Body Hair helps Elephants Keep Cool

Body hair in mammals has always been believed to be an adaptation to keep the body warm, but a new study suggests just the opposite. According to a new research published in the journal Plosone, elephant skin hair helps keep the body of the animal cool in the warmer regions it lives in.

The study was conducted by Conor Myhrvold and colleagues at Princeton University and their findings were published on 10 October.

The research primarily found that in both African and Asian elephants, the sparse hair on their body helped them cool off compared to those animals that had a dense hair growth on body which helped them keep warm.

In engineering terms it has been known that lower density of hair on a surface can dissipate heat but the biological and the evolutionary significance of sparse body hair has not been earlier known.

The scientists studied the pachyderms and found that the sparse hair on their body significantly enhances their capacity to keep cool under different scenarios like higher daytime temperatures or less windy days.

The authors add that in furry animals the body hair helps in insulation but as the hair recedes, their comes a tipping point when in some animals like the elephant the hair does the work of releasing heat rather than keeping it within the body.

They also say that elephants need this mechanism most of all because they are very large terrestrial animals and live in warmer climates.

Elie Bou-Zeid, corresponding author on the study, says “Sparse hair increases heat dissipation from the skin of elephants and help the largest terrestrial mammal meet its thermoregulation needs.”

The study is the first to prove that body hair has different functions in different animals depending on the surface density.