Birds generally should be considered principle allies with the gardener, in his or her efforts to deal with pest pests which harm the garden plants. Quite simply, the more birds which visit a garden, either as permanent inhabitants, or as short-term sojourners on their migratory path, the less the infestations of pest organisms.
It has been estimated that a bird and her mate, that nest twice per year, parenting about ten chicks, ingest the fabulous volume of some 150 pounds of insects, such as aphids, eggs, and caterpillars. That translates numerically into millions of insects. However, not all birds are chiefly insectivores, but most species feed on insects at those times in the year when additional protein sources are important.
Birds will not entirely eradicate pests from the garden. Fundamentally, it’s undesirable that they do so, because eradication is not the aim of intelligent pest management. Instead, the goal of the gardener should be to limit the population of pest and disease organisms to the point that the damage they inflict is tolerable.
There are two main reasons why this somewhat modest approach to pest management is the more typically accepted one today, as opposed to the more conventional approach based on the use of pesticides. Firstly, it’s impossible to get rid of the insects for long. Applying insecticides is always short term, as many insect species produce over 20 generations in a year.
At the same time, the insecticides may eliminate predatory and parasitic bugs which themselves control the pest populations. Moreover, birds and other wildlife escape from an environment swimming in pesticides, resulting in less restraint on the bugs in the future generations. On the contrary, while there are a wide range of active steps to attract birds to the garden, such as providing food, and water for drinking and bathing, the most necessary method is to desist from applying pesticides, other than in the most extreme circumstances. It is best therefore not to see bugs as enemies, but rather as a important source of food for birds.
It may be suggested that certain birds themselves might be considered insects. In fact, there’s scarcely a species at all which directly damages plants. Including the woodpecker is only seeking bark pests and really minimises the numbers of these damaging insects.
The issue surrounds fruit trees and other crop plants, that a number of birds may perhaps devour at particular times of the year. This however, is not really a very good reason for discouraging birds to go to the garden. The correct answer is to protect the fruit by such means as nets or preferably by making use of decoy plants.
For this reason, as large a number and variety as you can of fruit bearing plants ought to be incorporated in the garden scheme. The idea isn’t to supply fruit for humans, but instead for the birds, thus conserving a good deal of the desirable fruit from getting eaten by the birds. For example species of hackberry, juniper, oak, berberis, cotoneaster, pyracantha, viburnum and many more.