Use the green tabs below to open or close for more information.
A bird management strategy may be considered effective when:
Consider the following steps:
As a grower, you don't have a way to measure how many berries birds have eaten that never make it to the processing plant, but you can have a pretty good idea of how many ton per acre to expect to get by learning the average yield of your variety(ies), the age and field conditions of your blueberries before pest birds enter the equation.
For fresh market growers, a proper estimation may be even harder to come by because berries don’t go through a processing plant.
Flock size remains one of the tell-tale indicators of crop loss. A grower can see bird damage in his field and make an educated guess based on ratio of damaged fruit to healthy fruit per bush.
Know what bird species are problematic and the characteristics of those birds. Robins, for example, may be present in your field but do not, in general, have the same potential for economic damage as starlings.
Once you establish the pest bird species you need to target, take note of what might attract these pest birds besides your blueberry crop. Are there neighboring crops that end as blueberries begin?
Note whether or not pest birds come in to the field annually or sporadically. If they don't seem to be a problem every year, what factors might be causing them to migrate your way? A change in weather? An earlier or later blueberry harvest? A change in your bird abatement program? A change in what your neighbor or you have planted nearby?
Consistent pest bird flock size year after year may indicate that something is drawing these birds to your area. If flocks are small or nonexistent one year and momentos the next, then weather, change in adjacent crops or crop management may be a factor.
Deciding the effectiveness of each repellent can be difficult. The capriciousness of Mother Nature prevents mathematical formulas from accurately predicting next year's bird damage.
However, you can estimate based on your own experience and observations, and refer to other indicators, such as past studies to give you an idea for the efficacy of different bird management measures. For netting or durable equipment such as cannons or distress callers, the duration of the technique needs to be factored in as well.
Or a grower can calculate cost effectiveness based on:
You can make a general calculation on the cost effectiveness of a control based on the:
For example, let's say you are a grower with a berry crop yielding $10,000 per acre, and you expect this year's loss to birds without treatment to be 20% of your crop.
This means that the repellent should cost less than or equal to the amount it would save you, or no greater than $1,000 per acre to be considered cost effective.
Look at the New Zealand study for more information on this method of calculating cost effectiveness. (p. 13)
Other Bird Control Techniques
Northwest fruit and berry growers try many tools to get rid of pest birds: canons, bird calls, shiny objects, scarecrows, guns, kites, rejex-it, chemical repellents, netting and traps. Each comes with its own set of advantages and disadvantages.
In a pilot study, Karen Steensma looked at the effectivness of a hawk kite. In that study, the hawk kite acted as an excellent starling deterrent. While more data shoudl be gathered, hawk kites may be an option for growers interested in taking advangage of such low cost raptor mimics.
In the case of using raptors for bird management, the risk of potential profit loss without proper bird management may make the cost of abatement falconry a smart investment. If a grower has tried previously ineffective methods, has neighbors who don’t like the noise of other techniques, has environmental concerns, or a desire to market his farm better, abatement falconry may be a serious consideration. To assess the cost of abatement falconry, see the Abatement Falconry Business Models page.
Each grower has to take into account individual considerations. Designing a management program when using raptors does not involve many considerations that would differ from things you might consider for other types of bird management.
When designing a management plan with raptors consideration the following:
Bird management strategy must begin before fruit ripens, feeding habits of birds become established, and/or before birds begin nesting. Once the pest birds have nested they are not going to leave their young; however, a raptor can haze them to the point that the adults will forage elsewhere and spend minimal time in the crop until their chicks are gone, at which point they leave.
Once the first batch of juvenile pest birds come they are easier to deter as they are still trying to figure out how and when to forage. Over time the birds become desensitized. Food is their ultimate goal, and they’ll tolerate a lot of hazing to get to it. As the number of flocks increase, the more difficult they will be to deter.
5261 North Princeton Street
Portland, OR 97203