National Geographic : 2004 Sep
Life out of kilter As temperatures rise, seasonal cues are altered, and life is shifting in space and time. Habitats are changing along with the timing of annual processes like flowering, leaf coverage, migration, and birth. Species that depend on each other plants and the insects that pollinate them, for example-don't always adapt to changes at the same time. In some cases they are slip ping dangerously out of sync.