Found in most parts of the world, the House Sparrow (Passer domesticus) is the most widely distributed wild bird and has a conservation status of ‘least concern’ on the IUCN Red List of Threatened Species. However, in recent years conservationists in some parts of the world, including the United Kingdom and India, have been drawing attention to the fact that the numbers of these cheerful little birds have been dwindling, with no clear indication as to why this is the case. In order to alert the public to the plight of the Sparrow, as well as to enlist public support and participation in counteracting this trend, conservationists in London and India have joined forces to create World Sparrow Day, taking place on March 30, 2013.
Under the banner of “Rise for the Sparrow: Experience the Power of One”, World Sparrow Day is calling on citizens, educational institutions and corporate companies to do their bit for conservation and raising awareness. Individual citizens, wherever they may be, can assist by providing a regular source of food and water, eliminating poisons from their gardens and gardening organically, planting more bird friendly plants including hedges, and even putting up nest boxes for House Sparrows. Another suggestion from the organizers of World Sparrow Day is to take some grain along on outings and picnics, set it out near a thicket and wait to see if sparrows and other ground-feeding birds appear. This is a great way to teach children about the importance of birds in our environment.
Known for their life-long loyalty to their chosen mate, House Sparrows are gregarious little birds, often roosting communally with nests overlapping one another in clumps. They may regularly be seen dust-bathing or bathing in water together and they frequently join together in song. While some birds may migrate in regions with harsh winters, the majority of House Sparrows seldom fly more than a few kilometers from where they were raised. As their name would suggest, they are comfortable around humans and are often the first birds children become acquainted with. They are also very resourceful in obtaining their preferred food of seeds and grains, and are known to peck open bags of feed in warehouses and supermarkets. For this reason, some may consider them to be pests, but in general they are a welcome sight, particularly in the suburbs as they help clear gardens of aphids, snails and a variety of destructive insects. So you may want to consider getting involved with World Sparrow Day to ensure these cute little birds are still around for our children’s children.
Many bird species have amazing ways of adapting to changes in their environment, and a recent study in Britain has revealed that great tits, blue tits and other native species are tapping into a new food source as a counteractive measure against the effects of climate change. Some bird species have started laying their eggs too early in the year, most likely as a result of climate change, and this has resulted in their chicks hatching out before their food source is available, the food source being caterpillars that feed on newly sprouting oak leaves in spring. The new food source is the protein-rich larvae of invasive oak marble gall wasps which the birds access by pecking away the tips of the galls found on the oak trees. Researchers working on the project, Professor Graham Stone of the University of Edinburgh, and Dr Karsten Schönrogge of the Center for Ecology and Hydrology, noted that the evidence shows that the gall wasp larvae are not just an ‘occasional snack’, but rather a ‘really significant food source’.
The oak marble gall wasp (Andricus kollari) lays its eggs within the oak tree leaf buds via its ovipositor. This then develops into a round mass of green plant tissue which later turns brown and becomes hardened. Within this hardened gall there is a single wasp larva, and this is what the bird is after. These galls are found in their thousands on the Turkey oak trees (Quercus cerris) which were introduced into Britain in 1735. The first wasps that emerge are all female and go on to lay their eggs in the same manner, but without mating. The galls grow over winter and in early spring both males and females hatch, go on to mate, and the cycle starts again.
Credit goes to Dr Tracey Begg who had the task of cutting open more than 30,000 Turkey oak buds collected from eight sites in Scotland and England. Of the 3,000 galls she examined, Dr Begg found that on some trees up to half had been pecked open, leaving ragged marks, as opposed to the smooth hole wasps create when they emerge naturally, confirming that the birds are using the wasp larvae as a major food source.