Two new species of frog have been discovered in fast-disappearing forests in the Philippines, boosting hopes for the survival of the country's rich but threatened wildlife, scientists said Tuesday.

The new discoveries are a mottled brown frog with red eyes and a broad yellow stripe running down its back, and a yellow-green one not much bigger than a human thumb, British-based Fauna and Flora International said.

Country director Aldrin Mallari said the finds should boost conservation efforts in the Philippines, which has extremely diverse plant and animal life but where many species are threatened by extinction.

"Many (environmental) institutions and funding agencies have written off the Philippines because we only have 20 percent of our forests left," he said at a forum at the National Museum where the finds were announced to the public.

"Yet many of these species, even if they are threatened, have this resiliency."

His team discovered the frogs in Leyte island's Nacolod mountain range in November last year. Their dwindling habitat also harboured 62 other reptiles and amphibian species, 36 mammal species, 112 bird species, and 229 plant species.

"A lot of these are critically endangered because of fragmentation," Mallari said.

The Nacolod range's once-expansive forest cover is almost gone, with trees cut down for timber or burnt off to free up land for farming, he said. The remaining patches of forest are no longer visible by satellite.

The long-term survival of the diverse species will depend on the Philippines' ability to protect habitats from further exploitation, Mallari said.

The brown frog specimens measured about 43-55 millimetres (1.7-2.2 inches) while the yellow-green ones were 20-27 millimetres (0.8-1.1 inches) long. They have not yet been formally named.

US-based Conservation International lists the Philippines both as one of the 17 countries that harbour most of Earth's plant and animal life, and a "biodiversity hotspot" due to massive habitat loss.

Theresa Lim, wildlife protection chief of the Department of Environment and Natural Resources, told the forum that despite this, apart from the frogs 36 new plant and animal species were discovered in the Philippines in the past 10 years.

"We have to do something. We don't want them to disappear immediately after they are discovered," she said.