Bird Deterrent Systems for Dams

Dams: A Refreshing Source of Life for Wildlife.

Dams are a refreshing source of life. Water reservoirs are designed to benefit agriculture, irrigation, and water consumption across the globe. At the same time, water structures attract a colorful mixture of wildlife. From dam fish and reptiles to birds and big mammals, dams can become a bubbling source of life for dragonflies, turtles, platypuses, ducks, and vegetation.

So why one needs to think over deterrent systems for dams?

Wild birds, in particular, are highly attracted by small dams as an opportunity to breed and find shelter during different migratory and seasonal changes. Interestingly, some of the most common species that dam owners in Australia can encounter are grassbirds, Australian reed warblers, and honeyeaters. That said, birds and other animals can introduce different plant seeds and diseases that can lead not only to poor water quality but fatal consequences for both livestock and people. That’s why one needs to consider bird deterrent system for dams.

Dams and Bird Deterrent Methods

When birds start colonizing a reservoir, private dam owners start facing numerous water management challenges. Therefore, regulating dam flora and fauna becomes essential to ensure high-quality water supply and guarantee both environmental and public health.

Here we should note that the increasing cases of avian influenza are one of the major concerns across Australia and the rest of the world. Waterfowl and shorebirds, in particular, can spread infections to commercial poultry that has no immunity to avian influenza viruses. Transmission can occur through direct contact or via contamination of grassed areas, water, and even clothing and machinery.

Both low pathogenic and high pathogenic avian influenza (e.g., H5N1) can lead to severe clinical symptoms, production losses, and substantial costs. It’s noteworthy that the first high pathogenic avian influenza outbreak was detected in Victoria in 1976. As viruses mutate quickly, in some parts of the world diseases can hop across species, including humans, which can be lethal. To be more precise, figures show that bird flu leads to fatal outcomes in more than 60% of infected people.

Bird Deterrent Systems for Dams

Given the deadly risks that many dam owners face, it’s no surprise that bird deterrent systems for dams are fundamental. Note that deterrent methods are defined as techniques used to exclude wildlife from specific areas. Though authorities discourage farmers from keeping waterfowl, we should agree that both big and small dams simply attract waterbirds and fish-eating birds.

Thus, proper water management based on long-term research and risk assessment strategies is essential to keep wild birds away from water reservoirs and farms. Interestingly, bird deterrent systems for dams can be grouped into different categories:

• Auditory deterrents: Auditory methods include various techniques, such as the use of gas cannons, pyrotechnics (e.g., pistols and rope fire-crackers), bio-acoustics (e.g., bird alarms that are highly effective against gulls and herons), ultrasonic and sonic devices.
  
• Visual deterrents: Visual methods also vary and often include the use of lasers (effective for cormorants), trained dogs, scarecrows, kites, balloons, flags, warning tapes, dyes, lights, floating solar-powered beacons, and mirrors. Additionally, radio-controlled aircraft, drones, boats, and other vehicles, as well as simulated predators (called effigies), can be used to scare wild birds away. Though not widely used across Australia, we should mention that falconry or the use of trained raptors can be beneficial around airports.
  
• Chemical deterrents: Chemical deterrents for dams are popular methods that can be also used for crop protection. Note that chemical methods can include both primary and secondary repellents. While primary repellents have repulsive smell and taste, secondary repellents can cause distress in birds. Secondary repellents in large doses, though, can become lethal to the birds.
  
• Physical deterrents: Physical deterrents are among the most popular deterrent methods. Nets, wires, floating Styrofoam blocks, weighted plastic balls, and other structures (e.g., anti-perching units) can all prevent birds from landing and nesting. Exclusion netting, for instance, is a beneficial technique, especially for orchards and vineyards; yet, exclusion netting can be costly ($23,000 and $72,000 per hectare) and difficult to install around dams and poultry farms. Note that regular maintenance is crucial to increase the effectiveness of any physical deterrent system.
  
• Habitat modifications: Habitat modification is another effective physical deterrent method used to stop birds from entering dams. Dam owners can lure birds back to their habitats (e.g., natural wetlands). At the same time, farmers can also plant long grass and shrubs to make their reservoirs less attractive. The use of sprays and vegetation covers is also beneficial, especially to protect fish from predators.
  
• Lethal methods: Perhaps one of the most undesirable methods to exclude birds from entering dams is the use of lethal practices, such as lethal shooting and egg destruction (e.g., oiling or replacing of eggs). Note that in Australia, killing native birds is illegal and legal permits are mandatory for duck shooting.

Bird Deterrents for Dams: When Research and Practice Meet

While different deterrent systems for dams reveal different effectiveness, the truth is that the unpredictable nature of Australia’s birds makes waterfowl control around dams and farms highly challenging. Thus, research and practice should meet to provide effective results in the long-term. On-farm measurements and detailed information (e.g., location, species, avian movements, time of year, food resources) are crucial to help both owners and contractors achieve adequate results.

A mixed approach is often necessary to deter birds from landing on dams. Moreover, deterrence should be started as soon as possible to prevent birds from establishing patterns, especially in contaminated and high-risk areas. Habituation should be considered, too, as birds learn quickly and it’s hard to keep track of their movements.

Note that numerous social and environmental factors also influence bird deterrence; risks of killing other animals, animal welfare, noise pollution, and aesthetic acceptability are all factors to account for. Last but not least, installation and maintenance costs are major factors that both dam owners and experts should consider.

An Alternative Form of Bird Deterrence for Dams

To ensure effective bird deterrence, to eliminate leaks and evaporation in dams, and to provide more usable land, experts recommend the use of underground storage tanks. Such structures can be used to store drinking, rainwater, and wastewater. They are easy to install and relocate and also ensure protection from theft. Interestingly, another option for underground water storage is the use of concrete water storage culverts.

Above-ground water storage, on the other hand, is also an interesting alternative. Self-supporting bladders, for instance, widely used by the Army, are becoming more and more popular in non-dam commercial water storage. As a matter of fact, such water storage techniques are highly desirable as they do not disturb wildlife and humans.

Because when it comes to wildlife, we should admit that human activity often causes disturbances to wildlife habitats. While the construction of dams is essential, especially in arid areas, human-caused changes can lead to unpredictable changes in bird breeding, resting, groundwater levels, and local climates. Thus, as stated above, research is essential to assess the long-term effects of water reservoirs and bird deterrent systems on wildlife.

Bird Deterrent Systems for Dams: In a Nutshell

Bird deterrent systems, defined as techniques to exclude wildlife from certain areas, vary in complexity, costs, and effectiveness. Some of the common methods used to scare wild birds away include auditory and visual techniques, physical barriers, habitat modifications, and lethal practices. Alarmingly, deterrent systems for dams can be ineffective in areas where birds have already established nesting colonies.

As keeping track of species, seasonal changes, and costs can be challenging, an alternative form to deter birds from landing on dams is the use of above-ground and underground water storage tanks. Such methods not only eliminate possible health and economic risks associated with wetland birds, shorebirds, and waterbirds, but also ensure high portability and more usable land. Besides, such water structures do not cause undesirable changes to wildlife and local climates.

To sum up, dams are refreshing sources of life sprinkled across Australia and the rest of the world. At the same time, water reservoirs attract wildlife and diseases, which can be detrimental to livestock and humans. Though bird watching can be highly rewarding, farm owners should always employ effective bird deterrent systems for dams – methods that are a tough egg to crack.