The aviation industry, including airports, takes a lot of criticism over its impact on the environment, but in addition to efforts to minimise harmful emissions, many gateways go to great lengths in terms of habitat management and wildlife protection
The wildlife control aspect of habitat management is very much part of daily business for Swedavia, the Swedish national airport operator, explains Christian Nyberg, manager air/landside maintenance operations at Stockholm Arlanda Airport. Arlanda, the biggest and busiest airport for which Swedavia is responsible, hosts a team incorporating a full-time principal hunter and eight part-time employees who, when not working on wildlife-related issues, serve as technicians, fire-fighters and the like. Swedavia’s other big airports – including Gothenburg and Malmö – also have dedicated wildlife control teams.
The operator of the UK’s biggest and busiest international airport, London Heathrow, also places habitat management matters high on its agenda of priorities. Says Russell Knight, Heathrow’s environmental operations manager: “Habitat management is an essential part of operating a safe airfield in an environmentally responsible way and it supports biodiversity in the local area too. It forms part of our ‘Responsible Heathrow’ strategy, which is our commitment to showing leadership in three key areas of sustainability: social, economic and environmental. The Responsible Heathrow commitment means we will reduce our environmental impact – involving biodiversity management, reducing noise and local air pollution, recycling our water, managing waste and contributing to climate change targets.
“Heathrow commits funding and resources, including a full-time dedicated biodiversity team, who work with airport contractors. Heathrow also works with partners and local stakeholders like the Colne Valley Park Community Interest Company and the Crane Valley Partnership to ensure our efforts our co-ordinated and have greater scale and impact,” Knight adds.
Away from Europe, the importance of habitat and wildlife management is just as important at many US gateways. The Chicago Department of Aviation (CDA), operator of Chicago O’Hare as well as Midway International Airport, has a wildlife management programme that forms what it says is “a critical aspect of its overall mission to ensure safe and secure operations”. The CDA’s Wildlife Management Hazard Plan covers all aspects of wildlife management, including how it develops and maintains vegetation to make it unattractive to wildlife as well as many other actions taken to discourage or remove wildlife from the airfield.
Based at O’Hare is a team of five full-time US Department of Agriculture (USDA) Wildlife Services (WS) professionals. This team’s primary purpose is to maintain the wildlife management programme at the airport. It conducts activities to discourage wildlife from creating hazards and provides expertise and guidance to the CDA and other airport operators on best practices for maintaining the airfield and its surroundings.
The CDA’s Operations section is responsible for maintaining the airfield pavement and landscaping and its role in wildlife management is also critical, because its staff are constantly monitoring and inspecting O’Hare’s property and grounds, which cover more than 11 square miles. The CDA Operations section works closely with Federal Aviation Administration (FAA) air traffic controllers and with the WS team of wildlife biologists and technicians on-site to identify potential wildlife hazards in the airport environment.
As well as the CDA’s Cooperative Service Agreement with USDA WS that provides for the five full-time wildlife biologists and technicians based at O’Hare, the CDA also partners with WS in many other ways. According to Craig Pullins, certified wildlife biologist/district supervisor for the USDA – Animal and Plant Health Inspection Service (APHIS) – Wildlife Services: “This partnership enables WS to minimise threats to aviation and human safety caused by wildlife at and around O’Hare, while having a minimal impact on the wildlife itself.”
RESPONSIBILITIES
Airports’ habitat management strategies must take account of a number of different considerations, and the danger of birdstrikes comes up high on the list of priorities. Certainly the primary goal of Swedavia’s habitat management strategy is to “reduce the risk of collision between aircraft and birds and/or wildlife by means of efforts to identify, document and implement risk assessments of species present both air- and landside”, Nyberg informs. “Our vision is to keep risks to a minimum through targeted interventions, making the airport as unattractive to birds and wildlife as possible.”
Responsibilities and tasking prioritisation can change over the course of any given year. For example, in Sweden’s spring and autumn Nyberg faces a huge increase in the numbers of migrating birds. “During that period, it is important for us to make sure that they find the airport as unattractive as possible,” he says. “This is done by scaring, emptying ponds, taking away possible food sources and so on. It’s also important for us to keep the grass under control, as outlined in our Wildlife Control plan.”
Many factors are driving a change in the approach airports take to improve their biodiversity efforts, but Heathrow’s Knight explains: “The critical factor is a greater awareness of the importance of biodiversity and the benefits it provides, aligned to the commitment to act responsibly towards the communities surrounding the airport.”
Thus, while it’s vital to manage the bird population around an airport, airport operators also often have to think about the preservation of animal life around their gateways. In 2010, an inventory of the biological diversity around Swedavia’s airports (both on adjacent land and grassy areas around the runway) was begun, and a number of points of national, regional and local interest were identified. “The natural inventories carried out will be worked into each airport’s development plan to ensure that consideration is given to areas with great biological diversity,” notes Sammy Albery Hellqvist, Swedavia’s environmental advisor. “For instance, at Visby Airport, a total of 311 different species of plants and animals were found, with 20 of these on the European Red List of Threatened Species.
“Swedavia has also established guidelines for conservation,” he advises. “The guidelines will be integrated into wider environmental and conservation issues informing planning and decision-making without adversely affecting flight safety. It is Swedavia’s opinion that through this integration we will create conditions for protecting and nurturing valuable areas at and adjacent to Swedavia’s airports. The guidelines also state that appropriate preventive compensatory measures are implemented in all projects where land impact occurs.”
During those times when an airport is looking to expand, environmental matters have to be carefully addressed by the airport operator concerned. When developing Terminal 5, Heathrow’s biodiversity team transported an entire habitat to a new location along the River Colne at Orchard Farm. This helped conserve the wet grassland habitat and several rare plant species found there, including London’s last wild population of the flowering plant water avens.
The operator’s plans for a third runway include a significant increase in the amount of publicly accessible green space around the airport. They also involve the creation of new green corridors that link together existing outdoor recreation areas such as those in the Colne Valley Regional Park. Measures to mitigate the development’s impact on the environment will also be taken, such as addressing any effect on local rivers or implementing flood protection.
An additional runway would provide the opportunity to design wetland habitats to attract a wide range of species – including birds, Knight suggests, “Although we will pay careful attention to ensuring duck, geese and gulls are not attracted to areas where they could present an unacceptable birdstrike risk to aircraft.”
US airports have seen more than their share of expansion. Over the last decade, O’Hare’s airfield has been significantly changed under the O’Hare Modernization Program (OMP), and OMP construction has significantly changed the airfield – by adding pavement in some areas and taking away pavement in others, by demolishing facilities and building new ones. The OMP has also provided an opportunity to develop sites that take wildlife management into consideration, a CDA spokesperson notes.
For instance, numerous green roofs have been created on new airport facilities. The vegetation was carefully chosen from species that are not attractive to wildlife, such as types of sedums. Plus, under the OMP, a new and improved storm water detention basin with a smaller footprint and greater depth was constructed to replace a larger, shallower basin. The design of the new basin is said to be considerably less attractive to wildlife.
One of the biggest opportunities for habitat management offered by the OMP was the replacement of more than 150 acres of low-quality wetlands areas on the airfield. In removing these areas from the airfield, the CDA committed to creating three times the amount (450 acres) of high-quality wetland areas in more suitable, desirable and accessible locations in north-eastern Illinois.
Meanwhile, the CDA has worked with the WS team at O’Hare and Wildlife Services’ National Wildlife Research Center (NWRC) to incorporate endophyte-infected fescue for all OMP turf grass projects. Published NWRC research shows that grass infected with endophytes may be less attractive to some wildlife, such as Canada geese, compared to turf grass traditionally planted at airports. Management of the new or existing vegetation is just as important as what is planted and the CDA works to maintain all vegetation on the Airfield Operations Area (AOA) to eight inches or less as recommended by the FAA and WS, the spokesperson insists.
In addition, the WS continues to work with the CDA and the OMP to install overhead grid systems across all the creeks on airport property, in order to reduce their attractiveness to Canada geese. The WS team also co-ordinates with the CDA to ensure all storm water drainage ditches remain free of vegetation. This allows water to flow off the airfield as quickly as possible and prevents ditches from attracting wildlife. These habitat management efforts, coupled with the USDA WS’s active wildlife hazard management, have reduced the number of reported damaging strikes involving species of waterfowl, Pullins points out.
HAZARDS
The decisions the CDA makes about landscaping, such as tree plantings outside the AOA, turf grass planting and management, and areas where water is collected, all have important implications for the presence of wildlife at the airport, the CDA spokesperson explains. Moreover, when wildlife is present on the airfield, the WS team takes steps to manage it in the most effective and humane manner possible as outlined in O’Hare’s Wildlife Management Hazard Plan – annually provided and approved by the FAA.
The WS team uses an integrated wildlife damage management approach to managing wildlife hazards to aircraft at O’Hare. Each situation or encounter with wildlife on the AOA generally requires a different approach to mitigate the hazard but many approaches commonly used at other airfields are also used at O’Hare. Although not unique to O’Hare, the WS team has a large comprehensive raptor trapping and relocation programme, for example. Airfields in general are very attractive habitats for raptors due to the managed vegetation and numerous perching opportunities. Therefore, says Pullins, the WS team works year-round to relocate raptors from the airport.
To investigate the efficacy of its wildlife management efforts, the WS team also undertakes extensive research on its wildlife management programme. Projects have included investigating: the efficacy of O’Hare’s red-tailed hawk relocation programme, including red-tailed hawk movement and habitat use near O’Hare and after relocation; the efficacy and implementation of an avian radar system at O’Hare; wildlife’s attraction to green roof installations versus traditional rooftops; and the impacts of grazing animals on plant and wildlife communities at O’Hare.
As we saw with Swedvia above, it’s important to be aware of how the environment changes throughout the year, the CDA stresses. Given Chicago’s geographic location and the fact that the region experiences very different conditions during all four seasons, the biologists must have expertise on bird migrations, such as what species to expect and when they anticipate their presence at O’Hare. In response to increased wildlife activity during migration periods, the WS team expands its coverage at O’Hare to seven days a week during peak migration periods.
Another consideration is to understand how prey populations on the airfield attract other wildlife, and how they can be monitored and managed. As prey, small mammals attract both raptors and mammalian predators, such as coyotes. The WS team in Chicago conducts bi-annual small mammal surveys to maintain an index of small mammal populations living on the AOA. In addition, management of small mammals has been conducted to reduce their population on the airfield and subsequently decrease attractiveness to these predators.
In addition, both the CDA and the WS team utilise pyrotechnics to haze and harass wildlife from the airfield, which also deters wildlife from entering the airport environment.
Within Heathrow, there is a wide range of biodiversity measures to minimise birdstrike risk, including the continuous management of grass areas and planting design. The gateway’s conservation sites are monitored frequently to assess biodiversity impacts and ensure the airport operator’s actions are appropriate and deliver the most benefits.
Outside the airport, Heathrow Airport Limited’s work with partners ranges from co-ordinated surveys and the sharing of information to volunteering and joint initiatives and projects. Since 2014, it has also trialled wildflower planting in some areas of the airport as a way of further enhancing biodiversity, reducing birdstrike risks and providing a more pleasant landscaped environment around the airport.
As alluded to above, Heathrow’s plans for expansion – a major talking point in the UK both within and beyond the aviation sector – include enhancing the scale of its biodiversity responsibilities and surrounding the airport with significant areas of new and enhanced parkland, providing a connected 15-mile corridor of publicly accessible green space for local residents and wildlife. “Taken together, the plans would result in new or enhanced parkland that is approximately four times the size of London’s Hyde Park,” Knight observes.
WIDER ENVIRONMENTAL CONCERNS
Habitat management can form part of airport authorities’ wider responsibility for the environment, encompassing such considerations as noise, waste management and the huge issue of harmful emissions. Sometimes there can be a difference in perspective in this regard amongst public and privately owned/operated facilities. Swedavia, for example, is a state-owned company, which means that it is obliged to contribute to the meeting of Sweden’s environmental quality objectives. There are 16 different objectives and these cover issues such as offering a rich diversity of plant and animal life, flourishing lakes and streams and thriving wetlands. “Our guidelines for conservation are based on a number of these objectives, so we feel we have a responsibility regarding preservation of wildlife species,” Nyberg and Hellqvist together observe.
Water management can represent an important aspect of wider environmental concerns for many gateways. Around Heathrow, several conservation sites are also used for airport water management, treating the surface water run-off from the airport that enters local watercourses. For example, Mayfield Farm represents an innovative reed bed treatment plant that not only hosts wildlife, but also treats de-icing fluid coming from the airport using natural processes. The water containing de-icing fluid is transported from Heathrow to a set of reed beds at Mayfield Farm where naturally occurring bacteria can break down around 95% of the glycol in the de-icer, leaving clean water that can be sent back into the local watercourses. “We believe this to be the only computerised reed bed system in the world,” Knight considers.
O’Hare’s operating authority also takes a wide-ranging view on its environmental responsibilities. “In many cases, the actions the CDA takes to improve sustainability at the airport can also benefit the wildlife management programme,” the spokesperson says, suggesting that a good example is to be found in the grazing herd that the CDA has hosted at O’Hare over the last three years to help manage overgrown vegetation. The goats, sheep, llamas, burros and alpacas offer a sustainable alternative to vegetation management that would otherwise be performed with equipment that produces emissions. The removal of overgrown areas, especially in hard-to-reach places that the animals are so adept at getting into, also reduces the habitat of wildlife, such as birds, that can be hazardous to flight activity.
DOING MORE
Many airports have won praise for their work and their record on environmental management. Since Swedavia started inventorying biological diversity at its airports, the operator has undoubtedly received plenty of attention both in the media and from interested institutions and individuals – university biologists and so on. “This has definitely strengthened our brand and our supervising authority is nothing but positive regarding our work in this regard,” Hellqvist suggests.
At the UK’s busiest airport: “Balancing biodiversity protection and enhancement with aircraft safety is a complicated challenge and one where Heathrow has achieved some notable success, but it plans to do much more,” Knight says. “We believe expansion would create a bigger and better Heathrow, and that it creates an excellent opportunity for us to not only expand and strengthen our biodiversity responsibilities, but also to establish and recreate locally distinctive habitats lost historically through urbanisation of the wider area.”
Pullins at the USDA WS is in no doubt of the importance of the issue: “All airports should focus on habitat management issues. Wildlife are attracted to food, water and cover for their life cycle needs and airports often possess habitat that provides at least one component – and often a combination of all three components. Therefore, habitat management is the foundation of wildlife hazard management at any airport.
“Investing in habitat management can sometimes have more up-front costs; however, the investment will yield long-term benefits. Habitat management will decrease the attractiveness of the airport to wildlife.
“Every airport, however, is unique due to its location,” he goes on. “Differences in geography, climate, surroundings and vegetation can interact and contribute to wildlife hazards to aviation. Even the type of aircraft and its operation can factor into the equation. Each airport’s individuality requires an assessment of the specific hazards and a management plan with methods and resources appropriate to manage the hazards.”
Currently, at O’Hare and the other airports where the USDA WS provides service, more than 90% of the wildlife encountered is dispersed, or chased away, from where they might cause a hazard and capture/relocation is used when feasible, Pullins says.
