Java Island has more than 100 million people, but not enough space for a tiger

In 1602, the first multinational stock company in human history, the Dutch East India Company, was established. During the Age of Exploration in the 17th century, this initiative provided investment protection for the Dutch who wanted to make a fortune in maritime trade; the "sea coachmen" who drove flat-bottomed boats and held nautical charts established dense trade routes in the East Indies. The East India Company's Asian headquarters was set up in the key stronghold of the trade network - the port city of Batavia.

However, "Batavia" is just an old name of the Dutch. This place originally had its own traditional name, which has been used since the end of Dutch colonialism, namely Jakarta. Today, this world-famous port still stands in the northwest corner of Java Island, but the tropical rainforest behind it has been missing a sound forever - the jungle roar of the Javan tiger Panthera tigris sondaica.

Javan tiger photographed in Ujung Kulon, western Java, 1938 by Andries Hoogerwerf | Wikimedia Commons

The Land of Thousand Islands

Java Island is located in the Sunda Islands, the "Land of Ten Thousand Islands" in Southeast Asia, bordering Bali Island to the east and Sumatra Island to the west. The natural history of this area is inextricably linked to volcanoes. On the time scale of geological history, the Sunda Block, where this chain of islands is located, is at the junction of plates. The subduction of the Indo-Australian Plate to the Eurasian Plate created the two narrow islands of Sumatra and Java and other small islands on the edge of the latter, and triggered a series of volcanic activities on the island arc.

Today, Java Island is close to the equator, and it has abundant rainfall and is hot and humid all year round under the influence of the Indian Ocean monsoon. Repeated volcanic eruptions in history have left thick volcanic ash on the island. The fertile land rich in minerals provides a paradise-like growth environment for various tropical plants.

Illustration of a tiger and a Javan rhino, Rhinoceros sondaicus | Wikimedia Commons

In addition to plants, many chapters of the evolutionary history of animals in the Sunda region are also due to volcanoes, which can be described as "half sea water and half fire": with the alternation of glacial and interglacial periods, animals on the ancient land of Sunda can sometimes migrate and spread between modern islands, and sometimes be blocked by rising sea water; and the impact of volcanic eruptions may be even more extensive - more than 70,000 years ago, the Toba (bā) supervolcano on the island of Sumatra erupted, and the volcanic dust that covered the sky and the sun caused a global cooling of the climate. During the harsh climate period, forests that require water and heat retreated to fragments of unconnected regions, and animals that rely on forest habitats naturally entered these island-like "refuges", cut off contact with their counterparts in other regions, and embarked on a relatively independent evolutionary path.

Tigers in Southeast Asia

Two to three million years ago, a branch of cats evolved into tigers with unique black stripes, strong forelimbs, and good at hiding and ambushing in the jungle. Analysis of genomic information shows that the ancestors of the six subspecies of tigers we can see today can be traced back to a group of individuals about 110,000 years ago. Researchers infer that the long ice age before this time point led to the extinction of other groups, and this group of tigers began their journey from the Indochina Peninsula to conquer Southeast Asia.

Artwork honoring the Javan tiger | Vanesa Santamaria Trinidad

The tropical rainforests on the Sunda Islands are naturally a large space suitable for tigers to survive. After the Toba volcano erupted, many animal populations in Southeast Asia suffered heavy losses. The population fluctuations caused by this history are still recorded in the genome information of various species. The three tiger subspecies in the Sunda Islands that we know of - the Sumatran tiger, the Javan tiger and the Bali tiger - were precisely the ones that followed the recovery of the environment and settled on the three islands around 67,000 years ago.

A Bali tiger shot | Matti T. Heino et al. / Mammal Study (2019)

On the beautiful tropical island, the big cats have gradually adapted to the local environment. Compared with the Siberian tiger, which is three meters long and weighs more than 200 kilograms, the Javan tiger is petite, usually only a little over two meters long and weighing about 100 kilograms, which is slightly unworthy of the title of the largest cat. In 1964, biologist Foster proposed the "Island Rule", which believes that large mammals will become smaller in island habitats to adapt to the scarcity of food - at least in the evolution of the Javan tiger, this rule is valid.

In addition, the "Three Island Tigers" often appear to have a darker body color, tending towards orange, and have more and denser black stripes; this is quite similar to the blackened fur color of leopards that often appear in Southeast Asia, and may provide better concealment for the big cats in the dark forests.

Sumatran tiger, is there a darker one? | Captain Herbert / Wikimedia Commons

No Tiger in the Mountain

However, in the late 19th century, the Dutch East India Company launched agricultural reforms in Java, transforming large tracts of tropical rainforest and alluvial plains into plantations of single cash crops such as teak. The resulting decrease in prey numbers and increase in human-animal conflicts put the Javan tiger in trouble.

Hunted tiger, photographed by H. Bartels in Malingping, West Java, 1941 | tropenmuseum

A web of roads emerged on Java and Bali, fragmenting the tiger's habitat into smaller pieces. In the 1920s and 1930s, a series of protected areas were established in Java, while in Bali, the Dutch continued to target Bali tigers for hunting. In the 1940s, the Bali tiger became extinct. In the 1970s, Javan tigers were only found in the Meru-Betiri area in the southeast corner of Java. In 1976, researchers were able to count at least three tigers; in the 1980s, people had to admit that the Javan tiger was also extinct.

Illustration of the 1980 WWF report on Javan tiger conservation. The diagonal shading is the distribution area of ​​Javan tigers around 1940, and the black (small black dot in the southeast corner) is Meru-Betiri | Seidensticker et al, 1980.

Today, Java is home to nearly 150 million people. In terms of area, Java is the 13th largest island in the world, but in terms of population, it is the largest island in the world. Yes, the most populous island in the world is not Australia or Honshu, Japan, but this tropical volcanic island that was once home to Javan tigers. As a production base for important cash crops such as oil palm and a habitat for rare animals such as orangutans, the pearl-like Sunda Islands still face a severe wildlife protection situation. How to achieve harmonious coexistence between man and nature is still a problem that our generation has to face.

Javan tiger skeleton specimen at the Finnish Museum of Natural History | Matti T. Heino et al. / Mammal Study (2019)

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