The impact of Silver Gulls is quite profound, Tasmania has recorded a record number of Silver Gulls - seagulls, with an increase of 170% of the Pacific Gull. The most common gull in Australia is the Silver Gull. There are about 48 species of gull in the world, with three resident species in Australia (Silver, Pacific and Kelp Gulls). Often once found in tips, and rubbish refuges they are now found in most parks, buildings, fields, grasslands, lakes, sewer works and rooftops. A regular scavenger and ready to pester for scraps. They do have a very important place in the ecological system in that they are walking garbage bins, picking up any food dropped, insects, worms and small rodents.
It is the regurgitation of this food that blocks pipes, gutters and rooftops. The droppings foul streetscapes, damage paintwork to cars and foul areas of the roof (will strip the paint off) and buildings.
Behaviour
Silver Gulls nest, roost and feed in large groups. They can commute up to 40km from their roost or breeding colony to their feeding sites. They aggressively defend food and nesting territories. Gulls are habitual so if you have gulls nesting this year, they will back to nest next year. You can also expect twice the number as this year's young will return also, it's imperative you have a gull management plan in place before they start nesting.
Breeding
Silver Gulls usually breed on offshore islands, headlands, breakwaters, and/or causeways between August and February. Sometimes they nest on flat roof buildings and can prolong their breeding season for up to 11 months where food supplies allow. 1-3 eggs are laid in a nest made of anything from rocks or seaweed to stems from nearby plants. Two broods are raised per year with greater access to food areas has been able to increase its presence in populated areas with offshore breeding areas are overrun with inhabitants fighting for space. Silver Gulls live for 30 years and can reproduce for up to eleven seasons.
The largest Silver Gull breeding colonies in the world containing 40,000 to 50,000 pairs are located on islands in Port Phillip Bay, Melbourne and off Port Kembla, NSW.
Bird Strike
Between 1991 and 2001 there were 136 bird strikes reported to ATSB which involved gulls. Of these: 15.4% resulted in damage to aircraft 3.7% had an effect on planned flight 31% involved more than one bird. Although they are only medium-small birds, Silver Gulls present a serious risk to aircraft as they form large, dense flocks which can fly unpredictably. Frequently, more than one bird is struck which can potentially cause the failure of one or more engines.
Remember, that in order for AVIX to be most effective, timing for use must be well before nesting. It is against best practices to use equipment on nesting birds.