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? the trees would not be affected if there were fewer songbirds since the birds only eat insects and would not be feeding off the trees. the trees would stop growing if herbivorous insects damaged their leaves at all, so there would be very little new growth in the forests. the trees would suffer more leaf damage as herbivorous insect populations increased until the populations of other insect predators increased in response. the trees would produce more seed since fewer birds were there to eat, and more young trees would begin to grow up in the forests.