The Norfolk hawker Aeshna isosceles is an extremely rare dragonfly, one of two species of brown hawkers in Britain. It has a yellow triangular mark on the second abdominal segment which gave rise to its scientific name. It also has green eyes and clear, untinted wings. It is mainly a Mediterranean species, at home in the lowlands of North Africa and Southern Europe.

In Britain, the Norfolk hawker is protected under Schedule 5 of the Wildlife and Countryside Act 1981, and listed in Category 1 (endangered) in the British Red Data Books on Insects.

Its habitats in The Broads National Park in Norfolk, England are mainly Hickling Broad and two National Nature Reserves: Mid-Yare NNR and Ludham - Potter Heigham NNR.

The Norfolk hawker needs unspoilt grazing marsh dykes, clean non-saline water, rushy margins, and lots of aquatic plants, especially Water soldier Stratoides aloides.

See also: Endangered species, Extinction