چَرخریسَکها پرندگانی هستند ریزجثه و ظریف به وزن تقریبی یازده گرم، درختزی، بالارو، شاد، زیبا و فوق العاده فعال و پرجنبوجوش است و صدای بسیار زیبایی دارد. بال هایش کوتاه و قلبش بزرگ و قوی است. از حشرات تغذیه می کند؛ طعمه را میان پنجه های پا گرفته، با فشار آوردن روی شاخه له کرده و می خورد. در میان پرندگان نغمه خوان از همه پرانرژی تر و در مقابل گرسنگی از همه کم طاقت تر است، بطوریکه بیش از ۲۴ ساعت نمیتواند گرسنه بماند؛ از این رو تلفات این پرنده در فصل زمستان قابل ملاحظه است.
در سوراخ تنه درخت آشیانه می سازد. اگر حفره درختی پیدا نکند، در سوراخ زمین، جعبه پست منازل و حتی در قوطی کنسرو خالی هم تخم می گذارد. در سال دو بار و در هر دفعه بین ۶ تا ۱۲ و گهگاه بیشتر تخمگذاری میکند. دهقانان گیلان آن را کولکاپیس یا یاکولکافیس را زاده بلبل می دانند و عقیده دارند بلبل ماده هفت عدد تخم می گذارد که از میان تخم ها تنها یکی بلبل و بقیه کولکاپیس به دنیا می آیند.
این پرنده از خانواده چرخریسکان(Paridae)است. چرخریسکها بجز آمریکای شمالی در جنگل ها، بیشه ها، پارک ها و باغ های تمامی نقاط دنیا یافت می شود.
These birds are called either "chickadees" (onomatopoeic, derived from their distinctive "chick-a dee dee dee" alarm call) or "titmice" in North America, and just "tits" in the rest of the English-speaking world. The name titmouse is recorded from the 14th century, composed of the Old English name for the bird, mase (Proto-Germanic *maison, German Meise) and tit, denoting something small. The spelling was influenced by mouse in the 16th century. Emigrants to New Zealand presumably identified some of the superficially similar birds of the genus Petroica of the family Petroicidae, the Australian robins, as members of the tit family, giving them the title tomtit although, in fact, they are not related.
These birds are mainly small stocky woodland species with short stout bills. Some have crests. They range in length from 10 to 22 centimetres. They are adaptable birds, with a mixed diet including seeds and insects. Many species will live around human habitation and come readily to bird feeders for nuts or seed, and learn to take other foods.
With the exception of the three monotypic genera Sylviparus, Melanochlora and Pseudopodoces, the tits are extremely similar in appearance, and have been described as "one of the most conservative avian families in terms of general morphology". The typical length of the family is between 10 to 16 cm (3.9–6.3 in) in length, when the monotypic genera are added this range is from 9 to 21 cm (3.5–8.3 in). In weight the family ranges from 5 to 49 g (0.18–1.73 oz), this contracts to 7 to 29 g (0.25–1.02 oz) when the three atypical genera are removed. The majority of the variation within the family comes in plumage, and particularly colour.
The bills of the tits are generally short, and vary between stout and fine dependent on diet. The more insectivorous species have finer bills, whereas those that consume more seeds have stouter bills. The most aberrant bill of the family is possessed by the Hume's ground tit, which is long and decurved.
Distribution and habitat
The tits are a widespread family of birds, occurring over most of Europe, Asia, North America and Africa. The genus Poecile occurs from Europe through Asia into North America, as far south as southern Mexico. American species in this genus are known as chickadees. Some species in this genus have quite large natural distributions, one, the grey-headed chickadee, is distributed from Scandinavia to Alaska and Canada. The majority of the tits in the genus Periparus are found in the south eastern portion of Asia. This includes two species endemic to the Philippines. The coal tit, also in this genus, is a much more widespread species, ranging from the British Isles and North Africa to Japan. The two crested tits of the genus Lophophanes have a disjunct distribution, with one species occurring in Europe and the other in central Asia.
The genus Baeolophus is endemic to America. The biggest genus, Parus has numerous species in Africa, several found in southern and eastern Asia, and one, the great tit, which ranges from Western Europe to Indonesia. Cyanistes has a European and Asian distribution (also nudging into northern Africa), and the three remaining genera, Pseudopodoces, Sylviparus and Melanochlora are all restricted to Asia.
Tits are active, noisy and social birds. They are territorial during the breeding season and often joining mixed-species feeding flocks during the non-breeding season. The tits are highly adaptable and, after the corvids (crows and jays) and parrots, amongst the most intelligent of all birds.
The tits make a variety of calls and songs. They are amongst the most vocal of all birds, calling continuously in most situations, so much so that they are only ever silent for specific reasons such as avoiding predators or when intruding on a rival's territory. Quiet contact calls are made while feeding to facilitate cohesion with others in their social group. Other calls are used for signalling alarm—a well known example being the "Chic-a-dee-dee" of North American species in the genus Poecile, the call which gives them their local common name, the chickadee. The call also serves a rallying call to summon others to mob and harass the predator. It has been demonstrated through experiments that the number of "dee" syllables at the end of the call increases with the level of danger the predator poses.
Diet and feeding
The tits are generalist insectivores that consume a wide range of small insects and other invertebrates, particularly small defoliating caterpillars. They also consume seeds and nuts, particularly in the winter. One characteristic method of foraging in the family is hanging, where they will inspect a branch or twig and leaves from all angles while hanging upside down to feed. In areas where numerous species of tit coexist different species will forage in different parts of the tree, their niche determined in no small way by their morphology; larger species forage on the ground, medium sized species foraging on larger branches and the smallest species on the ends of branches. Having obtained larger prey items or seeds tits will engage in hold-hammering, where they will hold the item with one foot and hammer it with the bill until it is open. In this fashion they can even open hazelnuts in around 20 minutes. A number of genera engage in food caching, hoarding supplies of food during the winter.
Tits are cavity-nesting birds, typically using trees, although Pseudopodoces builds a nest on the ground. Most tree-nesting tits excavate their nests, and clutch sizes are generally large for altricial birds, ranging from usually two eggs in the rufous-vented tit of the Himalayas to as many as ten to fourteen in the blue tit of Europe. In favourable conditions, this species had laid as many as nineteen eggs, which is the largest clutch of any altricial bird. Most tits are multibrooded, a necessary strategy to cope with either the harsh winters in which they reside in the Holarctic or the extremely erratic conditions of tropical Africa, where typically a single pair cannot find enough food to rear even one nestling and in drought years breeding is likely to be futile.
Many African tit species, along with Pseudopodoces, are cooperative breeders, and even pair-breeding parids are often highly social and maintain stable flocks throughout the non-breeding season.
Tits also have a variety of methods for attracting mates, primarily through their intricate, bouncing mating dance. Only the blue tit is typically polygynous: all other species are generally monogamous. Courtship feeding is typical of pair-breeding tits to deal with the cost of rearing their large broods.
Recently, the large Parus group has been gradually split into several genera (as indicated below), initially by North American ornithological authorities and later elsewhere. Whereas in the mid-1990s, only Pseudopodoces, Baeolophus, Melanochlora and Sylviparus were considered well-supported by the available data as distinct from Parus. Today, this arrangement is considered paraphyletic as indicated by mtDNA cytochrome b sequence analysis and Parus is best restricted to the Parus major—Parus fasciiventer clade, and even the latter species' closest relatives might be considered a distinct genus.
In the Sibley-Ahlquist taxonomy, the Paridae family is much enlarged to include related groups such as the penduline tits and long-tailed tits, but while the former are quite close to the titmice indeed and could conceivably be included in that family together with the stenostirid "warblers", the long-tailed tits are not. Indeed, the yellow-browed tit and the sultan tit are possibly more distant to the tits than the penduline tits are. If the two current families are lumped into the Paridae, the tits would be a subfamily Parinae.
Alternatively, all tits—save the two monotypic genera discussed in the preceding section and possibly Cyanistes, but including Hume's ground tit—could be lumped in Parus. In any case, four major clades of "typical" tits can be recognized: the dark-capped chickadees and their relatives (Poecile including Sittiparus), the long-crested Baeolophus and Lophophanes species, the usually tufted, white-cheeked Periparus (including Pardaliparus) with more subdued coloration and finally Parus sensu stricto (including Melaniparus and Macholophus). Still, the interrelationship of these as well as the relationships of many species within the clades are not well resolved at all; analysis of morphology and biogeography probably gives more a robust picture than the available molecular data.
Species in taxonomic order
These two monotypic genera are possibly less close to titmice than are the penduline tits: