THE CROW PART3 Dearfriends,
I amcontinuing more about the crow in this part of the posting. Most of theinformation are compilation from websites. I wish all members aHAPPY PONGAL Sincerely, Gopalakrishnan 13-1-2022. 17. Varietiesof crow. In thecrow family called “CORVIDAE” thereare about 40 varieties of crows. Some are very small, some medium and some very large.I have read from one of the mails of our member Mr. Srinivasan about the largesize of American crow. I have read from wikipedia in Australia crows are very small. The crowis a year round species. This means irrespective of season’s crows will be seenflying here and there. Crow is considered as one of the intelligent among living beings ( animals, birds etc). 18. Coloured crows. If we askany child the colour of the crow, answer would be BLACK. But there are crows with brown head in new Guinea, crows with white neck in Dominican republic. There isa variety called fish crowand another called Palmcrow. Fish crows are found in US Coasts, Palm crow is found in Cuba. In newGuinea there are also fully grey crows. White billed ( Tamil translaton- alaku)crows are available in Soloman islands. The crows generally available in Indiaare called house crow. As I toldearlier, we cannot domesticate the crow, but how it is called house crow then?Answer is given in next posting. 19 Blue crow-Azure jay The AzureJay or blue crow is a passeri form birdof the crow family Corvidae. It is found in the Atlantic Forest, especially with Araucariaangustifolia, in south-eastern Brazil far eastern Paraguay and farnorth-eastern Argentina. Itis the state bird of Paraná. It has atotal length of approximately 40 cm, and its plumage is intensely blue with acontrasting black head and upper chest. Males and females are similar, althoughthe females typically are smaller. It feedsextensively on the nut-like seeds but it is not strictly limited to this, sinceit also feeds on insects and fruits. As other corvids, Azure Jays are highlyintelligent. Their communication is complex, consisting of at least 14 distinctvocalizations. They form groups of 4 to 15 individuals that are well organizedin hierarchies. These groups remain stable for up to two generations. 20 Fossil records Theearliest corvid (crow family) fossils date to the mid-Miocene, about 17MILLION YEARS ago; Miocorvus and Miopica of France may be ancestral to crows 21 Morphology Corvids(Birds of crow family) are large to very large passerines with a robust build, stronglegs and all species except the Pinyon Jay have nostrils covered by bristle-likefeathers. Many corvids of temperate zones have mainlyblack or blue coloured plumage; however, some are pied blackand white, some have a blue-purple iridescence and many tropical species arebrightly coloured. Thesexes are very similar in color and size. Corvids have strong, stout bills andlarge wingspans. The family includes the largest members of the passerine order. The smallest corvid is the Dwarf Jay (Aphelocomanana), at 40 g and 21.5 cm. The largest corvids are the Common Raven (Corvus corax) and the Thick-billed Raven (Corvus crassirostris),both of which regularly exceed 1400 grams and 65 cm (26 inches). Speciescan be identified based on size, shape, and geography; however, some,especially theAustralian crows, are best identified by their raucous calls. 22.Ecology Corvids occur in most climaticzones. Most are sedentary and do not migrate significantly. However, during a shortage of food, eruptive migration can occur. Whenspecies are migratory, they will form large flocks in the fall (around August inthe northernhemisphere)and travel south. One reason for the success ofcrows, compared to ravens, is their ability to OVERLAP BREEDING TERRITORY. During breeding season, crowswere shown to overlap breeding territory six times as much as ravens. Thisinvasion of breeding ranges allowed a related increase in local populationdensity. 23 Food and feeding Corvidsare highly opportunistic foragers. The natural diet of many corvid species isomnivorous, consisting of invertebrates, nestlings, small mammals, berries, fruits, seeds, and carrion. However, some corvids,especially the crows, have adapted well to human conditions and have come torely on anthropogenic foods. Theincrease in available anthropogenic food sources is contributing to populationincrease in some corvid species. ome corvids are predators of other birds.During the wintering months, corvids typically form foraging flocks.However, some crows also eatmany agricultural pests including cutworms, wireworms, grasshoppers, andharmful weeds. Some corvids will eat carrion,and since they lack a specialized beak for tearing into flesh, they must wait until animalsare opened, whether by other predators or as roadkill. 24. Reproduction Respected members , there was a mail to me from amember that they do notunite in open- special to crow. Some more attributes are there intheir mating when I read. So I thought I must add them. Thepartner bond in corvids is extremely strong and even lifelong in some species. Thismonogamous lifestyle, however, can still contain extra-pair copulations. Males and females build largenests together in trees or on ledges. The male will also feed the female duringincubation. The nests are constructed of a mass of bulky twigs lined with grassand bark. Corvids can lay between 3 and10 eggs, typically ranging between 4 and 7. Theeggs are usually greenishin colour with brown blotches. Once hatched, the young remain in thenests for up to 6–10 weeks depending on the species. CORVIDS PROVIDE BIPARENTAL CARE. Mateselection is quite complex and accompanied with much social play in theCorvidae. Youngsters of social corvid species undergo a series of tests,including aerobatic feats, before being accepted as a mate by the opposite sex. 25.Social life Somecorvids have strong organization and community groups. Jackdaws, for example,have a strong social hierarchy, and are colonial during breeding. Providingmutual aid has also been recorded within many of the corvid species. Some corvids can be aggressive. Blue Jays, for example, are well known to attack anythingthat threatens their nest. Crows have been known to attack dogs, cats, ravens, and birds of prey.Most of the time these assaults take place as a distraction long enough toallow an opportunity for stealing food I will continue in nextposting. -- You received this message because you are subscribed to the Google Groups "Thatha_Patty" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. 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