Hobbies And Interests
Seed Dispersal and Fertilization for the Tree
If birds are frequently in a certain tree because their nest is there, their droppings can provide a dispersal mechanism for the tree's seeds. For example, the native kereru pigeon of New Zealand frequents the karaka and taraire trees. This pigeon is the only disperser for large fruit tree seeds in New Zealand because it is the only bird with a beak large enough to eat the seeds of these fruits. Because the pigeon eats the entire fruit, the karaka and taraire trees have their seeds distributed throughout the area in the pigeon's feces. The bird's droppings also fertilize the seeds, making them more viable.
Protection from Insects for the Tree
Since most birds eat many different species of insects, when a bird nests in a tree, that tree is protected from many of these harmful pests. Parent birds feed their fledglings regurgitated or whole insects from the time they are hatched. If the insects are readily available in the tree, the parent birds will also eat the insects there so they won't have to venture far from their nest to feed. Insect pests will eat and suck juices from the tree's stems and leaves, causing injury and potential disease to the tree. Nesting birds save the tree from these harmful, unwanted parasites.
Favorable Nesting Site for the Birds
Many species of birds prefer to nest in trees. Newly hatched chicks are mostly naked and very fragile. Parent birds are anxious to find shelter to help keep their young safe and warm. Trees with dense leaves and branches give parent birds and their offspring protection from wind and storms. Some birds, such as starlings, nest in cavities in trees, which further shelters them. In the spring, competition is fierce for good nesting sites such as those that trees provide. Trees also furnish shelter from predators for the fledgling and adult birds. Parent birds can readily see predators approaching when the bird family is high in a tree.
Food Supply and Nesting Material for the Birds
Most birds eat many different species of insects. Crawling, hopping and flying insects all can be found on trees. Birds that nest in trees eat these insects and feed them to their young. It is an additional bonus for the bird if the nest is in a fruit tree. Many species of birds, such as robins, eat fruit as a large part of their diet. Fruit will also add variety and nutrition to the available food supply for their young fledglings. Trees also provide nesting materials for birds. Several species of birds, including starlings, use fresh green leaves when lining their nests. Many birds also use twigs as part of their nest construction materials.