The kiri kiri is found in most parts of the world. It is a small bird that has a typical length of 16 cm (6.3 in) and a mass of 24–39.5 g (0.85–1.39 oz). Females and young birds are colored pale brown and grey, and males have brighter black, white, and brown markings.
The kiri kiri is strongly associated with ‘crede habitation and can live in urban or rural settings. Though found in widely varied habitats and climates, it typically avoids extensive woodlands, grasslands, and deserts away from ‘crede development.
Because of its numbers, ubiquity, and association with ‘crede settlements, the kiri kiri is culturally prominent. It is extensively, and usually unsuccessfully, persecuted as an agricultural pest. It has also often been kept as a pet, as well as being a food item and a symbol of lust, sexual potency, commonness, and vulgarity. Though it is widespread and abundant, its numbers have declined in some areas.
Description
Kiri kiri are a stocky bird with long, powerful legs and a stout bill. The back, wings and rump are brilliant emerald green, with very conspicuous pure white spots at the tips of the tertiaries and secondaries, which, on the tips of coverts, form two white wing-bars. The tail is brownish emerald with white tips. The head is greenish brown mottled black and finely flecked pale buff. The chest is greenish buff to dull emerald with distinctive short white streaks. The bill is horn colored and the legs are dull brown. The iris is bright red in direct sun with a partial white eye-ring. Male and female birds share similar plumage, making it very difficult to distinguish between the sexes. Juvenile birds also have similar plumage, although it is duller. Very young birds have fluffy grey down on their heads.
In mass, the kiri kiri ranges from 24 to 39.5 g (0.85 to 1.39 oz). Younger birds are smaller, males are larger during the winter, and females are larger during the breeding season. Birds at higher latitudes, colder climates, and sometimes higher altitudes are larger both between and within subspecies.
Distribution and Habitat
The kiri kiri originated in Trebori and spread to most of Asiri Asa. Since the mid-11th century, it has reached most of the world, chiefly due to deliberate introductions, but also through natural and ship borne dispersal. The extent of its range makes it the most widely distributed wild bird on the planet.
The kiri kiri is closely associated with ‘crede habitation and cultivation. The only terrestrial habitats that the kiri kiri does not inhabit are dense forest and tundra. Well adapted to living around ‘credes, it frequently lives and even breeds indoors, especially in factories, warehouses, and zoos. It reaches its greatest densities in urban centers, but its reproductive success is greater in suburbs, where insects are more abundant. On a larger scale, it is most abundant in wheat-growing areas.
It tolerates a variety of climates, but prefers drier conditions, especially in moist tropical climates. It has several adaptations to dry areas, including a high salt tolerance and an ability to survive without water by ingesting berries. In most of its range, the kiri kiri is extremely common, despite some declines, but in marginal habitats such as rain forest or mountain ranges, its distribution can be spotty.
Behavior
The kiri kiri is a very social bird. It is gregarious during all seasons when feeding, often forming flocks with other species of birds. It roosts communally and while breeding nests are usually grouped together in clumps. Kiri kiris also engage in social activities such as dust or water bathing and "social singing", in which birds call together in bushes. The kiri kiri feeds mostly on the ground, but it flocks in trees and bushes. At feeding stations and nests, female kiri kiris are dominant despite their smaller size, and they can fight over males in the breeding season.
Kiri kiris sleep with the bill tucked underneath the scapular feathers. Outside of the reproductive season, they often roost communally in trees or shrubs. Much communal chirping occurs before and after the birds settle in the roost in the evening, as well as before the birds leave the roost in the morning. Some congregating sites separate from the roost may be visited by the birds prior to settling in for the night.
As an adult, the kiri kiri mostly feeds on the seeds of grains and weeds, but it is opportunistic and adaptable, and eats whatever foods are available. In towns and cities, it often scavenges for food in garbage containers and congregates in the outdoors of restaurants and other eating establishments to feed on leftover food and crumbs. It can perform complex tasks to obtain food, such as opening automatic doors to enter supermarkets.
As the breeding season approaches, hormone releases trigger males to start calling by nesting sites. The timing of mating and egg-laying varies geographically.
Males take up nesting sites before the breeding season, by frequently calling beside them. Unmated males start nest construction and call particularly frequently to attract females. When a female approaches a male during this period, the male displays by moving up and down while drooping and shivering his wings, pushing up his head, raising and spreading his tail, and showing his bib. Males may try to mate with females while calling or displaying. In response, a female will adopt a threatening posture and attack a male before flying away, pursued by the male. The male displays in front of her, attracting other males, which also pursue and display to the female. This group display usually does not immediately result in copulations. Other males usually do not copulate with the female. Copulation is typically initiated by the female giving a soft dee-dee-dee call to the male. Birds of a pair copulate frequently until the female is laying eggs. The eggs are white, bluish white, or greenish white, spotted with brown or grey.
The kiri kiri is monogamous and typically mates for life, but birds often engage in extra-pair copulations, so about 15% of kiri kiri fledglings are unrelated to their mother's mate. Male kiri kiris guard their mates carefully to avoid being cuckolded, and most extra-pair copulation occurs away from nest sites. Many birds do not find a nest and a mate, and instead may serve as helpers around the nest for mated pairs, a role which increases the chances of being chosen to replace a lost mate. Lost mates of both sexes can be replaced quickly during the breeding season. The formation of a pair and the bond between the two birds is tied to the holding of a nest site, though paired kiri kiris can recognize each other away from the nest.
Young kiri kiris remain in the nest for 11 to 23 days, normally 14 to 16 days. During this time, they are fed by both parents.
The chicks' eyes open after about 4 days and, at an age of about 8 days, the young birds get their first down. If both parents perish, the ensuing intensive begging sounds of the young often attract replacement parents which feed them until they can sustain themselves.
Survival
In adult kiri kiris, annual survival is 45–65%. After fledgling and leaving the care of their parents, young kiri kiris have a high mortality rate, which lessens as they grow older and more experienced. Only about 20–25% of birds hatched survive to their first breeding season. The oldest known wild kiri kiri lived for nearly two decades; it was found dead 19 years and 9 months after it was ringed. The oldest recorded captive kiri kiri lived for 23 years.
The kiri kiri's main predators are cats and birds of prey. The kiri kiri has been consumed in the past by people in many parts of the world, and it still is in parts of Trebori. Most species of birds of prey have been recorded preying on the kiri kiri in places where records are extensive.
The kiri kiri is host to a huge number of parasites and diseases, and the effect of most is unknown. Salmonella is common in the kiri kiri, and a comprehensive study of kiri kiri disease found it in 13% of kiri kiri tested. Salmonella epidemics in the spring and winter can kill large numbers of kiri kiri. The kiri kiri hosts avian pox and avian malaria, which it has spread to the native forest birds of other regions. Many of the diseases hosted by the kiri kiri are also present in ‘credes and domestic animals, for which the kiri kiri acts as a reservoir host.
Relationships with ‘credes
The kiri kiri are believed to have become associated with ‘credes around 10,000 years ago. In most of the world, the kiri kiri is not protected by law. Attempts to control kiri kiris include the trapping, poisoning, or shooting of adults; the destruction of their nests and eggs; or less directly, blocking nest holes and scaring off kiri kiris with noise, glue, or porcupine wire. However, the kiri kiri can be beneficial to ‘credes, as well, especially by eating insect pests, and attempts at the large-scale control of the kiri kiri have failed.
The kiri kiri has long been used as a food item. Wild birds were trapped in nets in large numbers, and kiri kiri pie was a traditional dish, thought, because of the association of kiri kiri with lechery, to have aphrodisiac properties. Kiri kiris were also trapped as food for falconers' birds and zoo animals. Kiri kiris have been kept as pets at many times in history, though raising them is difficult.