Cuckoos (or cuckoos) form a family of birds belonging to the cuckoo order. The common cuckoo is the most famous member of this family.
Different types of cuckoos have different sizes. In most species belonging to the cuckoo family, the mass barely reaches one hundred grams, and the body length does not exceed forty centimeters.
However, all members of this family are characterized by the presence of a long tail, a slender body and strong legs. Plumage, as a rule, does not have a bright color, sexual dimorphism in color is poorly developed or absent altogether.
Many cuckoos are nest parasites, that is, they throw their eggs into other people's nests (typical of polygamous species). Chicks of all kinds of cuckoos are born helpless - they are blind and naked. Outwardly, the chicks of cuckoos are similar to the chicks of their "adoptive parents". Cuckoos develop quickly, they can leave the nest in a couple of weeks after birth.
Cuckoos inhabit forests, but some individuals prefer open areas. A significant number of species feed mainly on insects. The number of species in the family reaches one hundred and forty, all of them are combined into six subfamilies: real cuckoos, clawed cuckoos, Madagascar cuckoos, running cuckoos, larvae cuckoos and speckled cuckoos.
The cuckoo family includes species - American cuckoo, clawed cuckoo, plantain cuckoo. Their representatives equip their nests in bushes or trees, and even small vertebrates, such as lizards, are included in the diet of these tropical cuckoos.
The life span of cuckoos in natural conditions for them ranges from five to ten years.
Cuckoos throw their eggs into the nests of other birds. This is the case with many species of cuckoo that are nest parasites. Cuckoo chicks tend to develop much faster than chicks of other birds. In this regard, the "foundling", soon after birth, will be able to displace the chicks of the bird in whose nest he found himself. For the same species of cuckoos that are monogamous, pair formation is characteristic during the breeding season, which subsequently build nests, incubate eggs and feed the newly born chicks.
The common cuckoo is a medium-sized bird. The body length of the common cuckoo reaches forty centimeters, and the wing length is about twenty two centimeters (the wingspan is sixty centimeters). Individuals of this species have long flight wings and a long stepped tail (its length reaches eighteen centimeters). The common cuckoo outwardly (in size and color) is similar to the sparrowhawk.
Sexual dimorphism is not pronounced in common cuckoos. On the contrary, it is very pronounced. In color, adult females differ significantly from adult males. The plumage of adult males is dark gray on the tail and back and light gray on the chest, goiter and throat. As for the rest of the plumage, it is white with pronounced dark transverse stripes. As for the females, their plumage color on top has either rusty-red or brownish shades. Juveniles have either reddish or grayish plumage, regardless of gender. In size, the female is slightly different from the male, the body weight of adults varies from one hundred to one hundred and twenty grams.
The common cuckoo has a wide distribution area. The nesting places of the common cuckoo include European territories, Asia, Africa. The common cuckoo can be found even in the Arctic Circle. But the territories of the southern half of Indochina, as well as the Hindustan and Arabian peninsulas are not a nesting place for the common cuckoo. The common cuckoo, laying eggs in the nests of passerine birds, can be seen in the forest-steppe and steppe, in forests and taiga, near water bodies, in parks and gardens, on the outskirts of deserts and high in the mountains.
The common cuckoo is a migratory bird. This is indeed the case over a significant part of the distribution area. The common cuckoo hibernates in southern and tropical Africa. Much less often, individuals of this species fly away to winter in the southern provinces of China, Indochina, Ceylon, India and the southern regions of the Arabian Peninsula. As for individuals nesting directly in southern and tropical Africa, they are characterized by a sedentary lifestyle. An interesting fact is that with the onset of spring, cuckoos immediately leave their wintering grounds, for example, those individuals that nest in European territories fly out of Africa right in early March. However, these birds get to their nesting sites very slowly (during one day the cuckoo flies about eighty kilometers), the first cuckoos arrive in the central regions of Europe only in the last April days. The northern boundaries of the distribution area of the cuckoo reach only with the end of spring.
On the territory of the Russian Federation, the cuckoo can be found everywhere. This is practically the case when it comes to the period from May to July. Cuckoos cannot be seen except in the northern tundra. Interestingly, in the European part of the country you can see representatives of only one species from the cuckoo family - the common cuckoo, in the central part of Russia - two species, but in the eastern part of the country there are 5 parasitic species of cuckoos. Cuckoos found on the territory of the Russian Federation prefer to settle in forests and parks. Especially favorite places for them are coastal thickets, bushes, meadows and edges along the clearings.
Polygyny is a common occurrence in the mating relationship of common cuckoos. Polygyny in this case is manifested in the following. The male attracts females with his cries, having previously occupied a large area. He makes sounds "cuckoo", this happens many times, and the sounds differ in their volume. By the way, the cuckoo got its name thanks to this feature. As for females, they are much more silent than males. The voice of females can be heard during their flight, but this is not a loud "kuk-ku", but a gurgling trill of kli-kli-kli. Its purpose is to attract males. The male of the common cuckoo tries to fly around all his possessions in one day. Flying around the territory, the male alternately mates with females. It is interesting that each of them is located in a certain area of the terrain. The area of such a site ranges from two to four hectares. On the territory of her plot, the female chooses future "educators" of her offspring from birds of other species, because nest parasitism is characteristic of the common cuckoo. In summer, she does not incubate eggs, and does not build nests for herself. An interesting fact is that science has recorded cases of cuckoo throwing eggs into the nests of more than one hundred and twenty species of birds. Surprisingly, the female descendants of one common cuckoo, as a rule, remember the area where they were fed, and the appearance of those birds who took part in this. With the onset of a new summer, they return to these lands.
The female of the common cuckoo is distinguished by special observation. This is required by the specificity of behavior. The female is not only observant, but also secretive. She monitors the adoptive parents chosen for her future chick with extraordinary care. The female is interested in building a nest, laying eggs. Amazingly, the cuckoo tries to put its egg in a nest with eggs of the same size and color. She kind of reproduces a copy of them. Having improved the moment (during intensive egg-laying), the female takes out one egg from the master's nest and lays her own egg instead (it is outwardly identical to the others). The duration of this procedure does not exceed ten seconds. The fate of the stolen egg is either to be thrown out somewhere or to be eaten by a cuckoo. During one summer, the female is able to produce from thirteen to twenty eggs. She can toss, one in each nest, only from two to five eggs, and by determining the right moment in time, the female of the common cuckoo is capable of holding an egg in the oviduct, already ready for demolition, for three days. Nesting parasitism had such an impact on the physiology of individuals that only when the female discovers a new nest under construction of future adoptive parents does the next egg begin to form.
The substitution of a master's egg for a cuckoo egg can be easily detected. This is not true. This is extremely rare. The development of embryos in cuckoo eggs takes about twelve to thirteen days, which is much faster than the development of embryos in the host's eggs. Cuckoo chicks that have been born are often outwardly similar (and not only externally, but, for example, also in voice) to the rest of the chicks in the nest. Arched back, a cuckoo chick can easily throw newborn chicks or eggs out of the nest. Moreover, he constantly demands to eat and, accordingly, grows rapidly (already on the twenties - twenty-second days the cuckoo leaves the nest, its size is almost three times larger than the size of the parents). For two to three weeks, the parents roam with the cuckoo in forest plantations and parks. The radius of such movements is two to three kilometers from the nest.
The cuckoo wreaks havoc on the environment by ruining nests. However, there is also benefit from it. The cuckoo destroys a variety of insects that are harmful to the forest. These are, for example, pine silkworms and furry oak caterpillars. These insects are not eaten by small songbirds. The reason lies in their digestive system. These insect pests are included in the diet of the common cuckoo.
The deaf cuckoo looks like an ordinary cuckoo. Is that the size is slightly smaller. The common cuckoo and the deaf cuckoo are the closest relatives. The body length of a male deaf cuckoo reaches thirty-five centimeters. The deaf cuckoo leads mainly a migratory lifestyle, lives mainly in coniferous forests, but you can also see it in groves. It feeds on plant seeds and small insects.
The Indian cuckoo is a common bird in Primorye. Even in the second half of the twentieth century, this was so. Nowadays, it is rather rare here. The distribution area of the Indian cuckoo on the territory of the Russian Federation covers deciduous forests of the Amur region. The Indian cuckoo is wintering in Southeast Asia. Interestingly, the Indian cuckoo also has a similar appearance to the common cuckoo. A distinctive feature is the bicolor beak and the presence of a wide black pre-apical stripe.
The Indian cuckoo is cautious. This is a very secretive bird, which makes it very difficult to observe it. This circumstance was the reason that researchers for a long period of time had a meager amount of knowledge about this bird. Even in the middle of the twentieth century, the eggs of the Indian cuckoo found in the nests of the Siberian shrike were mistaken for the eggs of the common cuckoo. As for the Siberian shrike, nowadays it is the only species-educator known on the territory of the Russian Federation. A clutch of Siberian shrike eggs contains from five to eight eggs, to which another Indian cuckoo egg is often added. Outwardly, it is similar to the rest of the eggs in the nest, it is slightly larger.
Little cuckoo is small in size. Indeed, its weight barely reaches sixty grams. By weight, the small cuckoo is inferior even to the starling, but it wins, in comparison with it, in size - largely due to the elongated tail and long flight feathers.
The lesser cuckoo is similar to the deaf cuckoo. They are united by the color of the plumage, as well as the common species-educators. The latter include warblers. Particularly interesting is the little cuckoo and its educator species in the vicinity of the village of Khasan (the little cuckoo lives in South Primorye, and winters in Southeast Asia). The teacher is a short-winged warbler, which is in many ways original. Surprising at least is the fact that the female of the short-winged warbler is almost half the size of the male. Polygyny is characteristic of both the short-winged warbler and the lesser cuckoo. The short-winged warbler builds rather large nests that have a lateral exit. In one season, the female of the small cuckoo throws one (or two) eggs into such nests, from which a chick appears on the twelfth day. The cuckoo does not waste time and soon remains alone in the nest - it simply throws out the chicks that have already been born or the eggs in it from the nest. After about two weeks, the cuckoo flies out of the nest.
The broad-winged cuckoo has an extensive distribution area. We are talking about the distribution area of individuals of this species in the Far East of the Russian Federation. The broad-winged cuckoo can be found in the south of the Khabarovsk Territory and Primorye. However, despite this circumstance, ornithologists have much less information on the breeding biology of the broad-winged cuckoo, compared to other species belonging to the cuckoo family and found in Russia. Yuri Pukinsky (a researcher of Primorye, a famous ornithologist), for example, called the wide-winged cuckoo a mystery bird, because it is extremely difficult to track down this bird or find its eggs. But the voice of the wide-winged cuckoo is heard throughout the taiga. The male's voice resembles a buzz, which is prolonged in time and increases in volume and tone. The female's voice resembles that of a male, differs in tone (lower) and duration (short).
For the broad-winged cuckoo, the blue nightingale is the main parenting species. This circumstance makes it very difficult to find and study the eggs of the broad-snouted cuckoo. The fact is that the nests of the blue nightingale are on the ground. It is extremely difficult for a person to find them in the taiga wilderness. For the first time, the egg of the broad-winged cuckoo was lucky to see only in 1970, but even then it was mistaken for the egg of the ubiquitous common cuckoo. It was discovered by ornithologist Yuri Shibnev in the nest of a blue flycatcher. A week later, from the observed (larger than all the others) eggs, the cuckoo itself was born. The blue flycatcher is another breeding species of this cuckoo.
The egg of the wide-winged cuckoo is large. This is true. It exceeds the size of eggs of all other representatives of the cuckoo family inhabiting the territory of the Russian Federation. As for the color of the shell, it is similar to the color of the eggs of the parent species of the wide-winged cuckoo - the blue nightingale. The color of the shell is light blue-green. With the shells of eggs of another species-educator - the blue flycatcher - brownish specks are related to the eggs of the cuckoo. However, in this case, the egg of the broad-winged cuckoo differs markedly from the host's eggs. Although this does not prevent the blue flycatcher from carefully hatching an unusual egg and feeding the wrong chick. The eggs of the broad-winged cuckoo are oval-ellipsoidal.
The crested cuckoo is a beautiful bird. Its appearance is somewhat similar to that of a magpie.The gray-steel color is characteristic of the uppertail and head of the crested cuckoo, the brownish-gray color of the dorsal side of the body is decorated with white spots on the wings and shoulders. Sexual dimorphism in color is very poorly developed. A distinctive feature of the male is the presence of a crest on his head, which is large enough. The female also has a crest, but it is almost invisible. The body length of the crested cuckoo is approximately forty centimeters, the wing is twenty centimeters. The weight of individuals ranges from one hundred thirty to one hundred and forty grams. During the summer, the female lays from twelve to fifteen eggs, which are quite large. Each egg weighs about twelve grams, and this is when the female itself weighs one hundred and thirty grams. Eggs are thrown mainly into the nests of ravens. As a rule, two to four eggs are laid in one nest, which are very similar in size and color to the eggs of ravens. The diet of the crested cuckoo consists mainly of large insects and their larvae.
The crested cuckoo is a migratory bird. Depending on where the representatives of this species live. The distribution area of the crested cuckoo covers the territories of North-West, South and tropical Africa, Western Asia, Greece, France and the Iberian Peninsula. Only individuals living in South Africa are sedentary. Tropical and South Africa has become a wintering place for the crested cuckoo.