The death has taken place of wildlife film-maker and former senator Éamon de Buitléar.
Mr de Buitléar, who was 83, died at his home in Delgany, Co Wicklow, last night.
He was Ireland's best known independent wildlife film-maker since the 1960s.
He was also known for promoting the Irish language and traditional music.
A founder member of Seán Ó Riada's Ceoltóirí Chualann, Mr de Buitléar was an accomplished musician, playing the mouth organ and button accordion.
He was also the author of several books, including schoolbooks on Ireland's natural history and a recent memoir, A Life in the Wild.
He was appointed to Seanad Éireann in 1987 in recognition of his work with environmental issues and to the Heritage Council and the Central Fisheries Board.
In November last year, Mr de Buitléar donated his entire archive of film, music and writings to the National University of Ireland, Galway.
He is survived by his wife, Lailli, and five children, Aoife, Éanna, Róisín, Cian and Doireann, grandchildren, great-grandchildren, sisters and brothers.
Speaking on RTÉ's Morning Ireland, broadcaster and botanist Éanna Ní Lamhna paid tribute to Mr de Buitléar.
She said: "He was in and out of our programme occasionally and of course he wasn't just a man with a film, he could actually speak about wildlife on a radio programme and produce wonderful word pictures.
"You could see what he was talking about and then he would whip out his mouth organ and give us a little tune."
RTÉ Director General Noel Curran said programmes like Amuigh Faoin Spéir, Ireland's first wildlife series, had a profound influence on attitudes to our environment.
He said: "In November 2012, Éamon donated his entire collection of film, music and writings to the National University of Ireland, Galway, and RTÉ was delighted to partner with NUIG to preserve the programme collection.
"It is fitting that the work of one of Ireland's most unique film-makers should be preserved in this way, in tribute to Éamon de Buitléar's outstanding contribution to education, to film-making, and to Irish life."