Yet it was not the interloping humans Rattus macleari needed to worry about as much as the European black rats they brought with them to the Australian territory, which were carrying deadly parasites.
By 1903, the Christmas Island rat was no more.
That is, until now.
Tom Gilbert, an evolutionary geneticist at Denmark's University of Copenhagen, believes Maclear's rat - to use its more common name - is the closest thing he has seen to a genuine de-extinction candidate.
Minus perhaps the odd anatomical characteristic or two, he thinks he can bring it back to life.
Popularised in the 1990s, de-extinction efforts have thus far focused on pseudo-mythical giants like the woolly mammoth which died out 4000 years ago.
In Melbourne, scientists hopeful at some stage of reintroducing to the wild Australia's most famous lost species, the Tasmanian tiger, are building a $5 million genetic restoration lab.
However Professor Gilbert and his team of paleogeneticists have turned their attention to Rattus macleari's 119-year absence as a test case for the revival of extinct species generally - not to mention the ethical dilemma of tampering with nature.
So far, the results have been challenging but encouraging.
When sequencing the genome of extinct species, scientists are forced to work with degraded DNA, which yields an incomplete information set.
With the Christmas Island rat, though, Prof Gilbert and his colleagues got lucky.
Not only have they successfully obtained nearly all the rodent's genome but since it diverged from other Rattus species fairly recently, it shares about 95 per cent of its make-up with a living rat, the Norway brown.
"It's the perfect case because when you sequence the genome you have to compare it to a really good modern reference," Prof Gilbert said.
Once this process is taken as far as it can be, gene-editing technology will be used to match the outstanding DNA of the living species to that of the extinct one.
The brown-rat-to-Christmas-Island-rat scenario works because their evolutionary divergence is mild.
Though the sequencing of Rattus macleari was mostly successful, Prof Gilbert said a few key olfactory genes were missing, meaning if resurrected it would probably be unable to process smells the way it would have originally.
"It is very, very clear that we are never going to be able to get all the information to create a perfect recovered form of an extinct species," he says.
Or as Bob Dylan once famously put it: "You can always come back but you can't come back all the way".
Even so, it may be possible to make an ecologically functional mammoth, for example, by editing elephant DNA to make the animal hairy enough to survive the cold.
"If you're making a weird fuzzy elephant to live in a zoo, it probably doesn't matter if it is missing some behavioural genes," Prof Gilbert said.
"But that brings up a whole lot of ethical questions."
