Re-introduction of stinking hawk’s-beard into South-East England, UK

Summary

Stinking hawk's-beard (Crepis foetida foetida), listed Extinct in the UK after its last wild record in 1980 at Dungeness, Kent, was the subject of an RSPB-led reintroduction beginning in 1992 using seed germinated from herbarium material, becoming a UK Biodiversity Action Plan priority species by 1998. Early experimental plantings at Dungeness's original shingle site and, from 2000, at Rye Harbour in East Sussex initially grew and then collapsed to zero by around 2001 and after four years respectively, attributed to vegetation succession after historic grazing and disturbance ceased. Genetics testing at the Royal Botanic Garden Edinburgh found no evidence that a genetic bottleneck in UK stock explained these failures. Introductions to three North Kent chalk pits in 2003 also went extinct by 2007, but a parallel planting in a private gravel garden at Northiam boomed to over 1,800 plants by 2011, dispersing up to 105 meters and colonizing bare clay, limestone and flint scree. Fencing installed at Rye Harbour in 2005 to protect another rare plant incidentally excluded rabbits, after which the local hawk's-beard population grew almost exponentially into an apparently self-sustaining group. Seedling mortality across sites regularly exceeded 50%, driven by slug and snail grazing and late-spring drought, while rabbit exclusion increased flower-head production more than elevenfold. A possible remnant wild population was found at Dungeness in 2010. The project rates itself Partially Successful, reflecting repeated site failures alongside eventual self-sustaining populations at Rye and Northiam.