Hallowed grounds the world over are becoming refuges for a variety of threatened species.
The Three Sisters Caves along Kenya's coast house bat guano knee-deep in some places. The ground skitters with cockroaches and whip spiders the size of a human fist. A bat corpse one morning could be picked clean by the afternoon.
For all their creepy critters, the caves play a crucial role in preserving biodiversity against the threats of agricultural encroachment and illegal logging, thanks to their sacred status among the local ethnic groups.
The site's significance to the local population provides unofficial protection, and new research shows that the area is home to large numbers of plants and animals, including several threatened species.
"There's accumulating evidence from around the world about how important sacred sites are for conservation," said Jan Salick of the Missouri Botanical Garden in Saint Louis, who found in an earlier study that sacred sites in Tibet harbor more species than non-sacred sites.
Other studies have made similar discoveries around the world from India to Japan to South America, Salick said.
"While sacred sites are not created for biodiversity conservation, they still contribute to protection of ecosystems and conservation," Salick said.
A different approach to conservation is needed to support such sites as biodiversity refuges, she added. The old style of conservation placed people as the enemy of protection efforts.
"(In the old approach), humans had to be extracted from nature to conserve nature. This is just the opposite," she said.
Historically, the Three Sisters Caves served as refuges from slave traders and during tribal conflicts. They were also used for traditional ceremonies and religious practices, said study lead author Kristian Metcalfe of the University of Exeter in Penryn, Cornwall.
Metcalfe, with the permission of elders from a local village, surveyed parts of the caves, crawling through the guano and cockroaches to catalog the caves' species.
His study, published in the journal Oryx, revealed that the caves and their surroundings house 121 species of plants, including nine considered somewhat rare.
He also found 46 types of animals, including frogs, baboons, butterflies and bats. The Hildegarde's tomb bat found in his survey has only been recorded in nine locations in Kenya, Tanzania and Zanzibar, and Metcalfe's survey added the caves as a new location.
"Sites preserved by indigenous cultures can be important for conservation, especially in places where there is a lot of agricultural encroachment," Metcalfe said. "These have the history and traditional values that stop people going into them. Forests that don't have these beliefs are encroached."