Heidi_70

Your instinct isn't wrong - predators are the classic island story. In the 32 extinct species I've documented the causes come out: hunting and collecting 10, introduced disease 9, habitat loss 6, introduced predators 5.

What surprised me is how cleanly disease sorts by place. All nine disease cases are Hawaiian, and all nine Hawaiian species are disease cases. One-to-one, no overlap in either direction.

Rats and cats show up hardest in the flightless birds, and they got there early. The flightless species in the set have a median last record of 1662, against 1946 for the ones that could fly - and nothing flightless has a last record after 1899.

The Wolbachia work is further along than most people realise: drone delivery on Maui from April 2025, past 40 million males released by mid-2025.

Fair - 8 of 13 are Hawaiian. Though the birds that could leave are precisely the ones that never arrived... and the mosquito that finished them off turned up by ship in 1826, which rather settles who had the mobility advantage ;)

The behavioural-or-physical question has one really well documented answer: The Chatham Island black robin. Down to five birds in 1980, one fertile female, and every bird alive descends from her.

Some females laid on the nest rim and lost the egg, whichEveryone assumed was a learned habit... a 2013 pedigree study found it was a dominant allele from one of the founders!

That managers rescuing the eggs is what let it spread. So not a new subspecies, but a genetic sliver of what used to exist -- carrying whatever the founders happened to carry.

On Queensland — the paradise parrot is the only extinct mainland Australian bird, last seen around Gayndah in 1927–28. The only photos of a live one were taken by a grazier from a hide made of old bagging in 1922.

I run the site, so flagging that up front.

Method, since the number deserves scrutiny: the dataset is every bird on my site where both dates are documented, the last confirmed record (specimen, photo, recording, accepted sighting, or death of the last captive) and the first formal extinction declaration by a recognised authority. That gives 13 species and subspecies. Median gap 36 years, mean 47.5, range 3 to 124.

Two rules matter for reading it. Where a bird was declared twice (IUCN and later the US delisting in October 2023), the earlier declaration counts; using the US dates would inflate most figures. And the sample is small and weighted toward Hawai'i, so the median describes these birds, not a published constant.

The pattern that seemed most robust to me: the three short gaps are all birds whose last individual was watched dying, e.g. the dusky seaside sparrow in captivity in 1987, declared in 1990. Where the record just stops, nobody can date the stopping, and the declaration takes decades.

Happy to go into the sources or any individual case.