The tragic stories behind 15 animals that went extinct

With scientists reporting that a sixth mass extinction is underway, it's more important than ever to pay attention to the impact we have on the environment.

Keep scrolling to read about 15 animals that tragically went extinct, from a treefrog named Toughie to Martha, the world's last passenger pigeon. 

The Bramble Cay melomys, a small rodent native to the Great Barrier Reef, is considered to be the first mammal species wiped out by climate change.

Also known as the mosaic-tailed rat, the Bramble Cay melomys was endemic to a coral cay— a type of small, low island — off the coast of Queensland, Australia. 

Last seen in 2009 and declared extinct in 2014, the rodent had the distinction of being the sole mammal native to the Great Barrier Reef. Researchers at the University of Queensland concluded that the species met its demise due to rising sea levels that destroyed its habitat. 

The world's last Rabbs' fringe-limbed treefrog, a male named Toughie, died in 2016.

Technically critically endangered, the Rabbs' fringe-limbed treefrog hasn't been seen in the wild since 2007 — two years after scientists discovered the species in Panama, where the population had already been ravaged by deadly chytrid fungus. 

Toughie, the last known member of his species, died in 2016 at the Atlanta Botanical Garden. Since he was already an adult when researchers found him, his age was unknown. He and another male were brought back to the US at the same time, but his fellow amphibian was euthanized in 2012. 

Nicknamed the "loneliest frog in the world," Toughie — who was famous enough to have his own Wikipedia page— became a symbol of the frog extinction crisis. 

According to folklore, a lighthouse keeper's cat named Tibbles was responsible for wiping out most of the Stephens Island wren population.

We may think cats are cute and cuddly, but our feline friends have been detrimental to local populations of birds and other small animals for decades, killing millions each year. According to a 2013 study published in Nature Communications, free-ranging cats are "likely the single greatest source of anthropogenic mortality for US birds and mammals." 

Due to land development and predation by cats introduced to the area, the Stephens Island wren, a bird native to New Zealand, was extinct by 1895. According to folklore, a lighthouse keeper's cat named Tibbles enjoyed preying on the birds and wiped out a significant percentage of the species.

However, a report by the Ornithological Society of New Zealand suggests he likely he didn't act alone.