Set in the cartoon world of the 1900’s the TV show originally broadcast from September 1969 focuses on the efforts of Dick Dastardly and his canine sidekick Muttley in catching Yankee Doodle Pigeon who carries secret messages (as pigeons do!) In reality, pigeons were considered an essential element of war time communication from as early as Julius Cesar right through until the great World Wars.
From May 2019 the discussion around Biodiversity, Farming, Wildlife and the opinions of Natural England that pigeons be removed from the ‘shooting vs conservation’ debate has abounded. It was stated that instead of shooting ‘other satisfactory solutions’ for their exclusion from farmland be found so as to prevent serious damage to crops.
From my observations over many years, pigeon grazing on Winter Oil Seed Rape regularly accounts for greater losses that Slugs or Cabbage Stem Flea beetle. We have some wonderful crops of rape this year, I just hope they will all still be there on the 1st of March and not obliterated by pigeon grazing.
Looking back to 1985 ADAS and MAFF had a series of leaflets detailing birds and bird scaring. It was recognised that preventing birds from damaging crops was essential. At the time suggestions were made about planting vulnerable crops in fields in close proximity to where sufficient day-to-day human activity could deter birds. In other words, scaring them can be effective in protecting crops.
For a scarer to work it needs to instil a sense of fear or be something uncommon or unexpected, or it needs to mimic natural events that are unpleasant. The efficiency of the majority of scares is depends on the production of unusual visual patterns, bright colours or unexpected sounds.
When faced with an unexpected object or noise a bird may either approach and explore it or flee from it. For scaring to be effective it is desirable to enhance those properties that cause flight and reduce any that encourage the birds to approach.
Birds are thought to build up a mental picture of their surroundings which leads them to expect certain things in certain places. (One of the attributes Yankee Doodle pigeon was thought to utilise when on a mission!)
Birds become suspicious when they encounter something different; the extent of the difference is thought to determine whether they explore or flee from the object.
A small difference is believed to produce an exploratory reaction, or a bird becomes familiar with the object until finally the object is ignored. In these case’s the scarer provides protection for only a relatively short time.
Since birds quickly learn to ignore happenings of no importance to them, such as those not connected with the presence of predators or mates some scarers mimic signals that are associated with danger. Such devices resemble predators such as hawks or owls or may copy the alarm signals given by a bird when faced with a predator.
Birds should continue to react to these devices even when regularly encountered since in the wild any individual not responding quickly or persistently to the presence of a predator is unlikely to survive.
The basic rules to maximise the effective life of any scarier is therefore to reduce the speed at which birds can gather information about it.
Use one type of scare infrequently.
Use a variety of “scare tactics” rather than several of the same type.
Immediately remove any scarier that has lost its effectiveness.
Alter the position of scarers as frequently as possible.
Reinforce the deterrent effect of scarers by shooting.
Camouflage auditory scarers that have no visual effects.
Position auditory scarers to produce the maximum noise.
Control the times of use and operating rates of auditory scarers.
Attempt to reduce the feeding pressure on the susceptible crop by other appropriate measures.