Newell’s shearwaters once thrived on all the main Hawaiian islands, but after decades of decline, they were added to the U.S. endangered species list in 1975. Today they’re mostly limited to Kauai, where about 90 percent of all survivors live. Because they’re threatened by invasive predators like cats and rats, several young chicks were recently relocated to the island’s first “predator-proof” sanctuary, a 7-acre native habitat encircled by more than 2,000 feet of 6-foot-high fencing.
Like many Hawaiian birds, the Newell’s shearwater has been obliterated over the past century by non-native predators that prey on eggs and chicks. It evolved in Hawaii with few natural enemies, allowing it to nest safely in underground burrows, often around the roots of trees. But when people began introducing cats, rats, dogs and mongooses to Hawaii, these once-safe nests suddenly became easy pickings.
Wildlife refuges can protect important habitats for seabirds, but cats and rats don’t recognize refuge boundaries like humans do. To keep seabird chicks safe from those exotic predators, conservationists have begun to fence off nesting habitats in some parts of Hawaii.
Cats and rats are both notoriously good at accessing forbidden places, but according to KPNWR ranger Jennifer Waipa, this fence is specially designed to keep out even the smallest or nimblest threat to young seabirds. “The mesh is so small that even 2-day-old mice can’t get in, and the fence is buried into the ground,” Waipa tells Else. “And there’s a hood over the top of the fence so nothing can climb over.”
read more: http://www.mnn.com/earth-matters/animals/blogs/predator-proof-fence-seabirds-hawaii
article: Russell McLendon
photo: André Raine/Kauai Endangered Seabird Recovery Project