The Cayman Islands Airports Authority has reiterated that the shooting of birds is a regrettable but necessary part of its hazard management programme.
Various organisations on Islands have received complaints from concerned member of the public on the shootings.
“There are times when our neighbours do not recognise the situation that the airports authority is in and the responsibility that is put on us to protect the passengers and the airlines,” said Caren Thompson-Palacio, communications and marketing manager with the CIAA.
The issue of bird strikes and the hazard they pose to air traffic was highlighted be the emergency landing of flight 1549 in the Hudson River a year ago after both its engines were disabled when it passed through a flock of Canadian geese. It is estimated that bird strikes cost the airline industry approximately $1,2-billion annually.
Locally the two species that pose the greatest threat are the cattle egret and the great egret. These birds are attracted by the habitat available at the airport.
“The large open grassy areas which comprise the majority of the periphery of the airfield also attract a variety of bird species, both as ostensibly dry grassy areas, and also, after heavy rains, through the formation of temporary pools. Both conditions provide excellent habitat for invertebrates (insects etc.), especially the temporary pools, and so tend to attract large numbers of birds which feed on invertebrates – most notably, in this instance, herons and egrets,” said Mat Cottam of the Department of Environment.
According to Andrew McLaughlin, senior manager, safety management systems with the CIAA, the organisation uses a number of different methods to control wildlife on the airport grounds.
“We use air cannons and vehicles to scare wildlife off the premises – that is our first approach. We also alternate the height of grass on the airside surfaces to deter birds,” he said.
There are also six patrols daily to check on the presence of wildlife on the airport premises.
The main thrust of wildlife hazard mitigation is habitat modification.
“That is the most ecological method and it requires long-term planning to address the availability of food, water and shelter for the animals. The goal is to make the airport as unattractive to the hazardous wildlife as possible, with maintaining the ecological soundness of the area,” according to McLaughlin.
Cottam agreed that habitat modification is the best option.
“If there is a simple answer to this problem, it is to make the airport an unattractive habitat for these key species: less habitat – fewer birds – less problem,” he said.
As a last resort, the airports authority uses ‘lethal control’ which involves the shooting of birds that pose a direct hazard to air traffic.
“It is practised by a trained marksman under permission of the Governor’s office to strict safety protocol. We notify the local police and our own security officers are alerted to instances of lethal control,” said. McLaughlin.
The marksman uses a shotgun with target shot, which is very fine and has a very short range, thereby safeguarding the public.
These methods are only instituted once a bird is judged to be a threat to flight operations.
“Once they encroach into the manoeuvring area, which is a critical area for aircraft operation departing or landing, that is when we sound the alarms,” said Walter Ebanks, senior manager of air navigation services.
The decision to implement lethal control is made between two hours and 90 minutes before flight operations.
According to McLaughlin, the air cannons used by the airports authority had very little impact on the birds when first introduced.
“When we first started using the air cannons, we could walk right up to [the birds] and the air pressure didn’t even scare them out the end of the cannon from a distance of three feet – they just turned and looked at us. After the first instance of lethal control, when they assimilated the same bang with danger, the air cannons worked quit effectively – now much more effectively than they did at the time,” according to McLaughlin.
Although Cottam expressed his reservations about the shooting of birds, he said it was imperative that the best solution be found.
“If a properly conducted study proves that ‘noise plus shooting’ is the best management solution, I think there would be few people who would be willing to risk their lives on a more dangerous alternative. However, in the absence of such a study, I think most people would be interested to know if a more effective solution exists… if only in the interests of self-preservation,” he said.
According to Cottam, a variety of methods need to be employed to be effective.
“Birds are highly intelligent, and soon become habituated to repeated scare stimuli, unless the stimulus is appropriate, well-managed and varied,” he said.
It is not only the birds themselves that pose a problem. According to Ebanks, education forms a key element of their work.
“The key thing is educating those that surround the airport. We’re not out there just doing what we want to do, we’re doing it because we have to do it,” he said.
According to McLaughlin, statistics gathered over the past nine years indicate that Cayman is following the global trend of an increase in bird strikes. This can be ascribed to a number of factors, including increased air traffic and the encroachment of development on the natural habitat of the birds. Better environmental policies and a decreased use of poisons have also allowed bird numbers to recover worldwide.
“The focus now is to try and learn how to live with the wildlife that is present at the aerodrome and control the levels so that they can survive and we can have safe operations, so we have to strike a balance between the two,” said McLaughlin.
However, the instituting of new wildlife hazard management planning at Cayman’s airports seems to be paying dividends.
“Based on what we have instituted in a few short months we can tell that we have made a drastic improvement to incidents of bird strikes on this airport in the last two months,” said McLaughlin.
In an attempt to further improve the operation of the hazardous wildlife management programme, the airports authority has partnered with St. Matthew’s University to conduct a study of wildlife on Owen Roberts International.
The study will span a year, with students from the school conducting regular assessments of wildlife present on the airport grounds. It is hoped that this will allow the airports authority to better manage its procedures in order to deal with any future threat.
The authority has also launched a hazardous wildlife management work group, which will discuss and review current policies. The first two meetings of the group has already taken place.
During the meeting a number of options for wildlife hazard management were discussed, with habitat modification emerging as a very important factor.
McLaughlin said one of the priorities is to improve the drainage of the airport, as any flooding of the grass surrounding the runway drives invertebrates to the surface, which then serve as a food source for many birds, including cattle egrets.
Another important issue was the impact properties surrounding the airport can have on wildlife hazards.
Under the regulations that govern airport safety, the airports authority is responsible for whatever happens within 10,000ft of the airport, and should be consulted on any development that takes place within 13 kilometres of the airport.
The consensus at the meeting was that, although regrettable, the shooting of birds has a role to play in hazard management at the airport, at least for the time being.