Barry Trevis has worked voluntarily at the Herts and Middlesex Wildlife Trust's Lemsford Springs reserve since 1977 and has been its honorary warden since 1981. During those 40 years he has organised and supervised more than 500 work-parties and community events there and collaborated in a scientifically valuable project on the Green Sandpipers Tringa ochropus that migrate to the reserve each winter. As past 1875 Award-winner Peter Oakenfull, observed when making the presentation to Barry: "For most people who know the reserve, he is Lemsford Springs"

His colour-ringing of Green Sandpipers at Lemsford Springs with Ken Smith, Mike Reed and others, started in 1983 and is now the longest running project of its kind on waders in Europe. More than  200 individuals have been ringed and three scientific papers (on site fidelity, feeding behaviour and requirements, and the use of geolocator harnesses) have been published. The more recent use of GPS geolocation technology has made it possible to use tagged birds to establish migration routes and breeding sites.  Ten tags have been recovered to date, and a further research paper is being planned. 

However, Barry's ringing activities have not been limited to one species. He was the first to ring Little Egret Egretta garzetta in 2003 as it reached Hertfordshire as a breeding species, and likewise Red Kite Milvus milvus. He remains actively involved in the colour-ringing of Little Egrets at Verulamium Lake, St Albans and Stanborough Lake, Welwyn Garden city,  where 71 pulli and full-grown birds have been ringed to date. He has been responsible for heronry census surveys at three sites since 1987.

More widely, he has assisted with ringing projects around the British coastline, across Europe and in South Africa and Tanzania. He is also an enthusiastic trainer of new 'ringers', while assessing more expert ones for permit advancement.

For more than a decade, his further contributions to conservation have included the building and provision of nestboxes for Barn Owl Tyto alba, Tawny Owl Strix aluco and Kestrel Falco tinnunculus in mid-Herts as well as regular monitoring and ringing of these species.

In professional life, Barry was  Welwyn Hatfield District's Environmental Strategy Officer from 1990 to 2000. He initiated local conservation and public engagement projects while developing the council's environmental policies, including publication of the first nature conservation strategy for a Herts. local authority.  He is also a past Chairman of the Herts Bird Club (1986-7) and former writer of the 'waders' section for the Herts Bird Report.