WILD LIFE | 12.05.17

The Rainforest Next Door

Just minutes from a major metropolis, Malaysia’s Penang Hill rainforest boasts some of the richest backyard biodiversity on the planet.

Photographs by Phil Torres


Uncut, pristine, and a mere 6 kilometers (3.7 miles) from a major city center, Penang Hill defies the commonly held notion of what and where a rainforest should be. It’s neither hard to reach, nor particularly gritty, with an immaculate train providing access and cafés serving visitors who make the 15-minute journey from George Town. And yet, this vast patch of old-growth tropical hardwoods, stretching across some 8,000 hectares (19,768 acres) on Malaysia’s island state of Penang, is home to astounding—and untold—biodiversity.

Pristine forest is becoming increasingly rare throughout most of the world, not least in Southeast Asia, where rainforests continue to be slashed to meet the demand for timber and lucrative cash crops like palm oil. The rainforest of Penang Hill, first protected in 1911, stands as a valuable living time capsule 130 million years in the making, and scientists and conservationists aim to keep it that way. Earlier this year, the Universiti Sains Malaysia and the California Academy of Sciences assembled a team of 117 biologists from nearly a dozen institutions to conduct a comprehensive biodiversity survey of the forest. The researchers hope that their findings—more than 1,400 species of plants and animals, including at least four species that are likely new to science—will contribute to a successful nomination of the rainforest as a UNESCO biosphere reserve. These images capture just a few of the highlights from an intensive effort that the international team hopes will not only further scientific understanding but also help to ensure the long-term preservation of this rare jewel on the Malay Peninsula.

Penang Hill, Penang, Malaysia


With its iridescent turquoise markings and four pairs of eyes, this jumping spider (

Thania bhamoensis

) is well-equipped to recognize and assess members of its own species. The spider’s large central eyes are responsible for acute vision and allow it to differentiate between potential mates and rivals. (Among other differences, females tend to be greener, while males are bluer.) Meanwhile, the spider’s three smaller pairs of eyes can detect movement on all sides, which comes in handy both when fighting off rivals and being on the lookout for potential prey.



Newly hatched stink bugs (Pentatomidae) huddle around the cluster of eggs from which they just emerged. These nymphs don’t yet have fully developed wings, so instead of flying from threats, they rely on the strength of numbers. They will stick together and forage communally until they molt and are able to fly.


The Malayan forest gecko (

Cyrtodactylus pulchellus

) is endemic to Penang, meaning that it is found nowhere else on Earth. These arboreal ambush predators hunt under the cover of darkness, pouncing on prey (mostly insects) as they pass by.


Scientists discover a new scorpion from one of the oldest lineages on Earth. During a nighttime survey of the Penang Hill rainforest, arachnologists Lauren Esposito and Stephanie Loria found this male of a species of scorpion in the family Chaerilidae (a group known as the ghost scorpions) that, until now, was unknown to science. Ghost scorpions, like all scorpions, fluoresce under ultraviolet light, but so faintly that this specimen was an incredibly lucky find.


The unique shape of the stalk-eyed fly (

Teleopsis quadriguttata

) is a classic example of what scientists refer to as “runaway sexual selection.” Incredibly, the red globes at the ends of those stalks are highly functional compound eyes. Over the course of millions of generations, female preference for males with widely spaced eyes has resulted in this strange and cumbersome trait.


There are dragons in the Penang Hill rainforest. This lizard, known as the armored pricklenape (

Acanthosaura armata

), has defensive spines running along the length of its back. The spines provide the lizard with a formidable defense against would-be predators and any unwary scientist wanting to take a closer look.


The quest to find new species can be painstaking—and dirty—work. Entomologists conducting this biodiversity survey of the Penang Hill rainforest spent hours slowly combing through soil at the base of towering trees and under rotting logs. Their reward? Periodically, they would encounter a rare species like this tiny, 4-millimeter-long subterranean ant (

Mystrium camillae

), as well as several species that may be entirely new to science. Only time—and careful analysis back in the lab—will tell.


Bats of many species were a common—if fleeting—sighting on Penang Hill’s forest trails at night. Along with many other individuals, this intermediate horseshoe bat (

Rhinolophus affinis

) was captured by biologists during the survey, identified, photographed, measured, and released.


Gaze into the dazzling compound eyes of this signal fly (


sp.), which are painted with psychedelic stripes of green and red. These eye patterns likely help the fly to see its surroundings in brighter definition—scientists think signal flies use the distinct bands of their eyes to perceive different colors.



While many spiders construct webs that are practically invisible, some, like this juvenile

Argiope versicolor

, weave striking geometric patterns at the web’s center. Known as stabilimentum, these structures were once thought to stabilize the web. While that idea has been debunked, scientists are still not sure what function the decorations serve. The current thinking is that they either attract prey or help the spider avoid detection by predators by breaking up the spider’s outline. Perhaps it’s both.



Wagler’s pit vipers (

Tropidolaemus wagleri

), like this juvenile perched on a tree branch, are highly venomous ambush predators. They can also practice incredible patience. One individual of the species was seen poised in the exact same spot for the entire two weeks of the Penang Hill biodiversity survey as it waited for prey to pass within striking distance.



For many ant species, defense of the colony sometimes involves the sacrifice of the individual. This species,

Camponotus saundersi

, is known to defend the colony with a particularly ghastly strategy known as autothysis, in which an ant can cause itself to essentially explode spraying the poison it contains inside on any intruder within range.



Finding frogs in the rainforest at night requires a highly tuned ear as much as a sharp eye. Scientists located this spotted river frog (

Pulchrana picturata

) first by its call and ultimately, by probing under a large rock at the edge of a stream where the tiny individual was hidden.



Colugos (

Galeopterus variegatus

), also called flying lemurs for their ability to glide from tree to tree, are some of the most unusual mammals in the Penang Hill rainforest. Being shy, nocturnal creatures, they are rarely seen. To aid them in their survey for these and other creatures, biologists used thermal cameras to detect the heat signatures from animals high in the canopy.



Every trail in the Penang Hill rainforest is full of biological surprises, if you know where to look. Here, an unusually fuzzy ant in the genus


was seen walking on a plant along the trail. This genus of ants typically lives high up in the canopy of trees, and for that reason it is rare to find and even rarer in scientific collections.



Trash line orb weavers, like this individual (


sp.), are known for camouflaging themselves amongst debris they hide in their web. But this silvery metallic species appears to camouflage itself in its spiral web decorations known as stabilimenta.



The long-tailed macaque (

Macaca fascicularis

) is well known throughout the Penang Hill rainforest—particularly along the forest’s edge, near human civilization. Infamous for their opportunistic habit of stealing food and other items from humans, these clever primates seem to as comfortable foraging in the rainforest as they are near an outdoor café.



A boulder-filled stream running down Penang Hill was perfect habitat in which to find a number of frog species at night, including this Blyth’s river frog (

Limnonectes blythii

). Still relatively common on the Malay Peninsula, the species is listed as Near Threatened worldwide due to harvesting elsewhere in Southeast Asia.



Soldier flies in the family Stratiomyidae are known to have larvae that eat decaying organic material. This soldier fly (

Eudmeta marginata

) is remarkable for its brilliant blue color—highly unusual for this group of flies made up of nearly 3,000 species.species.



Like other members of the family Salticidae, this unidentified jumping spider uses its pair of large, forward-facing eyes to locate and ambush prey.

Funding for the 2017 Penang Hill biodiversity survey, including travel expenses for Phil Torres, provided by The Habitat Foundation.


ABOUT THE Photographer

Phil Torres is a biologist, photographer, and science communicator based out of New York City. He lived for two years in the Amazon basin while working alongside research, education, and conservation projects with a focus on entomology and ecotourism. You can follow his work on Instagram and twitter: @phil_torres

Phil Torres




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