How to protect a pregnant polar bear and then a cub near a North Slope oil field

Hundreds of miles from its Southcentral Alaska gas leak that made headlines through much of winter, Hilcorp Alaska was quietly taking steps on the North Slope to protect a pregnant polar bear that built a maternal den near an oil field.

"Our momma polar bear," Hilcorp called the animal in a staff bulletin that laid out protective measures. The bear had carved the den out of a snowdrift late last year, beneath a bridge to the Endicott field.

The causeway, the only road to the man-made island, supports near-shore drilling in the Arctic Ocean. Shutting down the field, which produces 8,000 barrels of oil daily, couldn't be done easily. An alternative ice road likely couldn't have been built in time.

The effort to protect the bear set in motion a unique plan that was capped in spring when a healthy-looking cub emerged — much to the delight of Hilcorp crews and others who helped.

Geoff York, a supervisory wildlife biologist with Montana-based Polar Bears International, called the cub's emergence a success story. Oil-field workers took emotional ownership of the sow, considering it theirs to protect.

"That's often lost in discussions about development of oil and gas and mining," York said. "You can disagree whether development should occur and where, but at the end of the day you are talking about people with shared values who care about wildlife and conservation."

These polar bears might be especially challenged. They belong to the struggling southern Beaufort Sea population hit hard by climate change, as higher temperatures have melted the sea ice bears use as hunting platforms for fatty seals.

Listed as threatened under the Endangered Species Act, polar bears are increasingly on land, scavenging whale carcasses or anything else they can  scrounge, including bird eggs and caribou.

Beaufort Sea bears are eating less high-quality blubber, leading to undernourishment and reduced cub survival. Their numbers have shrunk by hundreds.

Sub-adult females in that group, the next generation of mothers, are seeing the biggest declines, said Christopher Putnam, a U.S. Fish and Wildlife Service biologist who oversees human-polar bear interaction on oil fields.

"The reality of this is that every bear counts now," Putnam said.

The agency's overall strategy is keeping enough polar bears alive to sustain the species if, or when, climate trends reverse.

The cub's survival was especially gratifying, officials said. Hilcorp learned about the pregnant bear in mid-December after a security guard spotted a hole in a snowdrift.

A thermal camera showed the curled-up mother's heat signature in the winter bleakness. It lit up like a "light bulb," said Beth Sharp, Hilcorp wildlife and habitat specialist.

Bears typically don't den near oil-field activity, Sharp said. Trucks rolling across the grated bridge were loud, but the den's snow helped insulate the sound.

Hilcorp immediately contacted the USFWS after the bear's discovery, and with agency approval fashioned a plan to protect the animal. Given its den site, the agency felt the bear could tolerate some activity, Sharp said.

Hilcorp faced fines if oil-field work caused the cub to die or the mother to leave, Sharp said.

The road was trimmed to a single lane, and only essential traffic could crawl past. Planned well upgrades were put off. Workers were ferried in groups, rather than individual vehicles. Stockpiles were supplied at the island operation site, since the road would be entirely shut down when the mother emerged.

Hilcorp reached out to Polar Bears International, which is working with Brigham Young University on a polar bear denning study. Hilcorp supports that study each year, providing lodging, flights and other help, York said.

The groups set up a camera that livestreamed the den's exterior to Hilcorp monitors. Security guards kept constant watch.

Then, for a couple days in mid-March, the mother stepped outside. On March 18, a cub emerged with her. Both were in good shape.

The mother bear's appearance launched a two-week road closure, with Hilcorp flying in supplies and crews by helicopter as the pair lingered, inspecting a pipe and other surroundings as the cub acclimated.

New mothers are "hyper-vigilant" with their cub around, and too much noise can "spook" them away before the cub is ready, Sharp said.

The successful cub birth — publicized early this month by the USFWS and the polar bear group — was a nice change of pace for Hilcorp, Sharp said.

At its Cook Inlet field this winter, the company faced bad press and scrutiny when a subsea pipe leaked methane for months. The leak was fixed in April, after sea ice cleared.

Sharp said Hilcorp goes beyond what's required to protect the environment, but people don't always see that.

"We did this because it was the right thing to do, not for good press," she said. "We're always fiscally conservative, but not at the expense of not doing the right thing."