Folklore has it that jackals are opportunistic survivors. Now scientists have discovered that, true to stereotype, jackals living on a remote island with no freshwater have managed an extreme adaptation to survive in the marine ecosystem: they meet their body’s metabolic requirement for water by licking dew off leaves first thing every morning.
Pirotan is the eastern most island in the Marine National Park in Gujarat’s Jamnagar district. Located 12 km from the coast in the Gulf of Kutch, Pirotan covers an area of around 3 sq km and is partly submerged during high tide. According to a paper published recently in the Journal of Threatened Taxa , the island is home to about 45 jackals.
A team of scientists had landed on the island to study coral transplantation. While researching corals, they got a chance to observe the behaviour of jackals. “We were surprised to see jackals licking dew in the morning. In the night, too, we could hear some sounds which we later established as jackals munching crabs. The jackals are the only large mammals on this isolated island amidst marine fish, crabs and corals,” said Rethnaraj Chandran, a researcher from the Zoological Survey of India (ZSI) and one of the five co-authors of the paper.
A scat analysis of the animals revealed that crabs made up 89.5% of the jackals’ diet. This was another crucial adaptation, as it served as a supplementary water source. “Although the island has no natural water source, the jackals have adapted to manage their water needs from the crab meat. It was also observed that jackals lick dew on the leaves in the morning just after sun rise,” the paper states.
C. Satyanarayana, a coral taxonomist and a co-author of the paper, said that it would have been impossible for jackals to survive on the island had they not adapted to manage their water needs from the resources available. Kamraj Ramkumaran and Kailash Chandra from the ZSI, and Tikardar Shyamal, a forest officer from Gujarat co-authored the research.
