Birds That Pair For Life

Geese have some traits resembling those of humans, i.e. stable pairing. These intelligent birds are faithful to each other for life. If either of the two dies, the surviving bird will remain single for a long time, or even for life and would take no other mate. Usually they nest away from other birds and in most cases only the females build nests and incubate. When she has to leave nest to forage, it covers the eggs with down which it plucks from her breast. They also have close family ties. Goslings, even if they are grown up, do not leave their parents.

The world population of many species of geese has declined drastically in last 50-60 years. They had to face large-scale persecution not only during the breeding season but also in their wintering grounds, which are far from their nesting places in totally different countries.

The population of bean goose (Anser fabalis) has also dwindled in recent years throughout its distribution range, except in Iceland where an estimated population is about 70,000. It breeds in the Arctic regions of Asia, Europe and the coasts of Greenland. In Europe its wintering grounds are in the western and southern parts.

At beginning of the last century some four lakh (four hundred thousand) of Brent geese (Branta bernicla) wintered in Europe, whereas by the end of 1940s, only 25,000 remained. In 1931, according to an estimate, an average of 11,000 birds wintered in Holland, but in 1953 there were only 1,000. In Denmark their number went down from 8,000 to about 1,500. In America the population comprises 90 per cent of the world population, estimated number being 1.80 lakh (180 thousand), which is not very much. These birds breed in the arctic tundra of Asia, Europe and North America.

Fooled To Lay More Eggs

Mallard pair (CC BY - SA 2.5)

Mallard or wild duck (Anas platyrhynchos) is one those birds that can be fooled into laying, much beyond their normal clutch-size by removing their eggs as they are laid. In this way, mallards were fooled to lay, up to 146 eggs! Normally birds lay a clutch of 8-13 eggs.

Like many other species, females of this duck are also able to communicate with their chicks even when they are not hatched. During incubation or brooding they emit a species-specific maternal call, which unhatched ducklings listen, understand and respond. The instinct of the mother tells her, when to communicate. It starts making the call when in-embryo duck’s head projects into the airspace of the egg, about 17 to 19 days after laying. It helps ducklings to recognize the call, which they will hear in the near future after coming out of the shell.

These ducks usually form pairs (in October and November in the Northern hemisphere) only until the female lays eggs at the start of nesting season which is around the beginning of spring, at which time she is left by the male who joins up with other males to await the moulting period which begins in June (in the Northern hemisphere). During the brief time before this, however, the males are still sexually potent and some of them either remain on standby to sire replacement clutches (for female Mallards that have lost or abandoned their previous clutch) or forcibly mate with females that appear to be isolated or unattached regardless of their species and whether or not they have a brood of ducklings.

The nesting period can be very stressful for the female since she lays more than half her body weight in eggs. She requires a lot of rest and a feeding/loafing area that is safe from predators. Eggs, which are incubated for 27–28 days to hatching with 50–60 days to fledgling. The ducklings are precocial and fully capable of swimming as soon as they hatch.

The male birds (drakes) have a glossy green head and are grey on wings and belly, while the females have mainly brown-speckled plumage. Mallards live in wetlands, eat water plants and small animals, and are gregarious. This species is the ancestor of most breeds of domestic ducks. The name mallard is derived from the Old French malart or mallart "wild drake", although its ultimate derivation is unclear.

Belonging to the subfamily Anatinae of the waterfowl family Anatidae, these birds are killed in large numbers. In 1984 alone, it was among the most commonly shot bird in the USA, when 3,954,100 mallards were killed whereas the number in the following year was 3,234,800.

Besides shooting, they also die in large number due to lead poisoning. Usually they are poisoned through anglers’ discarded or lost split-shot and shooters’ discarded shotgun pellets. These birds along with some other species of dabbling ducks are especially attracted to these pellets because they feed largely on hard, round seeds of aquatic plants, which resemble pellets. Destruction caused due to lead poisoning can well be judged by the fact that on one occasion in Illinois (USA) 110,000 mallards died because of lead poisoning.

Mallards breed throughout the temperate and subtropical Americas, Europe, Asia, and North Africa, and has been introduced to New Zealand, Australia, Peru, Brazil, Uruguay, Argentina, Chile, the Falkland Islands and South Africa.