Artist in oil, alkyd and red crayon, born in London, who specialised in depicting birds of prey. Having always painted and drawn, in late 1940s Treleaven met the bird painter George Lodge, joined the British Falconers’ Club, served on its committee and obtained live hawks for models. In the early 1970s Treleaven met the painter Alexander Mackenzie, having settled in Launceston, Cornwall, which broadened the scope of his pictures. In 1977 Treleaven published Peregrine; wrote for specialist publications on the falcon and was acknowledged as an authority. Showed with Contemporary Bird Painters Exhibition at Reading, with Sporting and Wildlife Paintings, Moorland Galleries and AEB. Was a founder-member of SWLA and British Ornithologists’ Union.