By: Chanel Pringle
ENGINEERING NEWS, 28th March 2008
A bird species, the barn swallow or hirundo rustica, which was threatened by the planned construction of the new airport at La Mercy, in KwaZulu-Natal (KZN), will now be protected.
About five-million barn swallows migrate from Europe and roost in the Mt Moreland reed bed every European winter, as the reed bed is the only suitable roosting spot for these birds in the KZN area.
However, the reed bed is situ- ated south-west of the planned development and is aligned with the planned flight path for aircraft at the airport.
Bird conservation organisation, BirdLife South Africa, together with a number of other South African and European stakeholders, has campaigned against the planned airport and its possible negative impact on the reed bed, for about a year and a half.
After an initial environmental impact assessment (EIA) was conducted on the proposed devel- opment at the end of last year, the Department of Environmental Affairs and Tourism approved the development, provided certain conditions were met.
One of these conditions was that flight schedules have to be planned around the flight times of the swallows.
Subsequently, Airports Company South Africa (Acsa) has entered into a partnership with a number of environmental stakeholders to ensure the coexistence of these barn swallows with the new airport.
BirdLife South Africa conservation division manager Neil Smith comments, “Acsa has supported the project by entering into a partnership agreement with BirdLife and other stakeholders to ensure that the swallows are protected.”
To this end, Acsa enlisted consultants to determine the roosting and flocking behaviour of the birds by using advanced radar imagery. The result of the study was that the swallows’ movement would need constant monitoring during the landing and takeoff of aircraft. Acsa says surveys conducted at the reed bed concluded that the barn swallow flocks gather above the reed bed in the late afternoon around dusk.
“The surveys, including the bird detection radar, aimed to determine the number of birds present at the site and, from an aviation safety perspective, the height at which the flocks fly above the reed bed and whether they pose a potential risk for approaching and, or departing aircraft,” explains Acsa.
It adds that the radar data analysis indicated that there are times that the swallows penetrate the approach path of aircraft. Such events occur most commonly during the early morning departures from the reed bed roost site, which occurs before any early arrivals or departures from the airport, and thus limits the potential risk.
Late afternoon flocking behaviour took place mostly below the aircraft approach paths.
However, the surveys concluded that the swallows did on a few iso- lated occasions fly at higher altitudes, but only under certain weather conditions and only a small proportion of the birds flew at such high altitudes, and these events lasted for a very short time.
“It was also found during radar demonstrations done at the current Durban International Airport that a swallow roost exists there in close proximity, about 1 km, of the main runway, yet these birds have never posed a threat to aircraft operating there,” says Acsa.
The company says it can therefore be concluded that a coexistence model between the swallows and the proposed La Mercy airport is possible, with the adoption of the advanced radar technology.
“The EIA record of decision indicates that Acsa has to purchase a bird detection radar, and advise pilots of birds over the roost when there will be a risk. “The reed bed will also be protected,” says Smith.
Acsa has invested in and will implement the same radar technology used by the consultants during the study, at the air traffic control tower of the airport.
Further, it will employ environmental management staff to ensure the effective management of the reed bed.
Smith explains that the conservation of the reed bed and the barn swallows is significant as the number of birds roosting there “represents more than 1% of the global population of this species”. It also represents about 8% of the European population of the species.
In addition, Acsa notes that it has a standard wildlife hazard management programme that is implemented at each of its airports in an effort to reduce the potential harmful impact that birds could have on airport operations, as well as the negative impact its operations could have on wildlife and birds.
Acsa says that airport managers throughout the world recognise that birds colliding with aircraft presents serious problems. The International Civil Aviation Organisation requires airports to have a bird and wildlife control programme in place.
The company explains that birds are attracted to airport grounds to feed or fly over the area from nearby feeding or roosting sites.
“Bird presence at airports and bird strikes need to be properly monitored and logged to establish a clear understanding of the problems and patterns of bird behaviour. “At each Acsa airport a thorough understanding exists regarding the particular bird and wildlife species existing in the area that could potentially pose a threat to the safe operation of aircraft,” says Acsa communications manager Solomon Makgale.
Acsa has established a wildlife hazard management programme in collaboration with the nongovernmental organisation committed to the conservation of Southern Africa’s biodiversity, Endangered Wildlife Trust (EWT).
Makgale says, “Air traffic in South Africa is increasing and it is essential to ensure that international air safety standards are maintained at South Africa’s airports. Acsa entered into a strategic partnership with EWT in 1999 to establish and advise on the implementation of a bird strike hazard reduction programme.
The aim of the project, which is funded by Acsa, is to reduce bird strikes and other interactions between wildlife and airport facilities. Makgale explains that the establishment of bird hazard control programmes at each airport has led to an improved airport safety standard for the country.
To understand bird distribution and bird strikes at or near to the airport grounds, monitoring programmes and data recording systems have been put in place by a team of Acsa and EWT staff.
With a clear understanding of the distribution of problem species in high-risk areas of the airport, environment-friendly management techniques are being developed and implemented to reduce the risk of bird interaction with aircraft.
Makgale adds that the partnership has also established a successful Border Collie dog bird scaring programme at both Durban and OR Tambo International Airports, which has led to a significant reduction in the number of bird strike occurrences.
The dogs belong to Acsa and are handled by wildlife control officers. The dogs and the handlers go through a detailed selection and training programme. “It takes about 18 months for a dog to be trained up by a specialist sheep dog trainer and then there is a transitional training phase where the selected wildlife control officer is matched with the dog and finally implemented at the airport,” explains Makgale.
He concludes that bird risk is well managed at all Acsa airports and that birds do not pose a problem to the safe operation of aircraft.
“This is owing to the effec- tive programmes that have been put in place at previously high-risk sites such as Durban, Bloemfontein, and OR Tambo International airports. At all these sites the bird strike rate has been reduced year-on-year,” says Makgale.
Edited by: Laura Tyrer, ENGINEERING NEWS