Pink cockatoo
| Pink cockatoo | ||||||||||
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Pink Cockatoo, female |
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| Systematics | ||||||||||
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| Scientific name | ||||||||||
| Eolophus roseicapilla | ||||||||||
| ( Vieillot , 1817) |
The Galah ( Eolophus roseicapilla , Syn. : Cacatua roseicapilla ), and occasionally in the acquisition of the Australian name Galah called, is one in Australia widespread and frequent parrot . The pink cockatoo is a medium-sized, stocky built cockatoo with a striking pink and gray colored plumage. The hood is short and directed backwards. The long wings reach almost to the tip of the slightly rounded tail. The pink cockatoo is the only member of the genus Eolophus .
The range and density of the pink cockatoo has increased over the past few decades. Both can be traced back to changes in their habitat by humans, who create new feeding areas for the pink cockatoo by converting arid areas into agricultural areas with sheep, wheat and maize cultivation. Their spread and increase in population have a negative impact on the population density of other cockatoo species such as the Carnaby's white-eared black cockatoo and the Inca cockatoo . The pink cockatoo is protected in Northern Australia. In other Australian regions it is considered a pest that is often released for shooting. Pink Cockatoos occasionally appear in large flocks and can cause considerable damage in grain fields. The great agricultural damage caused the Australian authorities to commission extensive research into the way of life of the cockatoo as early as 1969. The pink cockatoo is therefore one of the best-researched parrot species today.
Pink cockatoos are popular aviary birds and were among the most frequently traded large parrots until around 1945. They were first imported to Europe in 1843. The first breeding succeeded as early as 1876. However, since large numbers of these cockatoos were brought into the trade as wild-caught ones, there was no systematic breeding. Since the Australian government banned the export of all domestic animal species, pink cockatoos have become a coveted rarity in the bird trade outside of Australia. When the breeding pairs were compiled since the export ban, the status of the subspecies has often not been taken into account, so that the pink cockatoos kept in Europe and North America are mixed forms of the subspecies. Pink cockatoos are very long-lived birds that are demanding to care for. They can live to be more than 40 years old in captivity.
description
Pink cockatoos reach a body length of 35 centimeters and a weight between 200 and 380 grams. The males weigh between 272 and 380 grams. In females, the weight ranges from 200 to 356 grams. The wings are rounded and long in relation to body size. The tail is relatively short and square at the end.
The forehead, hood and back of the head of the males are white to light pink. The feathers just below the eye occasionally have a pinkish-white tint at the tips. A narrow front headband, like the reins, is pink. At the back of the head, the light pink of the head merges into the darker pink of the feathers on the neck. The cheeks, the ear area as well as the neck, throat, chin, throat, chest, the under wing coverts and the belly are pink-red. The back, the wings, the upper and lower tail-coverts are gray. This gray is the lightest on the arm covers, the rump and the upper tail covers. In contrast, the coverts, the hand wings and the tip of the tail are clearly darker gray. The beak is brightly horn-colored. The iris is dark brown to black. The legs are gray. The eye-catching eye ring is unfeathered, white to grayish white and wrinkled. The feather bonnet , the most striking feature that distinguishes cockatoos from other parrot species, is only slightly pronounced in the pink cockatoo compared to other cockatoos. It is usually laid flat so that the head appears round. In slightly excited birds, the spring hood is slightly raised at the rear end. When the birds are very excited, the bonnet is widely spread. This is not as noticeable as with other cockatoo species such as the white-hooded cockatoo , but the widely spread feather bonnet has an important signal function in a number of social interactions with other species .
The gender dimorphism is only weak. In females, however, the iris is medium brown to reddish while it is dark brown in males and young birds. This difference is so noticeable from the age of six months that the sexes can be determined with certainty. The eye ring is also narrower and smoother in females. The moulting of the pink cockatoos begins a few weeks after the young birds have flown out and lasts 160 to 180 days. Females start moulting a little later and go through it faster than males.
Newly hatched nestlings have pink down. This distinguishes them from the other cockatoo species, in which most of the nestlings have pale yellow to bright yellow dunes. Fledglings resemble the adult pink cockatoos. However, they are overall duller in color. The forehead, bonnet and crown of the head as well as the chest are also overrun with matt gray. If they sit immobile in the treetops, they are very difficult to make out because of their spotty-looking plumage. The featherless eye ring is pale yellowish white. It still lacks the characteristic wrinkling that is typical of adult birds. In their first autumn, young birds moult their body plumage and can then no longer be distinguished from the adult birds by their plumage.
Locomotion
On the ground or on horizontal branches, pink cockatoos walk by placing one foot in front of the other in a slow, lurching or rolling body movement. This type of movement is probably related to the short length of their tarsometatarsus . The feathered tibiotarsus is only just above the ground when walking. Since pink cockatoos avoid wetting their plumage whenever possible, they rarely stay in higher ground vegetation. In certain sexually or aggressively motivated contacts with other pink cockatoos, they occasionally move sideways by pulling one foot towards the other. So-called promenading, in which pink cockatoos walk on a horizontal branch, first turning their head at the end of the branch and then turning the body abruptly to run in the other direction again, is a behavior stereotype of captive birds that has not yet been observed in the wild has been. When climbing tree tops or in bushes, they often use their beak to pull themselves up.
Pink cockatoos reach a flight speed of 50 to 60 kilometers per hour. Even at high speed, swarms are agile enough to maneuver between the treetops. Their flight pattern differs significantly from the flat and irregular wing beats of the actual cockatoo : Immediately after flying up, the wing beats are initially fast and expansive. As soon as the cockatoos have reached a certain speed and height, the wing beats become a little flatter and the beat rate slows down. Unlike the yellow-hooded or Inca cockatoo, for example, the flight is not interrupted by gliding phases. They only glide in the immediate landing approach. Since they are slow on the ground, they often fly up when they only want to cover short distances. Such short flights can be observed when moving in the treetops or when they want to sit at the head of a swarm of swarms while searching for food on the ground. Pink cockatoos also react to predators with flies. When a bird of prey approaches, they fly up, almost all of the pink cockatoos in the vicinity and then circle at high speed at a height of about 100 meters above the ground. A hatred of the approaching bird of prey, as practiced by various passerines , is lacking in the pink cockatoos. The situation is different when a carnivore living on the ground approaches pink cockatoos. The cockatoos then also fly up, then circling over the prey gripping loudly and following it when it moves.
Pink cockatoos are known for their playful flight acrobatics. They often fly through tree tops at a low altitude and with acrobatic turns and twists, screeching loudly. Ian Rowley reports that it is mainly immature birds that show this behavior before they settle on their resting trees.
voice
As a social bird species, most of the calls serve to establish contact with their conspecifics. It can be the partner bird, a member of the flock or pink cockatoos that do not belong to the flock.
The contact sound is a chill-chill or chet chet . Ian Rowley believes that although sonograms do not show any major differences, this reputation is sufficiently individual that pink cockatoos can be identified by it. This quiet contact call is emitted every ten seconds both on the ground and in flight. If the birds are concerned, the call distance is reduced. A longer cheat , usually repeated two to four times, can be heard when pink cockatoos return to the nesting cavity. The call is usually picked up by the partner bird. A softer kwie is a calming sound that can be heard especially when pink cockatoos come to the nesting hole to feed nestlings. Nestlings beg with hoarse gasping noises. The beak is slightly open, the bonnet spread and the bird sways slightly from side to side. The adult pink cockatoos also let out this panting call when they hand over their food.
With Lik-lik or Lik-lik-lik calls, pink cockatoos indicate that they will be blown. Pink cockatoos in the vicinity often pick up this call, so that an initial call from a bird usually leads to several birds flying up. Scrie calls express a slightly aggressive mood. They can be heard in a variety of situations, such as when a pink cockatoo pinches a neighboring pink cockatoo. But it is also the call that can be heard in hateful situations and can also be heard in territorial behavior.
Distribution area
Pink cockatoos are represented today with three subspecies on the entire continent as well as on Tasmania . Its main area of distribution is the interior of the Australian continent. They are also found on some islands off the Australian coast.
It is not certain to what extent the present-day distribution area differs from that before the Australian continent was settled by European settlers. The ornithologist Ian Rowley assumes that pink cockatoos were originally only found in the interior of Australia. He is convinced that their range was limited in the east by the 3,500 kilometers long Great Dividing Range and in the west by the Kwongan heather. It is undisputed that pink cockatoos significantly expanded their range in the second half of the 20th century and are now also found in the wheat belt in southwest Australia and in the coastal regions. At the same time, their population has risen sharply. Pink cockatoos have benefited from the deforestation of forests and the conversion of the former forest areas into agriculturally used areas. The installation of cattle troughs, which offer water all year round, also gives them the opportunity to colonize arid regions of Australia. They now come in almost all types of open landscape types and have also colonized coastal and highland regions. The colonization of new habitats can happen very quickly. For example, pink cockatoos were rare in the Sydney area until the 1980s. Since then, the population there has increased so much that they are part of the common bird species. Similar cases are well documented for other regions of Australia. Not all ornithologists attribute the sharp increase in population to changes in the Australian landscape due to human influences. They assume that the decreased rainfall in the 19th century led to a population decline, especially in the interior of Australia, from which the species only recovered in the course of the 20th century.
habitat
The habitat of the pink cockatoo are open landscapes, tree-lined savannahs and open grasslands inland. Their natural distribution centers are semi-arid to semi-humid regions. They avoid densely forested areas, rainforests, sandy deserts and are absent in regions with high rainfall. Their height distribution extends up to 1,250 meters above sea level. They have adapted well to urban habitats and are common in parks and gardens.
Fixed breeding pairs are sedentary and have an activity room with their breeding tree in the center. The large flocks, which nomadize in an undirected manner, are composed of not yet sexually mature young birds and a few non-breeding adult birds. As a rule, they use an area that covers 1000 square kilometers. The migratory movements are influenced by the changing availability of feed.
Way of life
Pink cockatoos are social birds that can only be observed in pairs in exceptional cases. They usually roam in small groups. However, the basic unit of their social life is the couple. As a rule, they enter into a monogamous relationship that imagines until one of the birds dies. This pair usually nests in the same breeding tree or at least in neighboring trees for several years. This breeding tree is the center of their activity and they are usually no more than 10 kilometers away from it. The loose swarms they form are made up of the neighboring pairs.
In a study that lived in the wheat belt of Australia in an area of 90 square kilometers 130 breeding pairs. These formed a total of twelve swarms. However, the number of individuals in the flocks was supplemented by nomadic, not yet sexually mature young birds and by non-breeding adult birds. Occasionally, therefore, large flocks form that can contain several thousand birds. Occasionally there are socializations with yellow-hooded , Inca and naked-eye cockatoos . Since pink cockatoos do not have their own warning system, they benefit in particular from the attentive yellow-crested cockatoos and react to their alarm signals with flies.
daily routine
Pink cockatoos are diurnal birds. Your activity phase begins with the first morning light. In the treetop where they spent the night, they first look for the branches that are exposed to the morning sun. They then search the ground around their sleeping trees for a short time. Ian Rowley was unable to find suitable food plants there during his investigations and suspects that they take up small stones in this regularly observed behavior. After spending fifteen to thirty minutes on the ground, they return to the treetops to tend their plumage. A little later, a first pink cockatoo with Lik-lik calls initiates a spirit of optimism. If a sufficient number of cockatoos follow the first bird, the whole group will very quickly leave their sleeping trees and seek out the feeding grounds. If this is not the case, the blown birds return to the treetops. If the feeding grounds are more than a kilometer away from the resting trees, the pink cockatoos rest in trees on the way. They often meet other swarms with whom they fly on to the feeding grounds. Foraging for food takes between half an hour to four to five hours. The length of time it takes to search for food depends on the density of the food available and the individual situation of the cockatoo. Pink cockatoos that have to look after nestlings tend to look for food for significantly longer than their not yet sexually mature conspecifics. During the hottest time of the day, they rest in leafy treetops. There they doze or take care of their plumage. In the afternoon they go to the food grounds again. As soon as they have found enough food, they go to the nearest water point. At sunset they develop a high level of flight activity. With loud calls, they then look for their sleeping trees, which are usually located near the water.
personal hygiene
Pink cockatoos regularly groom their plumage. The feathers are taken individually in the beak and nibbled on. The feet and legs are also nibbled. Like most birds, pink cockatoos have a prickly gland on the top of the base of the tail. This forms an oily secretion that pink cockatoos distribute with their beak throughout their plumage. Pink cockatoos scratch their heads and necks with their claws as they cannot reach these areas with their beak. You run the foot along below the wing. Because of the potential danger from predators at the few watering holes, pink cockatoos bathe very rarely. However, like many parrots, they react very excitedly when it rains. Wide spreading of the wings and the tail is typical, occasionally when it rains they even hang upside down from the branches with their wings wide open.
Gaming behavior
Pink cockatoos are considered to be very playful birds. This is tied to the fact that they display a number of behaviors that are "unproductive" because they are not related to either the acquisition of food or the reproductive drive. This includes their acrobatic flights through the branches of tree tops, which is not a necessary skill for survival given their sparse tree-lined habitat. They show this behavior especially at dusk. There are reports from New South Wales that pink cockatoos specifically seek out wind turbines, sit down specifically on the lowest wind turbine blade and let them be carried upstairs shouting. At the apex of the wind turbine the cockatoos jump off and again fly towards the lowest wind turbine wing. The playful behaviors also include doing gymnastics and sliding down telephone wires. They swing on the wires, hang upside down and flap their wings, screeching loudly.
food
Ingestion
The food intake takes place mainly on the ground and has its main activity in the morning and in the late afternoon. It proceeds quickly, as the pink cockatoos can easily find enough food to meet their daily needs for most of the year. The Australian ornithologist Ian Rowley has therefore called pink cockatoos as a species of parrot that has "a lot of free time". Nomadic flocks of not yet sexually mature young birds or non-breeding adults are tolerated in the food territory.
The foraging of a flock is initiated by the loud calling of individual birds. Shortly afterwards, the first birds are circling above the treetops. When the other cockatoos follow them, the entire flock moves towards the feeding grounds. If the feeding area is more than a kilometer, the swarm puts a rest period in a large tree on the way there. Often there are other swarms there. Large flocks usually consist of only 25 percent mated pink cockatoos whose nesting hole is nearby. The remaining birds are not yet sexually mature annuals and biennials as well as unmated sexually mature birds. Due to their wide nomadic nature, these not yet bound to a nesting cavity are able to use food resources very quickly. They usually stay close to places with plenty of food even during the night, while the mated birds return to their nesting holes all year round.
While feeding on grassland or a stubble field, they keep a distance of at least 20 centimeters from each other. This individual distance is just so great that it is not possible for the birds to bite the neighboring bird. Behind a broad front line are between five and ten rows of other pink cockatoos. Swarms move in the same direction by walking slowly forward. Occasionally, pink cockatoos that have fed in the back row will fly over the feeding swarm and sit in the front line. Vocalizations can usually only be heard while feeding when new birds arrive. At grain silos or road sections with spilled grain, the distance between the individual individuals of the swarm is significantly smaller and is accordingly characterized by the aggressive interactions of individual pink cockatoos. Most of the time, it is the large males who have just arrived who prevail over weaker birds at these limited feeding spots. Only when they have satisfied their first hunger do they allow other birds to eat. Accordingly, significantly more vocalizations can be heard at such points.
food
The diet of pink cockatoos consists of seeds, grains, fruits, berries, roots, flowers, fresh shoots and leaf buds and sometimes also of insects and their larvae. Tree fruits only play a very subordinate role. You need between 15 and 20 grams of seeds per day. Investigations in the Mulga savannahs in western Australia, largely untouched by humans , revealed 16 plant families that played a role in the nutrition of the pink cockatoos. These include grasses , Sauergras- , Fuchsschwanz- , Gänsefuß- , Wunderblumen- , Mollugo- , Portulak-, Kreuzblüten- , mimosa , Storchschnabel- , Raublatt- , Goodenien- and Buckwheat Family and Daisy Family , Carrot and gyrostemonaceae . In southern Queensland , grass seeds of the sweet grass genera Dactyloctenium from the subfamily Chloridoideae as well as Iseilema and Astrebla dominated , making up almost 80 percent of the diet. In some areas, pink cockatoos can contribute to desertification because of their uptake of grass and wild seeds if they are found in large numbers. They have this in common with some other Australian parakeets and finches . However, these do not occur in such large swarms and, due to their smaller body size, have a lower need for food. Ornithologists also point out, however, that the large flocks of sheep in Australia cause far greater damage to the fields.
In the wheat belt of Australia the food composition of the pink cockatoo is significantly different. Here it is common wheat , seed oats and barley that make up more than two-thirds of the diet of the Pinkakdu. The remaining third consists mainly of the seeds of herons' beaks and ´to a small extent from the seeds of the cape dandelion that is naturalized here . Pink cockatoos find grain in the wheat belt almost all year round. They dig up the freshly sown grains as well as the young saplings, later in the year they bend down the stalks of grain on the edge of the fields so that they can get to the grains, some of which are still ripe, and eat the grain that has fallen to the ground during harvest time. The amount of grain left in the fields after harvest can be substantial. The ornithologist Ian Rowley estimated that in 1974 around 106.3 kilograms of grain per hectare of cultivated land remained in the fields. Pink cockatoos also find spilled grain near grain silos, rail loading stations, and along roads during harvest time. They also benefit from the fact that most of the cattle kept in the wheat belt are fed with grain. Usually this feeding takes place in a form that also allows pink cockatoos access. Pink cockatoos also pick non-digested grain residues from the droppings of other animals. For the pink cockatoos living in the suburbs of Perth , for example, where numerous horses are kept, this is an essential source of food in the winter months. The seeds of herons' beaks are of relatively high importance in the diet of the pink cockatoos in the wheat belt of Australia because their seeds are in September and is therefore available before the start of grain ripening. The main hatching time of the pink cockatoos also falls during this period. The relatively soft seeds of the heron's beaks, which are harvested by the pink cockatoos before the split fruit bursts, play a significant role in the nutrition of the nestlings.
Drink
In the wild, pink cockatoos only drink several times in very hot weather and otherwise only ingest water in the evening hours. In the arid regions of Australia there are only a few water holes and predators prefer to lurk their prey at these. The uptake of water is therefore a particularly dangerous situation for the pink cockatoos. Pink cockatoos therefore prefer to land on branches that overhang the surface of the water or on rocks or logs that protrude from the water. Ian Rowley describes how cockatoos eat water even in flight.
Aggressive interactions between pink cockatoos rarely occur at water points, although the individual distance between the individual birds is regularly undercut due to the often limited access. Ian Rowley suspects that because of their exposed situation, the birds are too distracted at these moments to react to their conspecifics.
Reproduction
Pink cockatoos are monogamous birds. The pair bond continues until one of the birds dies. They also show great loyalty to their location, so that sexually mature and mated pink cockatoos rarely move more than 15 kilometers from their nesting hole. Pinkakdus are sexually mature from their third year of life. They show no sexually motivated behavior during the first two years of life.
Breeding season and courtship
The breeding season depends on the distribution area, the amount of precipitation and the food supply. In the south of Australia it falls in the months of July to November, while in the northern regions of Australia pink cockatoos breed in the months of February to May. If the conditions are unfavorable, the brood does not occur at all or only a very small clutch is laid. In years with very favorable conditions, however, the clutches are larger. After losing a brood, pink cockatoos lay a second clutch. However, they only raise one brood per reproductive period.
The mating repertoire of the pink cockatoo, like many other cockatoo species, is not very large. The males approach the females with their hoods up and their posture tense, turning their heads sideways and calling softly. If the female then flies up, the male follows him shouting. If the female remains seated, however, extensive mutual cleaning takes place. They often sit side by side, side by side. Feeding the female by the male, which plays a major role in courtship in some other cockatoo species, also occurs in pink cockatoos, but is relatively rare. The pair bond is strengthened by the two partner birds staying close to each other while they are feeding, sitting next to each other in the resting trees that are visited during the day and returning to their nesting cave in the evening.
The nesting hole
The nest is made in a hollow branch or trunk of a tree. On average, the caves are eight meters above the ground. Pink cockatoos prefer eucalyptus trees near the banks as nesting holes. However, there is also evidence of breeding of couples who used caves in steep slopes or rock walls as nesting holes or who brooded in holes in the ground or in nesting boxes. Since permanently mated pink cockatoos are sedentary birds, they often use nesting holes for several years. Pink cockatoos breed semi-colonial in suitable places with an average cave distance of almost 50 meters.
Pink cockatoos depend on natural nesting holes because they cannot dig the holes themselves. However, the respective nest cavity is prepared for the breeding business by both sexes. One of the typical activities of pink cockatoos is that they gnaw off a wide strip of bark around the cave entrance. In doing so, they expose the cambium, which forms a woody texture after drying out. This noticeable scar is enlarged annually. The reason for this behavior has not been conclusively clarified. They may be used to signal to other birds that the nest box is occupied. Occasionally, an explanation for this behavior is also given that the remaining smooth bark makes it difficult for nest predators such as monitor lizards to get into the nest cavity. Ian Rowley doubts this because he has never seen a monitor lizard that would not have been able to negotiate these bark-free spots on the tree.
Pink cockatoos line the nest hole with eucalyptus leaves. This is a relatively unusual behavior among cockatoos - other cockatoos usually only carry pieces of wood into the nesting cavity. This behavior probably contributes to the increase of the humidity in the brood cavity and protects the eggs from drying out in the hot, dry climate of Australia. According to the investigations of Ian Rowley, the sometimes meter-thick layer of eucalyptus leaves also reduces the fact that the nest floods when it rains and the clutch thereby dies.
Since pink cockatoos are close to their breeding caves and defensive birds all year round, the loss of caves to other species is only about five percent annually. Among the species that use caves, previously served in the years Galahs as Nisthöhle include Halsbandkasarkas , greybeard hawks , Carnaby's white-tailed Black Cockatoos , mountain parakeets , cockatiels , ring parakeets , Boobookkäuze , barn owls , mane goose , hustler cockatoos , tree Schwalme and feral honeybees .
Territorial behavior
.JPG)
The immediate vicinity of the nesting hole is defended by pink cockatoos against conspecifics as well as other birds. Ownership of a nesting cave is often indicated by the fact that one of the two partner birds is sitting quietly in the cave entrance. What is more noticeable is behavior in which one of the partner birds or even both partners sit upright on a branch, half spread their wings, spread their tail feathers and screeching screams . In the most extreme form of this most restrained form, this attitude is accompanied by bows. Not yet sexually mature cockatoos show a milder form of this behavior when they begin to inspect nesting holes towards the end of the breeding season.
The eucalyptus trees, in which pink cockatoos typically breed, usually have such spreading tops that other pink cockatoos can also stay in the trees that have an occupied nest. However, if a bird falls below a distance of three meters, the cave owners warn with loud calls. If the bird approaches further, one of the partner birds approaches the intruder in flight and threatens with a slightly opened beak. He then runs towards the bird, which then usually backs away on the branch and finally flies away. If he remains seated or if he continues to approach, the owner of the nest box will bite the approaching bird in the foot. In relatively rare cases, mutual biting occurs.
Clutches and nestlings
The clutch consists of two to six eggs on average. The eggs are elliptical in shape and measure 35 millimeters by 26.5 millimeters. When they lay eggs, they weigh an average of 13.7 grams. The laying interval is on average 2.66 days. Both parent birds breed. You usually start with the incubation after the fourth egg has been laid or with the laying of the last egg for small clutches. The nestlings hatch after a breeding period of 23 to 24 days. Their hatching is largely synchronized within 48 hours. During the first eight to ten days of their life, they are almost constantly huddled by the parent birds , the intensity of the huddling depending on the ambient temperature. This is usually highest in the afternoon hours and huddling is usually interrupted during this time. Between the tenth and the 21st day of life, pink cockatoos hover their nestlings only at night. When they reach the 21st day of life, the young birds are feathered to such an extent that the parent birds do not huddle.
The nestlings are fed soft, easy-to-digest seeds such as those of herons-beaked species for the first few days of life . In years when the rainfall is so low that such plants do not bloom and accordingly do not set any seeds, pink cockatoos find it difficult to find sufficient food for their nestlings. In principle, however, the number of clutches is significantly lower in such years, as the females do not build enough fat reserves to lay eggs.
Fledglings
Young pink cockatoos leave the nest when they are seven weeks old. Despite the largely synchronous hatching of the nestlings, in extreme cases there can be an interval of up to 12 days between the first and last young birds of a brood. Especially with large clutches, it is difficult for the nestlings to train their wings. Because of the mostly chimney-like shape of the nesting holes, usually only the nestling sitting at the entrance has the opportunity to spread its wings. On their first flight, the young birds are usually accompanied by the parent birds. The flight usually ends in the next group of trees. Fledglings that fly out later are led by the parent birds to the fledglings that have already flown out. The cohesion of the family association is essential because the young birds depend on their parent birds to be fed for another six to seven weeks.
Ian Rowley has observed in the wheat belt of Australia that certain groups of trees are preferred as meeting places for young birds. He calls these places "kindergartens". The young birds gathered there can often be seen flying in flocks around the group of trees, calling out loud. Presumably this is how they train their flying skills. However, they are at an increased risk of being hit by birds of prey. The gathering of relatively inexperienced pink cockatoos particularly targets peregrine falcons and wedge-tailed eagles .
When parent birds come to the groups of trees with food, they call out loud, whereupon their young birds break away from the flock and are then fed. Such kindergartens can exist for several weeks at individual locations. However, the individual young birds only stay for a relatively short time until all members of their family group are together. As soon as all the birds in a clutch have flown out, the parent birds lead to groups of trees that are closer to the feeding ground. Fledglings begin after about two to three weeks to join their parent birds while they are looking for food on the ground and two weeks later they begin to look for food on the ground themselves. Around the hundredth day of life, young birds are no longer fed by the parent birds. Compared to other cockatoo species, this means that pink cockatoos become independent very early on. They join other young birds and usually migrate downwind from the breeding area. These flocks of young birds nomadize in very large areas. The directions of migration are determined by the available food resources. From the age of two, the area in which the birds nomad becomes smaller and is then around 1000 square kilometers.
Mortality rate
The most extensive studies on the mortality rate of the pink cockatoo are from the southwest of Australia. Investigations there have shown that the clutch contained an average of 4.31 eggs. The hatching rate was 82.6 percent. However, an average of only 1.92 young birds grew per clutch. Out of 100 juveniles that left the nest box, 81 survived the first 100 days. Only 49 were older than half a year. Almost 20 reached the second year of life and only about nine birds reached the third year of life.
Of the dead pink cockatoos that were found and the cause of death could be determined, three quarters fell victim to being shot down by farmers. Seven percent were hit by domestic cats , seven percent grabbed by birds of prey and five percent killed in traffic. The mortality rate is so high that a pair of pink cockatoos has to breed successfully eight times on average to produce two young birds.
Systematics
Pink cockatoos have a skull bone structure that differs from the actual cockatoo . The dunes of the nestlings are also colored differently than in this species of cockatoo. They have therefore been listed as a separate genus within the cockatoo family for several decades.
Although the pink cockatoo is a common and well-studied species, descriptions of its subspecies and their respective ranges are so far only sparse. The extent to which the division into three subspecies is justified has therefore not yet been conclusively clarified.
| subspecies | Distribution area | Distinguishing features of the individual subspecies |
|---|---|---|
| Western pink cockatoo
( E. r. Roseicapilla ), nominate form |
The distribution area extends from the Pilbara region in Western Australia to the north to the foothills of the Great Sand Desert and even further north reaches Eighty Mile Beach . | The nominate form is the smallest subspecies. The spring bonnet is more whitish in color. |
| Eastern pink cockatoo
( E. r. Albiceps ) |
East and Southeast Australia | Compared to the nominate shape, the hood is shorter. The crown and back of the head are white with a pink feather base. The delimitation of this pink head plumage from the darker neck plumage is very sharp |
| Kuhl's pink cockatoo ( E. r. Kuhli ) | Northern Australia from the Kimberley Division in Western Australia to the south of the Cape York Peninsula. | The plumage is overall lighter than that of the nominate form. The spring bonnet is a little more pink. The bare eye ring is strikingly deep pink. |
Pink cockatoos and humans
Pink Cockatoos as a pest
Pink cockatoos are considered a pest in much of Australia. As a species that takes up its food almost exclusively on the ground, pink cockatoos cause considerable damage when sowing grain because they eat the seeds that have been sown. Freshly sprouted grain is torn up and eaten by them and they peck the grains from the ears in both the semi-ripe and ripe state. Farmers occasionally complain of complete crop failures. By the end of the 1980s, pink cockatoos also caused considerable damage after the grain harvest. Pink cockatoos had specialized in opening the sides of the grain sacks that had been set up for removal in the early hours of the morning and eating the grain that trickled out. They also visited the open top grain silos on a regular basis. Damage was also caused by the soiling of the grain with excrement, so that the grain was often only approved for sale by the responsible authorities after extensive cleaning. Other post-harvest methods of storing grain have now reduced this damage. Pink cockatoos can also cause considerable damage to sunflower and sorghum fields. Australian farmers are therefore repeatedly demanding higher shooting rates for this cockatoo species.
Pink Cockatoos relatively often destroy telephone lines, which in Australia mostly run above ground. It is said that by gnawing the bark, they cause the trees to die, which they often visit as trees for sleeping and resting. However, more detailed studies have shown that this is not the case. The death of branches and trees is primarily a result of anthropogenic interventions in the original vegetation. However, they also cause considerable damage to lawns. Blue grasses , which are often used as lawns for sports fields in Australia, form rhizomes that are dug up by the pink cockatoos.
Because of the great agricultural damage caused by the pink cockatoos, Australian authorities commissioned studies on the behavioral ecology of pink cockatoos from 1969 to 1977. The reason was a targeted expansion of grain cultivation in southwest Australia, which led to an increase in the population of the following pink cockatoos and thus triggered considerable conflicts with farmers. The studies were carried out by the Australian ornithologist Ian Rowley , who continued his research on pink cockatoos after completing these studies and published a comprehensive study on these cockatoos in 1990. According to this study, pink cockatoos are among the four or five best-researched parrots in the world.
Ian Rowley came to the conclusion in his investigations that the damage to grain can be greatly reduced by appropriate cultivation and harvesting methods. The use of modern machines and the rapid removal of the grain in the wheat belt of Australia reduce the loss by pink cockatoos so drastically that, in his view, shooting is no longer justified. Above all, farmers should refrain from leaving plants with mature seed heads in the field for a few more weeks, as this significantly increases the risk that flocks of cockatoos will cause considerable damage.
attitude
Pink Cockatoos were first kept at London Zoo in 1843. In the decades that followed, these cockatoo species were regularly imported into Europe, which only ended after Australia issued an export ban on all of its fauna. Pink Cockatoos, which are kept in Europe today, usually come from offspring. The first offspring took place in Great Britain in 1876. The first German offspring took place in 1961. Today black cockatoos are bred in many European and North American countries. There is also extensive commercial breeding in South Africa. In Australia, most of the pink cockatoos kept are wild-caught. Hybrid breeding with other cockatoos is not uncommon. Pink cockatoos have already been successfully crossed with yellow-crested , Inca and bare-eyed cockatoos .
Pink cockatoos are demanding and long-lived fosterlings who are kept in spacious all-metal aviaries because of their need for movement and their tendency to gnaw. Keeping them individually is considered inappropriate and is prohibited in Germany and Austria. If kept improperly, pink cockatoos are prone to lethargy and obesity. Pink Cockatoos are compulsive eaters. Obesity is therefore considered to be a major cause of death in caged and aviary animals. It is often the result of inappropriate feeding with too fatty grains such as sunflower seeds. Since pink cockatoos often make use of their loud and high-pitched voices, which can be heard from far away, keeping free-vaults often leads to problems with neighbors.
supporting documents
literature
- Joseph M. Forshaw , illustrated by William T. Cooper: Australian Parrots. 1st German-language edition. Volume 1: Cockatoos and Lories. Arndt-Verlag, Bretten 2003, ISBN 978-3-9808245-1-4 .
- PJ Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Bird. Volume 4: Parrots to Dollarbird. Oxford University Press, Oxford 1999, ISBN 0-19-553071-3 .
- Dieter Hoppe : Cockatoos - way of life, keeping and breeding. Eugen Ulmer Verlag, Stuttgart 1986, ISBN 3-8001-7155-4 .
- Werner Lantermann: Parrot studies: biology - behavior - keeping - species selection of parakeets and parrots. Parey, Berlin 1999, ISBN 3-8263-3174-5 .
- Ian Rowley : The Galah - Behavioral Ecology of Galahs. Surrey Beatty & Sons in collaboration with The Commonwealth Scientific and Industrial Research Organization, Division of Wildlife and Ecology and the Royal Australasian Ornithologists Union, Chipping Norton 1990, ISBN 0-949324-27-2 .
Web links
- Horstkonrad Pöpping, Sven Pöpping: The pink cockatoo. Pöpping Breedingcenter GmbH, archived from the original on April 20, 2011 ; Retrieved December 11, 2013 .
- rosakakadu.com Pink Cockatoo homepage
- Plumage of the pink cockatoo
Individual evidence
- ↑ Hoppe, p. 117.
- ↑ Lantermann, p. 413.
- ↑ Hoppe, p. 113.
- ^ Forshaw, p. 150.
- ^ Rowley, p. 38.
- ^ Rowley, p. 4.
- ^ Rowley, pp. 136 and 137.
- ^ Forshaw, p. 150.
- ↑ Hoppe, p. 113.
- ^ Rowley, p. 35.
- ^ Forshaw, p. 151.
- ^ Rowley, p. 137.
- ^ Rowley, p. 32.
- ^ Rowley, p. 34.
- ^ Lantermann, p. 414.
- ^ Rowley, p. 34.
- ^ Forshaw, p. 160.
- ^ Rowley, p. 35.
- ^ Rowley, p. 35.
- ^ Forshaw, p. 160.
- ↑ Rowley, p. 34 and p. 35.
- ^ Rowley, p. 43.
- ↑ Rowley, p. 43 and p. 44.
- ^ Forshaw, p. 160.
- ^ Rowley, p. 46.
- ^ Rowley, p. 48.
- ↑ Rowley pp. 44-45.
- ^ Rowley, p. 4.
- ^ Lantermann, p. 414.
- ^ Forshaw, p. 154.
- ^ Forshaw, p. 154.
- ^ Forshaw, p. 153.
- ^ Forshaw, p. 159.
- ^ Forshaw, p. 138.
- ^ Rowley, p. 70.
- ^ Rowley, p. 70.
- ^ Rowley, p. 71.
- ^ Rowley, p. 36.
- ^ Rowley, p. 41.
- ^ Forshaw, p. 160.
- ^ Forshaw, p. 158.
- ^ Forshaw, p. 158.
- ^ Forshaw, p. 159.
- ^ Rowley, p. 69.
- ^ Rowley, p. 50 and p. 57.
- ^ Rowley, p. 57.
- ^ Rowley, p. 50.
- ↑ Hoppe, p. 115.
- ^ Forshaw, p. 161.
- ↑ Rowley, p. 20.
- ↑ Rowley, pp. 20 and 21.
- ↑ Hoppe, p. 115.
- ^ Rowley, p. 21.
- ^ Rowley, p. 26.
- ^ Forshaw, p. 160.
- ↑ Rowley, p. 27.
- ^ Rowley, p. 28.
- ↑ Rowley, p. 40.
- ^ Rowley, p. 57.
- ^ Rowley, p. 59.
- ^ Rowley, p. 60.
- ^ Lantermann, p. 415.
- ^ Forshaw, p. 162.
- ↑ Hoppe, p. 115.
- ^ Rowley, p. 62.
- ^ Rowley, p. 76.
- ^ Forshaw, p. 162.
- ^ Rowley, p. 75.
- ^ Forshaw, p. 162.
- ^ Rowley, p. 81.
- ^ Forshaw, p. 162.
- ↑ Hoppe, p. 115 and p. 116.
- ↑ Hoppe, p. 116.
- ^ Rowley, p. 83.
- ^ Rowley, p. 86.
- ↑ Rowley, p. 85, pp. 87-88.
- ↑ Rowley, pp. 54 and 55.
- ^ Rowley, p. 55.
- ^ Rowley, p. 56.
- ^ Rowley, p. 93.
- ^ Rowley, p. 107.
- ^ Rowley, p. 121.
- ^ Rowley, p. 122 and p. 123.
- ^ Rowley, p. 132.
- ^ Rowley, p. 133.
- ↑ Rowley, p. 134; In his words “ a day nursery for babies ”.
- ^ Forshaw, p. 163.
- ^ Rowley, p. 135.
- ^ Rowley, p. 135.
- ^ Rowley, p. 68.
- ^ Rowley, p. 135.
- ↑ Rowley, pp. 68 and 69.
- ↑ Lantermann, p. 98.
- ↑ Lantermann, p. 98.
- ↑ Lantermann p. 98.
- ↑ Hoppe, p. 113.
- ↑ Hoppe, p. 114.
- ^ Lantermann, p. 415.
- ^ Rowley, p. 2.
- ^ Rowley, p. 2.
- ↑ Lantermann, p. 417-
- ^ Rowley, p. 29.
- ↑ Lantermann, p. 97.
- ↑ Lantermann, p. 97.
- ^ Forshaw, p. 157.
- ↑ Lantermann, p. 417.
- ↑ Lantermann, p. 476.
- ↑ Lantermann, p. 476.
- ↑ Hoppe, p. 117.
- ^ Forshaw, p. 164.
- ↑ Hoppe, p. 118.