Question

Many different species of songbirds migrate into the United States and Canada from Central and South America each summer in order to take advantage of the caterpillars and other insects that hatch in the northern forests during the summer. Over the past several decades songbird populations have been declining. How might a decrease in the number of songbirds be expected to affect the trees in a northern forest?

Answer 1

  The trees in the northern hemisphere will be very negatively effected by the declining numbers of the migrating songbirds.

  The reason for that is that the songbirds are the predators of the caterpillars. With the declining number of the songbirds, the caterpillars will grow in numbers.

  The caterpillars are feeding on the leaves of the trees. As the numbers of the caterpillars grow, they will eat more and more leaves from the trees, thus making huge problems for the trees because they will not be able to properly perform the photosynthesis which is crucial for their survival. The trees will start to get diseased and lot of forests in the Northern Hemisphere will be destroyed.

Answer 2

The main way in which a decrease in the number of songbirds might be expected to affect the trees in a northern forest is that the would be overrun with more instincts due to a lack or predators.