Bramble Cay melomys

The Bramble Cay melomys, also called the Bramble Cay mosaic-tailed rat, was a special kind of rodent that lived only on Bramble Cay. This tiny island, just about 5 acres big, sat at the northern tip of the Great Barrier Reef in Australia. The rat belonged to a family of animals called Muridae and was part of a smaller group known as Murinae.

Scientists last saw this rat in 2009. By 2016, the Queensland Government and researchers from the University of Queensland said the rat was gone forever. In 2015, a group called the International Union for Conservation of Nature officially said the rat was extinct, and the Australian government agreed in 2019.

What made this rat very important was that it was the only animal that lived only on the Great Barrier Reef. Sadly, its disappearance was thought to be the first time a mammal went extinct because of changes people made to the Earth, like climate change. This helped people understand how important it is to protect animals and their homes.

Taxonomy

The Bramble Cay melomys was a type of rat that belonged to the group of animals called Melomys. This group has about 20 different kinds of rats that live in wet places in northern Australia (Far North Queensland), New Guinea, the Torres Strait Islands, and islands in the Indonesian archipelago. These rats are part of a bigger family of small animals called Muridae.

People first found the Bramble Cay melomys in April 1845 on an island called Bramble Cay. This island is a small, sandy place covered in plants, located at the northern tip of the Great Barrier Reef. Back then, there were so many of these rats that sailors on a ship even used bows and arrows to shoot them for fun. Later, scientists collected one of these rats and kept it in a museum in Britain. In 1924, a scientist named Oldfield Thomas officially named the species Melomys rubicola. Studies show that this rat is most closely related to another rat called the Cape York melomys.

Description

The Bramble Cay melomys, also called the Bramble Cay mosaic-tailed rat, was a fairly big rodent. Its body was about 14.8 to 16.5 centimeters long (roughly 6 inches), and its tail was 14.5 to 18.5 centimeters long (about 5.75 to 7.25 inches). It had a long tail, short ears, and large feet. It weighed between 78 and 164 grams (about 2.75 to 5.75 ounces). The tail could grab things at the tip and had rough scales. Its fur was reddish brown on top and greyish brown on the bottom, with black hairs on its back. It looked similar to the Cape York melomys, a close relative. Like other melomys rats, it had a Roman nose.

Distribution and ecology

Scientists are not sure how the Bramble Cay melomys reached its home on Bramble Cay. Some believe it may have swum there on driftwood from the island of New Guinea. Others think it was there when Australia was once connected to New Guinea by land, and stayed behind when the lands separated.

This rodent lived on Bramble Cay, a tiny island in the northeastern part of the Torres Strait. The island is about 50 kilometres (31 miles) from the Fly River in Papua New Guinea. Though the whole island is only about 4 to 5 hectares (which is about 10 to 12 acres), the melomys lived only in the vegetated part, which was around 2 hectares (5 acres) in size. The island had short grasses and herbs, usually less than half a metre tall.

The island had very few types of plants at any one time, though scientists have found records of 11 different plants over the years. Some common plants included Portulaca oleracea, Boerhavia albiflora, Cenchrus echinatus, and Amaranthus viridis. The island also had many seabirds and was sometimes disturbed by green turtle breeding. The melomys liked areas with thicker plants and stayed away from places with lots of seabirds. It ate plants like P. oleracea and sometimes turtle eggs.

The number of these rodents changed over time. In the past, people thought there were "hundreds" of them. In 1998, scientists caught 42 and guessed there were about 90 in total. Later surveys in 2002 and 2004 found only 10 or 12, and estimates suggested there were fewer than 50 or even under 100 left.

Status and conservation

The Bramble Cay melomys lived on a small island that was at risk because of severe weather and rising sea levels. In 2008, the Queensland Government's Environmental Protection Agency created a plan to help protect the animal. The last time anyone saw this rodent was in 2009, and searches in later years did not find any.

In 2016, scientists from Queensland's Department of Environment and Heritage Protection and the University of Queensland announced that the species was extinct. They believed that changes in the climate were a big reason for this. The International Union for Conservation of Nature also listed it as extinct in 2016. The Australian Government’s Department of the Environment and Energy officially recognized this in February 2019. The main reason for the extinction was likely the island getting flooded often, which destroyed the animal’s home.

Commentary on extinction

Scientists believe the Bramble Cay melomys, a special kind of rat, disappeared from its home on Bramble Cay between 2009 and 2011. The main reason for this was the loss of its home because the island got smaller due to erosion. Strong weather events made things worse by destroying places where the rats could hide.

Experts said this might be the first time a mammal went extinct because of changes caused by humans to the climate. They think the root cause was rising sea levels due to global warming. Some believe the species could have been saved with better conservation efforts. Sadly, the island’s small size and lack of attention made it hard to protect the rats.

Possible survival

The scientists who studied the extinction said it’s possible the Bramble Cay melomys might still exist somewhere else, like in the Torres Strait islands or on the New Guinea mainland. There were old reports of similar rats from another island, but these were likely different. Some stories told of rats floating on debris, but no one has found proof of them living outside Bramble Cay. Until more searches are done in places like the Fly River delta in New Guinea, we can’t say for sure that they’re completely gone.

In popular culture

First Dog on the Moon made a cartoon in 2019 to honor the Bramble Cay melomys, calling it "A moment of silence for the Bramble Cay melomys, another victim of climate change."

In 2021, artists from Erub Island created sculptures named Maizab Kaur Mukeis using ghost nets. These nets are old fishing nets that hurt marine life. The artists wanted to show how these nets damage nature. Their work was chosen as a finalist for the National Aboriginal and Torres Strait Islander Art Awards.

Diet

Little is known about what the Bramble Cay melomys ate, but it is believed they mainly ate plants like leaves, seeds, fruits, and flowers. These rats were good climbers and often moved through rainforest trees to find food. They were an important food source for animals such as sooty owls and pythons. Their diet likely included plant material, insects, and maybe even bird eggs. This ability to find food in a small home showed how tough these rats were.