The last wild Fiji petral specimen collected, an albatross-like bird (as petrels tend to be) that spends much of its time over the open sea, was collected in 1855 fro Gau Island, Fiji.
It didn’t really go extinct, because in 1984 one was caught on Gua, photographed, and set free. Subsequently, possible Fiji petrel sightings have occurred now and then, mostly of disoriented or lost immature birds that showed up in one village or another.
So, as you can see, calling this bird truly extinct was never really appropriate, but it was listed as one of nearly 200 birds that may or may not have been extinct at any given moment, with a very small hope returning every now and then wiht a possible or confirmed sighting. But then scientists went out and got serious bout finding some Fiji petrels and assessing their status.
They did this by setting up a lure consisting of 10 kilogram blocks of fish guts mixed with concentrated fish oil. This substance can be smelled by a petrel from half way around the planet. Well, not really but from very far away. Sure enough, on day two of the experiment, a Fiji petrel showed up to inspect one of the blocks which was floating around int he water. Over the next eleven days eight different individuals were observed.
The story is reported here.