AIRFIELD BIRD SCARERS

Over the decades, many tricks have been tried to scare or deter birds from the vicinity of airfields.

1. I recall in the early '60s Cartridge 1.5 inch Bird Scaring fired from a standard signal pistol which would arc into the sky and explode with a loud crack. These were discontinued from use near runways due to debris from the 'cracker' damaging aircraft tyres and being an ingestion hazard (FOD) to jet engines.

2. Long grass, i.e. letting the grass grow long so that birds would not settle. Some species still did.

3. ATC vehicles playing tapes of bird alarm calls.

4. Deployment of actual birds of prey under ATC control.

But, another odd one appeared when I was at Butterworth in (then) Malaya in 1962. We took receipt of two boxes containing what appeared to be an old fashioned gramophone. The main item was very large metal horn. Being seen as a bright ex Apprentice, the boss charged me to assemble them and find out what they were and how they worked. He said that they belonged to Air Traffic Control and were 'bird scarers'

I spent a couple of hours following the assembly instructions and deduced that the base was a gas tank into which a measure of Calcium Carbide was poured. A water tank above it was filled and an adjustable valve allowed water to drip onto the carbide which produced acetylene gas. The gas fed into a thin metal bellows which gradually inflated and extended vertically. At extremity an attached linkage tripped and open a valve so that as the bellows collapsed a puff of gas was shot into the horn. At the same time the linkage triggered a lighter flint mechanism in the horn and fired the gas/air mixture with a mighty bang.

The rate of water drip and extension of the bellows was adjustable so that the number of 'shots' per minute could be regulated and - to a degree - the noise level.

These contraptions were then placed strategically on the airfield and operated causing the local seagulls much consternation. They were judged an instant success but it was short lived. ATC in an effort to make the sound more directional took to putting the scarers in 45 gallon drums (200 litre) laid on the side with one end removed. After just a week in daily use, it was not unusual to see a gull standing on the oil drum as the scarer fired and barely lifting off before settling back again to preen its feathers!

I did a quick Google to see if theses contraptions are still around and found may links. This one should be of interest to airfield operators:

www.defra.gov.uk/environment/noi ... caring.pdf

Do any of our members have experience in bird scaring techniques?

Peter: I remember us laughing our socks off as the fire truck wombled up and down squawking like a demented seagull. When I was at Brawdy in the mid 70s we did some trials of the 'long grass' policy. We had a number of scientists with us for several weeks as they studied the birds and the effects of the long grass policy. Must have been great to get a contract to watch grass grow - better than watching paint dry!

Most military airfields were then established with a Bird Control Unit and I seem to think that 10 or more years ago this task was contracted out. I still see little yellow-painted RAV4s and the like wandering around airfields making demented seagull noises. Every now and again the truck stops, the bloke gets out and waves his arms about, which seems to have more effect than the noises. Some airfields have shoots but after the first shot or two the birds leg it to the adjacent fields.

Farmers put bird scarers in their fields. Around Lincolnshire these days they tend to use 'gas guns' operated by Calor gas. These now seem to make two bangs quite close together and operate on some random cycle. The pigeons take off when they hear the first bang and land somewhere else in the field, not being too bothered about it all really.

A mate of mine is a safety officer at Sydney (YSSY). He specialises in this sort of thing.

One of the techniques he uses is called "Birdfrite" - which is a shotgun cartridge fired from the hip that lobs into the middle of a bunch of birds and goes off with a considerable bang. Bigger birds might actually be shot with a rifle if they begin to affect aircraft operations. They leave 'em alone if the birds are not causing issues. It's not just birds either - he once got 20 rabbits in a night...
They also have gas cannons (a similar aim to that described in the original post) - essentially a propane cylinder connected to a spark generator that has four exhaust ports on top. On triggering, each port fires in rapid succession - bangbangbangbang. There are remote controls in the safety vehicles to trigger the cannons. There is usually a short delay between pushing the button and the cannon actually firing. This led to one of my mate's best stories. He once pushed the button, just as a little willy wagtail landed on one of the exhaust ports.

"Oh dear, I hope for his sake he is not on the first one to fire", said my mate...

Bad luck, bird. He was perched on the first exhaust port to fire... exit bird in five different directions, a large lump of meat landing with a splat just in front of the vehicle.

My mate doesn't demonstrate the gas cannon to anyone after that!

Another common issue in these parts are fruit bats. They are apparently harder to scare (and smellier to clean off aeroplanes...)

Over the years and up to date, I've often had a cuppa with the bird scarers on the airfields I've worked on. They've got all sorts. Guns that fire a flare with a loud bang, shot guns, a loud beacon/speaker that squaks like a bird of prey and all sorts. Generally nice chaps too.

Airfields still have the long grass, which does in turn attract others, such as hairs/rabbits. I have fond memories of changing runway lights and transformers, being parked on the grass in summer, then driving to the next light and seeing half a dozen hairs scared by my vehicle (possibly my driving also), then running out of the grass and across the runway, which was active even though I was at the edge working!

That was what was called a "gas cannon", never seen them used in the RAF myself. Apparently birds got used to them do they were withdrawn.

Yes done some bird scaring myself, and seen a few birdstrikes.

Thanks for that. I enjoyed the replies.

Yes, the item I described belongs to a group now collectively referred to as 'Gas Cannons'. Now they are all powered by bottled gas instead of acetylene. The march of progress.

Careful guys, there is a 'bird scrarer' amongst you!
Long grass is a misleading title as it is simply known as 'Long grass policy', the grass is actually fairly short, or certainly should be. When at 4-6 inches the grass forms a springy and stiff sward, this puts birds off from settling in it, also birds like to be constantly looking out for enemies and danger, 4-6 inches prevents most grass settling species from being able to do this.
If grass gets longer than this it tends to start bending over on itself, it goes softer and can cause a good climate for insects to prevail in - thus attracting feeding types.

Gas canons are a complete waste of time - they scrare the birds off (usually in an uncontrolled and scattered way) at one particular time, but they soon habituate to the disruption and return and eventually get used to it.

Bird control is a carefuly researched, recorded, and practised role, or at least it should be - thats why the MoD and some civil airports spend a fortune on it! Surprise and control are the best weapons for bird controllers.

Always remember seeing a thick civvy putting out bread for the birds at Leuchars, he seemed quite suprised by how loudly I shouted at him!

canberra wrote:

Always remember seeing a thick civvy putting out bread for the birds at Leuchars, he seemed quite suprised by how loudly I shouted at him!

Yeh! He should have known they prefer corn.