Shearwater deaths alarm residents
HA‘ENA — Five wedge-tailed shearwater seabirds were found dead in Ha‘ena in the area between Tunnels (Makua) Beach and Camp Naue in two separate incidents this summer.
HA‘ENA — Five wedge-tailed shearwater seabirds were found dead in Ha‘ena in the area between Tunnels (Makua) Beach and Camp Naue in two separate incidents this summer.
Two were found dead late last month, and three on Aug. 7.
Wainiha resident Kathy Valier suspects the birds were killed by dogs.
Valier is afraid of the colony being wiped out completely, saying that the killing of five birds can equate to the death of five more birds, as their young cannot live without both of their parents. Shearwater lay only one egg a year.
Valier mentions that shearwaters are nocturnal, and that dog owners need to be wary at night.
“Because the colonies are active at night, if they can keep their dogs contained on their property or tied up, since the adults are on the beach at the night time, that is the time of the day to make sure to keep your dogs leashed,” Valier said.
Valier points out other reasons to be careful near shearwater colonies.
“The wedge-tailed shearwaters are currently nesting, and they burrow on the ground, and so are really quite vulnerable.”
She said time is of the essence.
“I think we need to draw attention to people that the wedge-tailed shearwaters could become threatened because their colony is under attack.”
Wainiha resident Phyllis Hopeck also thinks that dogs are responsible for the seabird killings. “I wish people would take responsibility for their pets. This is a highly preventable issue. People need to keep their predator pets on a leash.”
Dr. Andre F. Raine, the Science Director for Archipelago Research and Conservation, said the state of the body of a bird can identify how a bird died. Raine reviewed the photos and believes the same as the residents.
“I would say 100% that dogs killed the shearwaters in Ha‘ena. The fact that they found the dead birds with a little bit of blood on them and one of them had a broken wing, I think it’s highly indicative of the fact that they were attacked by dogs.”
Raine said that dogs tend to kill seabirds for sport, killing them and leaving them intact but with puncture wounds from bites, and often with broken wings.
Many of the dogs that attack seabirds are likely owned, and so would be well fed by their owners and are not looking to the birds as a food source, he said.
Wedge-tailed shearwater, uau kani, status is least concern, according to International Union for Conservation of Nature Red List.
These shearwater are very common on Kaua‘i. Breeding populations of wedge-tails can also be found on ocean islands throughout the tropical Indian and Pacific Oceans from Madagascar to Mexico.
They can be spotted during their breeding season from March to November as they fly around their coastal colonies and are recognized by their vocalization, which is said to sound like moaning or groaning. They can be found on almost every island in the Hawaiian chain. They have white and black plumage coloration and dark bills.
The largest populations of wedge-tailed shearwaters are in the Northwestern Hawaiian Islands, with 230,000 pairs, and significant colonies can be found in the Southeastern Hawaiian Islands with 67,000 pairs.
Some of the largest colonies can be found on Lehua, and islets off the coast off O‘ahu, Maui and Moloka‘i. Wedge-tails also breed sporadically on the islands of Lana‘i, Kaho‘olawe and Hawai‘i Island.
Although their status is least concern, the wedge-tailed shearwaters are a species that is struggling to survive both on and off island, Raine said.
There are less and less of the seabirds as time goes on.
“The populations of wedge-tailed shearwaters right now is low density because they keep getting killed off by predators,” Raine said.
There are more predators to these seabirds than just dogs.
“Barn owls are efficient at killing seabirds. They will strip the breast or keel of the bird and they take the meat off the neck and take off the head. Pigs will attack seabird burrows by taking them out of their burrow, chewing them up and spitting them out,” said Raine.
“The important point here is that this happens on an annual basis, and the shearwaters are extremely vulnerable. Once these predators come into a colony a number of them can die at a time.”
Wedge-tailed shearwaters play an important part in the local ecosystem.
“Their guano enriches the soil, they bring all these nutrients from the sea including phosphates and nitrates, and they fertilize the native plants that grow on the beaches in coastal dune areas, around naupaka,” Raine said. “They help provide fertilizer for ‘ohi‘a trees. Their guano also enriches the coral and the fish as well, and helps it to grow.”
There also are studies that show that numbers of fish and communities of fish benefit from the nutrients from guano from the seabirds.
There have been several incidents in the past where shearwaters have been killed on island by dogs or other predators.
In Oct. 2019, the Honolulu Star Advertiser stated that state wildlife officials reported that nearly 150 wedge-tailed shearwaters on Kaua‘i were killed by off-leash dogs and feral cats during nesting season.
Six years prior to that, according to state Department of Land and Natural Resources, 80 shearwaters were killed by cats and dogs over a two-month period. In another incident, 35 wedge-tails were killed just above Shipwrecks on the South Shore in November 2019 by a cat or dog.
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Monique Kemper is a lifelong North Shore resident who lives in Princeville and writes periodically for The Garden Island.