0/70104897/scientific-bird-names.pdf
  6. https://irmng.org/aphia.php?p=taxdetails&id=1026915
  7. https://www.biodiversitylibrary.org/content/part/BSBHS/27/article-423.pdf
  8. https://animaldiversity.org/accounts/Alopochen_aegyptiaca/classification/
  9. https://www.fws.gov/sites/default/files/documents/Ecological-Risk-Screening-Summary-Egyptian-Goose.pdf
  10. https://birdsoftheworld.org/bow/species/egygoo/cur/systematics
  11. https://doi.org/10.1016/S1055-7903(02)00019-2
  12. https://avibase.bsc-eoc.org/species.jsp?avibaseid=DA2F24E310CF72A6
  13. https://datazone.birdlife.org/species/factsheet/mauritius-shelduck-alopochen-mauritiana
  14. https://datazone.birdlife.org/species/factsheet/reunion-shelduck-alopochen-kervazoi
  15. https://recentlyextinctspecies.com/anseriformes-waterfowl/alopochen-sirabensis
  16. https://recentlyextinctspecies.com/anseriformes-waterfowl/alopochen-mauritiana
  17. https://birdsoftheworld.org/bow/species/egygoo/cur/appearance
  18. https://www.allaboutbirds.org/guide/Egyptian_Goose/overview
  19. https://www.ebsco.com/research-starters/science/egyptian-goose
  20. https://www.researchgate.net/publication/271326342_Family_Anatidae_ducks_geese_and_swans
  21. https://digitalcommons.usf.edu/cgi/viewcontent.cgi?article=2237&context=ffn
  22. https://www.researchgate.net/publication/259188140_A_Study_of_Moult-Site_Fidelity_in_Egyptian_Geese_Alopochen_aegyptiaca_in_South_Africa
  23. http://julianhume.co.uk/wp-content/uploads/2010/07/Review-Holocene-wildfowl-extinctions-Young-et-al.pdf
  24. https://a-dinosaur-a-day.com/post/177282595085/alopochen
  25. https://birdsoftheworld.org/bow/species/egygoo/cur/demography
  26. https://www.bird-lens.com/2023/03/08/egyptian-goose-an-invasive-species-in-europe/
  27. https://circabc.europa.eu/sd/a/71b7fd4a-bcb3-47b8-8969-61dbd5cc0acb/TSSR-2016-003%2520Alopochen%2520aegyptiaca.pdf
  28. https://www.researchgate.net/publication/367746165_Diurnal_activity_patterns_habitat_use_and_foraging_habits_of_Egyptian_goose_Alopochena_egyptiacus_Linnaeus_1766_in_the_Boyo_wetland_southern_Ethiopia
  29. https://birdsoftheworld.org/bow/species/egygoo/cur/foodhabits
  30. https://app.birda.org/species-guide/325/Egyptian_Goose
  31. https://app.mybirdbuddy.com/birds/mauritius-shelduck/5831ffb4-5c39-48e6-aded-001d932ca2c6
  32. https://birdsoftheworld.org/bow/species/egygoo/cur/behavior
  33. https://www.allaboutbirds.org/guide/Egyptian_Goose/sounds
  34. https://birdsoftheworld.org/bow/species/egygoo/cur/breeding
  35. https://uniquebird.com/pages/egyptian-goose-photos-scientific-facts-interesting-details-common-questions
  36. https://a-z-animals.com/animals/egyptian-goose/
  37. https://www.iasregulation.be/377/download
  38. https://www.npws.ie/news/european-union-eu-updates-its-list-invasive-alien-species-union-concern
  39. https://phys.org/news/2024-10-egyptian-geese-wings-france-threatening.html
  40. https://apuedge.com/egyptian-geese-why-a-non-native-species-can-cause-problems/
  41. https://invasivespeciesni.co.uk/wp-content/uploads/2021/10/IUCN-Datasheet-Alopochen-aegyptiaca-Egyptian-goose.pdf
  42. https://www.bto.org/sites/default/files/wituk-2023-24-report-bto-jncc-rspb-naturescot.pdf
  43. https://onlinelibrary.wiley.com/doi/10.1002/jqs.3096
Add your contribution
Related Hubs
User Avatar
No comments yet.