The first adult female death of a Kakapo occurred a few weeks ago when Sarah was found dead on Codfish Island. The Kakapo Recovery Programme website has the details, with the story spotted by Twitterer @bekibutton.

We are unsure of the cause of death; autopsy revealed that she was in good condition and that her death had been sudden.

The bacteria Clostridia perfringens was cultured from samples collected at autopsy, but it is not known whether this bacteria was related to her cause of death, or simply a post death overgrowth (she had been dead for one or two days before discovery).
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Sarah’s passing reminds us of how rare and precious the kakapo are; taking the world kakapo population to 122. Rest in peace Sarah, we will miss you.