Waterfowl Words

A glossary of words you may encounter in relation to waterfowl.

AOC: Any Other Colour

AOV Any Other Variety

Abdomen: the lower body (below the thorax) from keel to vent. 

Air sacs: thin-walled, transparent sacs extending from the mesobronchi or the lungs to different regions of the body; they act as bellows to bring air into the body and store it until expiration. They are found only in birds.

Air space: cavity formed between the outer and inner shell membranes in the egg. Expands in the developing egg as air replaces water vapour lost during incubation.

Albumen: egg white; consists mainly of proteins.

Allele: a possible form of a gene at a single locus.

Allopreening: social grooming between birds, often stengthening the pair bond. The White-faced Whistling Duck is a great example.

Altricial: born naked and helpless.

Alula: bastard wing; vestigial bone group, often much reduced, equivalent to the thumb. Covers the anterior edge of the wing at the carpal joint. 

Anterior: toward the front.

Anseriformes: the order of birds known as the waterfowl, comprised of 3 families; Anhimidae (three species of screamers), Anseranatidae (the magpie goose), and Anatidae (the ducks, geese, swans).

Auto-sexing: sexual dichromatism in the plumage; males a different colour or pattern from the female. This trait is usually visible straight after hatxhing.

Bacteria: single celled microscopic organisms. Many are capable of producing disease, others are essential to healthy life.

Bar: a narrow horizontal stripe across a feather.

Bean: raised, hard oval protuberance on the end if the upper mandible. Also called the nail.

Bib: distinct patch of white (or coloured) feathers coverting the lower neck, front and breast.

Biosecurity: measures taken to minimise the risk of infectious diseases caused by viruses, bacteria or other microorganisms entering, emerging, establishing or spreading.

Blood feather: the emerging feather from the skin follicle, still covered by the keratin sheath. As the feather erupts it has a significant blood supply within the sheath, allowing it to grow quickly. As the feather lengthens the blood supply dries up. Whilst in the early stages of growth, any damage can cause a significant bleed, hence it is prudent not to catch up birds at this time and risk damage.

Breast: ventral area of the thorax or chest. 

Breed: variety with genetically stable phenotype.

Brood patch: bare patch of skin on the abdomen which is rich in blood vessels; transfers heat from the bird to eggs during incubation.

Candling: shining a light through the eggshell to view the contents and development.

Carpal joint: equivalent to the wrist, the most forward part of the folded wing. Some species have bony projections known as carpal spurs, used in disputes over territory and mates. 

Carriage: angle of the body held in a natural stance, relative to horizontal. 

Cere: coloured bare skin at the base of the upper mandible, containing the nostrils

Chalazae: twisted albumen proteins that help to suspend the egg yolk within the albumen.

Chromosomes: threads of DNA found in the nucleus of a cell; containing the genetic instructions for the organism.

Cilium: orbital ring; bare part of eyelids.

Cloaca: cavity into which the gut, ureters and reproductive organs open.

Clutch: batch of eggs produced by an individual bird for one cycle of incubation.

Cob: male swan

Collar: band of colour partially or completely encircling the neck. 

Contour feathers: outer layer of feathers forming a streamlined and weatherproof coat. 

Crèche: group of young birds being cared for in a group. Some species combine families and caring responsibilities. Eider and Common Shelduck are good examples.

Crepuscular: most active at dawn and dusk.

Crest: feathers above the upper surface of the cranium. 

Crown: upper part of the head, above the forehead. 

Culmen: dorsal ridge of the upper mandible, running from the tip to the base. 

Cuticle: outermost layer on avian eggshell, or outer skin covering the beak.

Cygnet: young swan

Diploid: cell containing a set of paired chromosomes.

Dimorphism: a trait that occurs in two distinct forms or morphs within a given species. Where males and females are different in appearance, we term them sexually dimorphic.

Distal: furthest from the centre; at the end.

Diurnal: active during the day.

DNA: deoxyribonucleic acid; a double chain molecule, fundamental substance of which genes are composed.

Dominant: bird in a group controlling or prevailing over all others. In genetics: an allele whose effect is not blocked by its alternative form.

Dorsal: upper surface.

Down: natal plumage of precocial young, or insulating fluffy feathers under the contour layer. Usually lacking a stem or stiff rachis. 

Drake: male duck.

Dump nesting: birds deliberately laying eggs in the nest of another, usually of the same species but not always. In some situations, it may be due to a lack of suitable nest sites. Laying eggs in the nest of another is known as parasitism, such as the Black-headed Duck.

Eclipse: post-breeding summer plumage of males of certain species. Cryptic and often resembling the female. Also known as basic plumage. 

Egg tooth: hard point on the tip of the beak used in hatching. Usually drops off as the chick starts to grow. Not present in ratites.

Embryo: early stage of development from fertilisation to hatching.

Enrichment: provision of elements to provide mental stimulation for kept species. 

Enzyme: biological catalyst.

Epistatic: masking of the phenotypic effect of alleles of one gene by alleles of another gene. Epistatic genes are sometimes called inhibiting genes because of their effect on others.

External pipping: first break of the shell from inside during hatching.

Eye-ring: fine feathers immediately surrounding the eye. 

Eyebrow: light-coloured line above the eye. 

Eyelines: dark lines resembling reins across a face, one from the top of the bill, through and beyond the eye, the other from the bottom of the bill arcing below the eye. Obvious in Mallard females. 

Eyestreak: area of light-coloured plumage between the eyelines. 

Fertilisation: union of spermatozoon and ovum.

Five Freedoms: the gold standard in animal welfare, encompassing both the mental and physical well-being of animals; freedom from hunger and thirst; freedom from discomfort; freedom from pain, injury, and disease; freedom to express normal and natural behavior; and freedom from fear and distress.

Five Domains: identifying and grading areas relating to the Five Freedoms as ‘Five Domains’ of nutrition, environment, health, behaviour and mental state.

Flank: side of the body between the ribs and the hip. 

Flights or flight feathers: long, stiff, asymmetrically shaped feathers on the wings and tail. Light, but stiff enough to enable flight.

Flyway: major route taken by migrating birds, usually between breeding grounds and overwintering sites. Any given species travels roughly the same route every year, at near-identical times annually.

Gander: male goose

Gape: soft mouth of a bird, between the upper and lower mandibles.

Gene: a section of DNA which passes information to the next generation; the basic unit of inheritance.

Genotype: genetic constitution of an organism.

Haploid: cell containing a set of single chromosomes.

Hardware disease: birds picking up miscellaneous bits of metal (usually) found in their enclosure. Sharp shards can puncture the oesophagus or gizzard and drift to other parts of the body. Other internal injuries and blood poisoning are often fatal.

Hatchling: young bird in the first few days after hatching.

Heterozygous: a gene pair having different alleles at a single locus.

Homozygous: a gene pair of 2 identical alleles at a single locus.

Inbreeding: The mating of closely related individuals within a population. The greater the degree of inbreeding, the greater the chance that deleterious genetic traits will occur in the population.

Infundibulum: open top of the oviduct.

Integument: covering or outer layer; in birds, usually refers to feathers.

Iridescence: metallic appearance of feathers caused by refracted light. 

Irruptive species: a species that irregularly moves to an area in which it is not usually found.

Lamellae: 1. Thin layers, plates, or membranes, such as the calcified layers of which bone is formed.

2. Tooth-like serrations at the side of the beak. Allow filtering of small food particles, as in shovelers, or improving the grip on prey, such as seen in the saw-billed ducks.

Lethal gene: a gene which may result in the death of the individual expressing it.

Locus: specific place of a gene on a chromosome.

Loral spot: obvious small patch immediately behind the bill. 

Mandible: upper and lower bill sections.

Medial: to the middle.

Migration: seasonal movement of populations, often along a specific flyway, between breeding and wintering areas. The annual cycle is predictable. Short-range migration also happens in response to local conditions, such as weather and availability of water or food.

Nidicolous: staying in the nest for a long time because of the dependance on the parents for food, protection and the learning of survival skills.

Nidifugous: fully feathered and leaving the nest soon after hatching.

Nocturnal: active in the hours of darkness.

Nuchal: referring to the rear of the head.

Ovary: female reproductive organ.

Oviduct: tube where eggs are formed as they pass from ovary to cloaca.

Palmate: the most common type of webbed feet found in ducks, geese, swans, gulls, terns, and other aquatic birds. Three toes or more are completely webbed, enabling an efficient propulsion through water.

Pathogen: agent which causes disease.

Pen: female swan.

Phenotype: outward appearance of an organism.

Pin feathers: young growing feathers still protected by the quill. Whilst ‘in pin’ there is a blood supply to the growing feather. If damaged, the quill can bleed. See also Blood feather.

Pipping: point when the hatching bird first breaks the shell from the inside. Internal pipping is when the hatchling breaks through the internal membrane and starts to breathe air. 

Posterior: to the rear.

Precocial: fully feathered and active, able to feed soon after hatching.

Preen gland: uropygial gland; situated at the base of the tail, producing oil to condition the feathers. Present on most birds but notable exceptions are Amazon parrots, kiwis and ostriches.

Primaries: The main flight feathers found on the outer part of the wing and forming the ‘hand’.

Rachis: central stem of a feather. 

Recessive: an allele whose effect is blocked by its alternative form.

Relative humidity: amount of water vapour in the air as a percentage of saturation value for water vapour at any given temperature.

Remiges: primary, secondary and tertiary wing feathers. Usually vanes are unequal widths either side of the central shaft. 

Retrice: tail feather.

Rump: the part of the body immediately above the tail, in some species distinctly coloured

Saturation: maximum amount of water vapour that air can hold.

Scapulars: feathers above the shoulder, usually shielding a large area of the wings when folded. 

Scrape: impression in the ground, often the first stage of ground nest building.

Secondaries: the relatively large flight feathers that form the inner part of the wing.

Setting: placing in the incubator.

Sex chromosome: chromosome which plays a part in sex determination. The avian genome contains W and Z chromosomes — females are ZW and males are ZZ.

Sexual dimorphism: difference in appearance between males and females. Often, but not always, the male is more brightly coloured. There is also sometimes a size difference.

Speculum: a patch, often distinctly coloured, on the secondary wing feathers of some birds

Starter crumbs: manufactured food for young fowl. 

Sub-adult: adult-like plumage but retaining some immature features.

Testes: male reproductive organ.

Thorax: part of the body enclosed by ribs.

Vent: area underneath the tail, covered by the undertail coverts.

Vent sexing: commonly used to sex waterfowl; males have a phallus, which can be seen on gentle manipulation of the cloaca in most species. The technique should be learned from a proficient keeper.

Ventral: lower surface.

Vitelline membrane: fine fibrous membrane surrounding the yolk.

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Weight loss: measure of weight lost to evaporation in the egg. Water vapour is replaced by air in the air sac, its size is an indication of progress.

Wet bulb thermometer: temperature probe covered by a saturated wick. Used in conjunction with a dry bulb thermometer to measure relative humidity.

Yolk: spherical body in the egg, supplying nutrients for the embryo.

Zoonotic: An infectious disease that is transmitted from animals to humans or vice versa.

Zygote: product of fusion of female ovum and male sperm.