Researchers found that chimpanzees actually prefer a firm bed.
The research team noticed that chimpanzees tend to choose "beds" of Ugandan Ironwood. The researchers believe the chimps choose this material because of its " firm, stable, and resilient properties," a PLOS news release reported.
Chimpanzees often use tree branches and other types of wood to build their beds in trees. Researchers noticed the primates select certain tree species to nest in more often than others, but were not sure why that phenomenon occurred.
The researchers looked at what physical properties the chimpanzees looked for in a bedding tree. They measured the stiffness of 326 branches from seven different species of trees that are commonly used by the monkeys. The team also measured the leaf surface area and determined the trees' "structure and architecture."
Out of 1,844 nests sampled the chimpanzees used Ugandan Ironwood for 73.6 percent o their nests. These trees only represent about 9.6 percent of the trees in the sample region.
The researchers found the ironwood was the strongest and stiffest of other types of wood in the region; it also had the greets bending strength and the smallest space in between leaves on the branches, and the largest surface area.
These properties are believed to "provide protection from predators and pathogens, as well as provide temperature regulation and comfort," the news release reported.
"Chimpanzees, like humans, are highly selective when it comes to where they sleep. This suggests that for apes there is something inherently attractive about a comfortable bed--down to what kind of wood you use to make it," David Samson from the University of Nevada said in the news release.
The study was published under the title "Chimpanzees Preferentially Select Sleeping Platform Construction Tree Species with Biomechanical Properties that Yield Stable, Firm, but Compliant Nests" in the journal PLOS ONE.
