1.   As the arms race wore on, the average height of trees in the forest canopy went up.

2.   Gibbons communicate and hold territories by means of loud hooting voices that carry through and over the forest canopy.

3.   He could see the sky through the gaps in the forest canopy.

4.   Keols, invisible in the forest canopy, were calling to each other in their incessant woody voices.

5.   Second, in the forest canopy it was no longer an advantage to live in large groups.

6.   They live mostly on the forest canopy and have white fur crash helmets with black faces and black ears peeping out.

7.   This takes place mainly up in the forest canopy, and so is almost impossible to film from the ground.

8.   American planes would fly low over the forest canopy and release a cloud of chemicals.

9.   An elevated walkway offers a glimpse of the forest canopy.

10.   A dense forest canopy glides into place from above and both sets of wings, lush and leafy or gnarled and decayed, as the situation dictates.