Wallabies keep low profile in Koolaus

Answer: The state believes there still are wallabies in the back of Kalihi Valley but cannot be sure because it is not monitoring them, said Deborah Ward, state Department of Land and Natural Resources spokeswoman.

"They're not a species of concern," she said.

However, the state does offer the elusive marsupials some protection. State administrative rules prohibit hunting, killing or possessing brush-tailed rock wallabies.

DLNR Oahu District Wildlife Manager Dave Smith believes the last time the state did a count of the wallaby population was in the early 1990s, before research funding on them ran out. Smith said the population might have been as high as 75 but has probably declined since then.

The scientific name for the brush-tailed rock wallaby is Petrogale penicillata.

The average-size adult weighs between 13 and 18 pounds. Its head and body measure just less than 2 feet long, and its tail is slightly longer. Its color is predominantly brown, with gray fur on its shoulders and reddish brown on its rump.

The shy animals with long, bushy tails and small ears were introduced to Oahu from Australia in 1916, when a pair of breeding adults escaped from a private zoo in Alewa Heights. Their progeny have established themselves on the steep, rocky cliffs on the Ewa side of Kalihi Valley beyond the reach of predators like cats and dogs. They feed on Christmas berry bushes -- another introduced species -- and are not considered a threat to the environment.

Australian researchers looking for a conservation resource for the endangered brush-tailed rock wallabies of New South Wales did DNA studies on the Oahu wallabies. They found the Hawaiian wallabies are genetically closer to the more common northern Australian populations in southeastern Queensland.