Gibbons learn the ropes

This exercise is a part of Educator Guide: A Rope Bridge Restored an Ape Highway / View Guide

Directions for teachers: After your students read the online Science News article “A rope bridge restored a highway through the trees for endangered gibbons,” ask them to answer the following questions. A version of the story, “A rope bridge restored an ape highway,” can be found in the November 21, 2020 issue of Science News.

1. What happened on China’s Hainan Island in 2014? How did the event affect the island’s gibbons?

A landslide carved a 15-meter-wide gully through the island’s rainforest, damaging gibbons’ typical route through the forest. After the damage, gibbons were forced to leap across the gully.

2. Based on the information given in the article, how would you define habitat fragmentation?

Habitat fragmentation is when the physical environment inhabited by a species is altered in a way that divides and isolates smaller populations of the species.

3. In general, why is habitat fragmentation bad for gibbons?

The fragmented rainforest could divide the gibbons into smaller populations, leading to inbreeding and those small populations dying out. Fragmentation could also force gibbons to travel over the ground more often, where they are susceptible to potentially harmful parasites, getting hit by cars and fights with other animals.

4. What solution did scientists come up with to repair the damage?

Scientists built a rope bridge across the gully that they hoped gibbons would use to safely cross the gully while trees grow back.

5. How did gibbons respond to the scientists’ solution? Did all gibbons respond in the same way?

The gibbons were slow to use the bridge, but eventually did 176 days after scientists installed it. Many gibbons preferred to walk along one rope while using the other rope as a handrail, or to climb along the ropes using their arms and legs. Male gibbons were not observed using the bridge.

6. How did the gibbons’ response compare with the scientists’ expectations?

The gibbons’ use of the bridge differed from scientists’ expectations. The researchers had thought the gibbons would swing under the rope bridge using their arms, similar to how they swing among trees.

7. What does primatologist Susan Cheyne say about the solution’s potential for wider use?

Hainan gibbons are typically not interested in using new things, so the fact that the animals crossed the rope bridge suggests the solution is effective and well-suited for primates. Conservation groups focused on other primate species might be able to use rope bridges.

8. Could the solution benefit animals other than primates? Explain.

Yes. Scientists observed squirrels and a rodent using the rope bridge. Marsupials might also use rope bridges depending on where the bridges are located, the scientists say.