Thursday, 23 January 2020

Ancient Bat Guano reveals secrets

Ancient bat guano like sediment cores, ice samples and tree rings, can be used to study the climate of the past. Artibeus jamaicensis is one of the species that contributed to the guano researchers used to study the climates of the past.

Deep in the forests of northwestern Jamaica, a secluded cave has sheltered an unabridged account of the environment since the early Bronze Age. The cave’s inhabitants live in near-total darkness, swarming out to feed at night through a mist of their own urine and retreating back inside to roost. The colony of bats then add to the archived climate record much as their ancestors did before them: by swooping down from the walls and defecating on the cave floor. With its high levels of nitrogen, guano from bats and birds has been harvested as a natural fertilizer.
Wars have even been fought over the treasure: In 1864 a naval conflict broke out between Spain and Peru over the Chincha Islands, covered in guano deposits said to be over thirty meters, or 100 feet, tall. Radiocarbon dating put the base of the core at around 4,300 years old, long before the first humans arrived. The lead levels in the guano core experienced a sharp uptick after 1760, the fingerprint of coal combustion that propelled the Industrial Revolution.