Hawai'i Volcanoes National Park is reporting a promising start to the nene nesting season, with 33 pairs laying eggs or tending to goslings in an area stretching from the Kilauea coastline to the slopes of Mauna Kea.

Officials have temporarily closed certain areas of the park to protect the rare geese from human disturbance during this sensitive time.

Unlike geese on the Mainland, nene begin breeding in the fall when ample rain helps provide plenty of plant growth for foraging. This allows the birds to fatten up before nesting and helps ensure that goslings hatch when food is most plentiful, said park biologist Kathleen Misajon.

With a long breeding and nesting period that runs from September through May, Misajon said she expects an additional 10 to 15 nesting attempts as the season progresses. The endangered geese, which mate for life, usually lay between two and five eggs, which have an incubation period of 30 days.

The birds breeding within the Big Island park range in age from 2 to 23, Misajon said. "It's not that common to see wild nene in their 20s still producing offspring," she said.

The oldest breeder, a 23-year old gander, was observed last month guarding his nest for 30 days while his 6-year-old mate incubated three eggs on a near-barren lava flow. A day or two after the eggs hatched, the pair was seen escorting their downy brood more than two miles to an area where they could feed on berries, seeds and grass, Misajon said. It was a perilous journey, with the adult birds and their tiny, 3-ounce goslings traversing rocky patches, thick brush and the park's main road and a major highway.

Other nene have not been so lucky. In November, two geese preparing to nest were killed by a car, and an adult nene at Haleakala National Park on Maui also was killed by a motorist.

There are about 180 nene in Hawai'i Volcanoes National Park, which last year celebrated its most successful breeding season ever, with pairs producing 40 fledglings — goslings that survive to take flight.

Misajon said there is an average of 15 fledglings a season, and the nene population had been declining since 1995, so last season's success and the 23 fledglings from 2005 provided a much-needed boost.

At Haleakala, the news is not so good, as recent rain doomed the first hatchlings of the season.

So far, 22 nests have been observed, and of the half-dozen that hatched eggs, none of the goslings survived, said wildlife biologist Joy Tamayose.

She said the nesting season normally peaks in December and January, but at Haleakala the birds are off to a slow start, perhaps because of a warmer and drier December than usual. Some nene pairs may have lingered to enjoy the favorable weather before settling down, she said.

There are an estimated 250 to 300 nene living within park boundaries, and a good year will see 40 goslings survive, Tamayose said. Last year, only eight to 10 made it.

Bad weather and predators such as feral cats, rats and mongoose are the biggest threats to the young birds.

Tamayose is hoping the Maui nene will recover from their poor start this year. "It's a long season so birds that fail early have a chance to re-nest," she said. And for those that do not, there's always next season. Nene are long-lived, so they have "many chances to bring birds into the population," Tamayose said.

To help protect nesting nene at the Big Island park, Hilina Pali Road at the Mauna Iki Trailhead has been temporarily closed to cars, hikers and bicyclists until further notice. However, the first four miles of Hilina Pali Road remain open, allowing visitor access to Kulanaokuaiki Campground and Mauna Iki Trailhead.

Backcountry hikers are allowed access to trailheads at the end of Hilina Pali Road after registering at the Kilauea Visitor Center.

Outside the two national parks, nene populations are found in the West Maui Mountains and on Kaua'i and Moloka'i.

Reach Christie Wilson at cwilson@honoluluadvertiser.com.