SRF, IDP Cell, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, India
*Corresponding author: Manpreet Kaur, SRF, IDP Cell, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, India
Submission: March 23, 2021;Published: May 04, 2021
Volume1 Issue3 May, 2021
The most common bird, seen feeding, roosting, and nesting near human settlements, especially in villages, has become a rare sight in rural areas of Punjab, India now. A few years ago, some alarm bells rang when the population of common house sparrows declined in India and other parts of the World. This Article highlights the apparent causes of the House Crow population decline in recent years. The bird population is especially susceptible to the impacts of anthropogenic activities on the environment, so there is an urgent necessity to maintain ecosystem balance in order to save these common birds from extinction.
Indian House Crow (Corvus splendens) is a common bird of the crow family that is native to an extensive area of India, nearby parts of Asia, and the Middle East. It has a well-documented history as an invasive pest overseas, with extensive naturalized populations in Iran, Sri Lanka, Pakistan, and Burma, self-introduced to East Africa, Indian Ocean islands, Malaysia, and South Africa, and elsewhere. Indian House crows mainly travel on ships and ship assistance is the most likely pathway to introduce these birds to most parts of the world. These introductions were successful because of their strong nexus with human settlements. However, currently, I have seen a very large decline in the House Crow population in villages of Sangrur district and Bathinda district and heard a similar story from people from other districts of Punjab. Lack of research and understanding has worsened the rate of their disappearance. As birds act as biological indicator of the environment, they need to be saved before they become endangered like Vultures and Sparrows in Punjab, India.
Corvus splendens (C. splendens) is a widespread resident in India, Nepal and Bangladesh, and has a grey neck collar. The five subspecies of Corvus splendens are: C. splendens splendens, C. splendens zugmayeri, C. splendens protegatus, C. splendens maledivicus and C. splendens insolens . The subspecies C. splendens splendens, C. splendens zugmayeri are found in the southern Jammu and Kashmir, Punjab and western Rajasthan. C. splendens zugmayeri is also found in the dry parts of South Asia and Iran and it has a very pale neck collar. The subspecies C. splendens protegatus is found in coastal areas, Kerala, the Maldives, and Sri Lanka, and nearby islets. C. splendens maledivicus is found in the Maldives. The darkest form is the C. splendens insolens found in Myanmar and lacks the grey collar .
House crows are predominantly black; medium-sized birds (42-44cm long (body and tail) and weigh 250-350g) with tails shorter than the wings and graduated or rounded at the back. Their plumage is rich black and glossy on the forehead, crown, throat, and upper breast, except for the nape, sides of the head, upper back, and breast, which are a lighter grey in colour. The Bill, tail, and legs are also black. The bill is stout with stiff and straight bristles that reach almost to the middle. The males and females are almost similar, but the males are slightly larger than the females . All its names, the generic name, the English ‘crow’, the Sanskrit ‘kaka’, the Hindi ‘kawwa’, the Kannada ‘kaaga’ are derived from its characteristic calls, which is short, repeated harsh ‘caw caw caw’ or a nasal ‘kaankaan’ .
The House crow is the primary consumer and omnivorous in nature, feed largely on insects, small vertebrates, bird’s eggs, fledglings (birds, mammals, reptiles), seeds especially corn, fruits, and garbage . Crow is extremely skilled in feeding; they feed on everything and anything that is edible whether alive or dead, that is why they are often considered as opportunistic and inventive feeders. They also feed on carrion . They spend much time searching for food on the ground but occasionally feed in trees.
This species shows great ecological flexibility and an obligate association with human presence, to the extent that no populations are known to live independently of humans . In India, the crows are consequently found in all villages, towns, and cities, except in forests and high-altitude areas. This species is known to undertake altitudinal and seasonal local movements in colder northern areas of the country during winter. In most (if not all) locations, Indian house crow abundance is closely associated with human population size, due simply to the expanding amount of rubbish generated.
House Crows are highly vocal, gregarious birds, generally unafraid of humans. They are very aggressive, will attack and chase off any large bird of prey. It is uncannily and ceaselessly vigilant, day or night and is the first to detect intrusions and raise alarm. Breeding pairs repeatedly dive-bomb people and other predators, which approach too close to their nests.
House Crow population has undergone a drastic decline in the last 10-12 years. House Crow and their habitats were virtually underneath noticing both ornithologists and academics, so few genuine investigations of the species were made, and the outcome is a continuing scarcity of hard data on the population ecology of this species.
Economic importance for humans: negative
Due to its preference for human settlements, the House Crow is considered a nuisance species, a competitor of native birds, and an agricultural pest. Large aggregations around buildings produce annoying noise. It is assumed that paramyxo viruses, for example, PMV 1 that causes Newcastle disease may be spread by House Crow. This is because; outbreaks of Newcastle disease in India were many times preceded by mortality in crows .
Economic importance for humans: positive
House crow is well named “Scavenger Bird” around the globe, they dispose considerable amount of unwanted garbage waste at damping sites. They were deliberately introduced into other countries mainly to aid in cleaning the environments especially the garbage . They are important organisms in the food chain. They are also very much necessary for our urban ecosystems as they clean the garbage which we dump in our streets. Crows like other bird also eats some plant fruit with seeds (e.g., Azadirachta indica, Carica papaya, and Lycopersi conesculentum), therefore, helps in plant propagation by defecating viable seed contents. Crows are also seen removing ticks from cows and donkeys but occasionally on goats and sheep, so helps livestock keepers tending operation (livestock health).
Possible reasons for decline
A decline in Houses Crow population is reported from different parts of India [10,11], but no such report is available from Punjab. Although, causes for the decline of Crow are not scientifically proved, as per my interpretation as an ornithologist, reasons for their decline are given under:
1. As we know in many areas, the birds feed almost entirely on refuse. So, it would not be wrong to speculate that their numbers may have seen declines or will decline in the future, basically with an increase in sanitation (waste thrown into dustbins or in plastic covers, making it inaccessible for crows).
2. Destruction of natural habitat (cutting of trees) reduced safe nesting and roosting places for Crows.
3. And lastly increased use of pesticides in agricultural areas of Punjab, could be the one reason as it results in a decline in invertebrate prey and health of birds.
© 2021 Manpreet Kaur. This is an open access article distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and build upon your work non-commercially.