There are many species of house sparrows, these birds were most common birds in the world but today these little birds are no more ubiquitous. Common Indian house sparrow is Passer domesticus. It is a small brown bird of about 21 cm in length and 25-45 g by weight. It IUCN (International Union for Conservation of Nature) red list status is least concern but that’s due to not so bad condition in villages and forest.
They are vanishing like other species of birds from our cities and confined only to villages. These birds are natural indicator of ecosystem health. They are distributed worldwide and are evolved with humans. These birds are non-migratory so they can be used as an indicator species for study of pollution and other factors and their impact on our ecosystem. What had happened that now these little birds are out of our site? Their disappearance must be due to our drastically changing lifestyle and deteriorating ecosystem.
Biodiversity is very low in cities and town as compare to villages. Not more than 3-4 species of birds could be seen in our cities. Only Pigeons, crows and maina can be seen, some times we can notices the sound of kuku bird. Not only Sparrow but also parrots, woodpecker, kingfisher and bulbul, etc., are also out of our site. These birds were common in our childhood but our kids are not much fortunate to see them. I remember every year one pair of sparrow use to come to our home and they make their nest, after laying eggs and caring them till their first flight we see all their activities. My grand mother was giving water and food to them. We were keeping fans switched off if they enter the room. All kids take care of the birds and protect them from cats. Days fly and so do the sparrows.
These birds co-evolved with human beings and feed on seeds and food left over by human. They make their nests in human houses and take dust bath in muddy garden. Now due to urbanization and modern way of living, we have glass-covered windows, cemented gardens so no scope for sparrows to live with us. 12% of India’s birds are facing extinct while 12 species of birds in India are critically endangered according to “The Bird Life International” and IUCN (1).
Recently, World House Sparrow Day was announced and celeberating every year on March 20 from 2010. This day originated due to coservational work done by “Mohammed Dilawar” and his organisation for bird coservation, “The Nature Forever Society”. There are 35 bird protected areas out of approx 500 reserves for other animals and plants. 12 % of birds are going to extinct while 12 species of birds in India are critically endangered. Primariliy seed eaters but in breading season they eat worms (Lowther and Cink 1992). In August 2012 Sparrow became the State bird of Delhi, India. It is the state bird of Bihar (State in India) too. More over Eurasian Tree Sparrow (Passer montanus) is the national bird of China. The Italian Sparrow (Passer italiae) is the national bird of Italy.
Sparrows are integral part of immediate human surroundings. Loss of birds increases the number of harmful insects like mosquitoes which were vectors of numerous pathogens.We never imagined that these birds would disappear so quickly form our ecosystem. We have sorrow for sparrow, but the reason for its disappearance is not one. In this article I would like to find out the causes of sparrows reducing population and how can we help little birdies to reappear.
Reasons for disappearance of sparrow: Sparrows are highly sensitive to local environmental parameters, which also have contributions in its decline. There are multiple reasons out of which the newly introduced mobile towers and electromagnetic waves in the atmosphere appear to be a major reason. Some of the other possible causes of decline in sparrow’s population are summarised below.
- Change in building construction pattern with glassed windows. Actually stop the entry of these little birds.
- Well maintained modern gardens in houses instead of weedy gardens which provide feeding grounds for sparrows.
- Electromagnetic waves from cell phone towers are the major drivers of decline of this bird. The electromagnetic radiation is proved to affect reproduction, circulatory and central nervous systems and may cause microwave syndrome which leads to decline in general health (Kamath et al., 2014). The criss cross electric cables also do harm to them.
- Use of unleaded petrol may also be the cause of the disappearance of sparrows because two chemical compounds replaced lead, which are very hazardous. The introduced chemical compounds are: MTBE (methyl tertiary butyl ether) and benzene. Both are carcinogenic to animals. about unleade petrol and the connection with sparrow disappearence was first put forwared by Dr. Summers Smith in his books and papers.
- Change in agriculture patterns and increased use of pesticides results in a decline in invertebrate pray. Use of chemically treated seeds on which sparrow feed is one of the reasons for their decline.
- Air pollution, coupled with a diet lacking in antioxidants such as carotenoids, vitamins and minerals. Past studies demonstrated that rural or suburban populations of other species, like blackbirds, showed higher concentrations of vitamin E and carotenoids than their urban counterparts, hemoglobin level was also found low in urban population (4). Poor diet and pollution both affect the health of sparrow also it’s eggs. Urban environment is not good for these birds especially in breeding season, it also affect their future fitness as well.
- Competition with other species of birds and animals like crows, pigeon, dogs and cats, etc. and interaction with other animals which are vector of diseases can also be the reason of their death due to diseases. Sparrow may also be the part of diseases transfer.
- The case of the Disappearing House Sparrow (Passer domesticus indicus) Anjan Dandapat*, Dipak Banerjee and Dibyendu Chakraborty.
- Biology of the Ubiquitous House Sparrow: From Genes to Populations-By Ted R. Anderson.
- The Old World Sparrows (Genus Passer) Phylogeography and Their Relative Abundance of Nuclear mtDNA Pseudogenes by- Luis M. Allende, Isabel Rubio, Valentin Ruíz-del-Valle, Jesus Guillén, Jorge Martínez-Laso, Ernesto Lowy, Pilar Varela, Jorge Zamora, Antonio Arnaiz-Villena.
- Oxidative stress of House Sparrow as bioindicator of urban pollution by- AmparoHerrera-DueñasaJavierPinedaaMaría TeresaAntoniobJosé I.Aguirrea.
- Lead-free petrol may be villain in mystery of demise of the world’s most familiar bird by- Michael McCarthy @mjpmccarthy.