It has been a week of heartbreak on New Zealand's Farewell Spit, with an unexpectedly happy twist.
In two separate mass strandings, more than 650 pilot whales beached themselves on the thin strip of land — and over 350 of those died there over the past few days. When volunteer rescuers left the beach for the night Saturday, hundreds of survivors from the second stranding remained ashore.
Then something curious happened: When the people returned Sunday morning, almost all the surviving whales were gone. All but 17 had left the beach and returned to the waters of Golden Bay overnight.
"We had 240 whales strand yesterday in the afternoon and we were fearful we were going to end up with 240 dead whales this morning," Herb Christophers, a spokesman for New Zealand's Department of Conservation, told Reuters.
"But they self-rescued, in other words the tide came in and they were able to float off and swim out to sea."
At high tide Sunday, volunteers managed to send the remaining 17 survivors back to sea. Project Jonah, a marine conservation group helping to lead rescue efforts, said the 17 whales had rejoined the large pod of more than 200 whales about a mile offshore.
It was a remarkable reversal of fortune. On Saturday, New Zealand's Department of Conservation had put out an urgent call for help, but by Sunday, Project Jonah announced that there would be no more need for volunteers.
The day's good news offers a happy end to a story that at times seemed unrelentingly tragic.
The initial stranding, discovered earlier in the week, had left more than 400 pilot whales on Farewell Spit, a skinny beach that arcs for miles from New Zealand's South Island into the sea. Though the area is notorious for whale strandings, few people had seen one of this scope before; it was the third largest on record in the country.
Experts posit a range of reasons for why mass strandings like these happen, from disorientation caused by sonar blasts and odd land masses to a desire to protect injured members of the pod. But no precise cause is known.
At any rate, hours after volunteers had sent some 100 of the initial survivors back to sea Saturday, a separate large pod of another 200 whales came ashore.
It was a tough sight for many of the volunteers.
"People seem to have an emotional attachment to marine mammals," Christophers told The Associated Press. "They've been singing songs to them, giving them specific names, treating them as kindred spirits."
After Sunday's success, many of the volunteers gathered to sing a waiata, or a traditional Māori folk song, in honor of the newly departed whales.
The work is not over, however. Even after whales have escaped their stranding, they occasionally will return to beach themselves again unless prevented.
And then there is the issue of the hundreds of whales that died on shore earlier in the week. Andrew Lamason, another spokesman for the DOC, told the AP they may tether the corpses to stakes in the shallow water to prevent them from floating into bays near people's homes.