1. Headline suggests an answer
2. Content of article delivers the actual answer
3. There are even links provided to previous articles showing that this had been a bona fide mystery until recently
Clickbait is stuff like a youtube video titled "OMG Car market just flipped!" and it's a 15 minute video where a podcaster gets told by his dad various reasons to believe the car market hasn't really flipped yet.
2. Content of article delivers the actual answer"
that's literally the definition of click bait .... They bait you into clicking to get the answer
They could have instead changed the title to include the answer
"Scientists discover the death of dozens of endangered elephants was due to blood poisoning"
But then no one would click, bc most people wouldn't care to learn more. And then the Guardian wouldn't get its sweet sweet ad revenue