This has posted, and discussed, to HN in the past. From the article: "According to the team, firehawk raptors congregate in hundreds along burning fire fronts,

This has posted, and discussed, to HN in the past. From the article: "According to the team, firehawk raptors congregate in hundreds along burning fire fronts, where they will fly into active fires to pick up smouldering sticks, transporting them up to a kilometre (0.6 miles) away to regions the flames have not yet scorched." ... where "according to the team" means "we have not actually filmed or photographed this behaviour, once, despite years of trying". I wish them the best of luck; it would be fascinating to learn of animals other than humans using fire as a tool. But for now, it's still firmly in the "old bush legend" category.