Climate change threatens Komodo dragons

Komodo dragon

A Komodo dragon (Image: Achmad Ariefiandy / Komodo Survival Program)

The Komodo dragon – the world’s largest lizard – is already endangered today. Climate change could even cause the lizards to become extinct in the future. According to forecasts, rising temperatures and rising sea levels will greatly change the habitats of these rare animals. In order to ensure the survival of the Komodo dragons, protective measures would have to be taken shortly.

The last dragon of our time: the Komodo dragon, Varanus komodoensis, has inhabited the earth for more than a million years. And although he is a successful predator with his stamina, enormous strength and razor sharp teeth, it is estimated that only 4,000 individuals live in the wild today. The famous lizards are only native to five southeastern Indonesian islands: Komodo, Rinca, Nusa Kode and Gili Motang, all of which are part of the Komodo National Park, as well as Flores.

Indonesia will heat up

For 20 years, scientists have been watching with concern the falling numbers of the rare Komodo dragons in Indonesia. This gave a research team led by Alice Jones from the University of Adelaide the impetus to investigate the possible influence of climate change on the famous lizards. According to models, the impending changes will have a particularly strong impact on tropical islands. “For Indonesia, the forecasts predict an unprecedented increase in temperatures and a decrease in precipitation,” the researchers report. “This will lead to an extended dry season with more fires and increased dryness of the ground.”

In order to determine the possible effects on the Komodo dragons, Jones and her team used an ensemble of climate models to recreate six scenarios of future development and their consequences for the animals’ habitats. Depending on the scenario, there were different degrees of sea level and temperature rises, as well as climate-related changes in the vegetation for the Indonesian islands. The researchers supplemented these scenarios with an ecological model that included the requirements of the monitor lizards in terms of their habitat and the availability of prey, as well as their preferred whereabouts. They also took into account the population structure of the lizards and their development.

Habitats and populations are shrinking

The result: “Climate change is likely to lead to a sharp decrease in the availability of habitat for Komodo dragons,” says Jones. According to the models, the Komodo dragons’ habitat could shrink by up to 92 percent by 2050. The flat, dry lowlands near the coast, preferred by Komodo dragons, would be particularly affected. Warming open forests could turn these habitats into arid savannah. “Such a change could make these lowland habitats unsuitable for the Komodo dragons within the next three decades,” the researchers report. Some coastal areas would also be flooded by rising sea levels.

This would have significant consequences for the Komodo dragons: “This will greatly reduce their populations within a few decades,” says Jones. According to the forecasts, the Komodo dragon population in the entire range of the species could decline by 30 to 99 percent, depending on the climate scenario. “Our models predict local extinction on three of the five islands where Komodo dragons can be found today,” says Jones colleague Damien Fordham. “Even if we treat all resources equally, things look bleak for the small populations on Kode and Montang.” On the other hand, on the two larger protected islands of Rinca and Komodo, the lizards are less endangered because more monitor lizards live there and they have more opportunities to escape.

This is different on the larger island of Flores. This island is not a protected area and therefore the Komodo dragons are also endangered due to illegal hunting, forest clearing for agricultural land and the expansion of housing developments. This population could also become extinct if climate change continues unchecked. “The severity and extent of human actions affecting Komodo dragon populations, particularly on Flores Island, are only just being realized,” says Deni Purwandana of the Komodo Survial Program in Bali. On the other islands, which belong to the Komodo National Park, the lizards are actively protected and have more places of refuge.

Now the human being is required

These findings also provide valuable information on the conservation of the rare Komodo dragons. “Insight into the future effects of climate change offers new opportunities to work with conservation agencies and local communities to find local solutions that limit the climate and other threats to Komodo dragons and their habitats,” said Jones colleague Tim Jessop.

“Projects like the establishment of new reserves in areas that are supposed to preserve high-quality habitats in the future despite global warming could help reduce the effects of climate change on Komodo dragons,” explains Jones. “Conservationists may need to consider relocating animals to locations in the coming decades where Komodo dragons have not been found for many decades. This scenario can easily be tested with our approach. “

Source: University of Adelaide; Technical article: Ecology and Environment, doi: /10.1002/ece3.6705

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