From a farming background in Co. Waterford, Brendan has spent over 20 years living and working in the Burren region. In 2001 he completed his doctorate on the impact of farming on the heritage of the Burren, later published by Teagasc as 'Farming and the Burren'. He led the award-winning BurrenLIFE Project (2005-10), its successor, the pioneering ‘Burren Farming for Conservation Programme’ (2010-15) and currently manages the new ‘Burren Programme’.

Along with his late wife Ann O’Connor, Brendan co-founded Burrenbeo Teo and is secretary of its successor, the Burrenbeo Trust which aims to ‘connect all of us to our places and our role in caring for them’ and co-ordinates events such as the Burren Winterage festival and the Learning Landscape Symposium. Brendan is also a founder of the ‘Farming for Nature’ initiative which aims to acknowledge and support farmers across Ireland who want to protect our natural heritage.
Brendan is a former board member of the Heritage Council, a former member of the EPA Advisory Committee and a former Director of the European Forum on Nature Conservation and Pastoralism. He is an Ashoka Fellow for Ireland since 2011 and in 2018 he was awarded an Honorary Doctorate by NUI Galway for his work in championing biodiversity.