Question: What is the birthdate of the man that is being succeeded by Stuart Chambers?

full_context: Document 1: Mark Cutifani: Mark Cutifani (born 2 May 1958) is an Australian businessman and the current chief executive of diversified mining group, Anglo American plc. He was formerly CEO of South African gold mining company AngloGold Ashanti, a position he held from October 2007 until March 2013.
Document 2: Charles Dunstone: Sir Charles William Dunstone, CVO (born 21 November 1964) is the co-founder and former chairman of mobile phone retailer Carphone Warehouse, former chairman of multinational electrical and telecommunications retailer and services company Dixons Carphone (formed on 7 August 2014 by the merger of Dixons Retail and Carphone Warehouse), and executive chairman of the TalkTalk Group.
Document 3: Martin Broughton: Sir Martin Faulkner Broughton (born 15 April 1947) is a British businessman and Deputy Chairman of International Airlines Group. Formed in January 2011, IAG is the parent company of British Airways, Iberia and Vueling. It is a Spanish registered company with shares traded on the London Stock Exchange and Spanish Stock Exchanges. The corporate head office for IAG is in London, UK.. He is also a managing partner at Sports Investment Partners. He is a former chairman of Liverpool Football Club and also served as President of the Confederation of British Industry.
Document 4: Warren East: (David) Warren Arthur East {'1': ", '2': ", '3': ", '4': "} (born 27 October 1961) is the chief executive officer (CEO) of Rolls-Royce Holdings, a leading UK-based engine manufacturer. He previously held senior positions at ARM Holdings and Texas Instruments.
Document 5: Jim Pattison: James Allen Pattison, OC, OBC (born October 1, 1928) is a Canadian business magnate, investor and philanthropist. He is based in Vancouver where he holds the position of Chief Executive Officer, Chairman and sole owner of the Jim Pattison Group, the second largest privately held company in Canada. He is considered Canada's fourth richest person.
Document 6: Stuart Chambers: Stuart Chambers (born 14 September 1937 in Auckland) is a New Zealand ornithologist. He has been associated with ornithologists Charles Fleming, A. H. Hooper, Ross McKenzie and R.B. Sibson. He is the author of ""Birds Of New Zealand - Locality Guide"" and ""New Zealand Birds – An Identification Guide"". He has been involved with the Miranda Naturalists' Trust as well as the development of the Miranda Shorebird Centre, the Aroha Island Ecological Centre, and is a proponent of the development of birdwatching in New Zealand. Chambers is also the owner and manager of the small, New Zealand based, publishing company, Arun Books.
Document 7: Anglo American plc: Anglo American plc is a multinational mining company based in Johannesburg, South Africa and London, United Kingdom. It is the world's largest producer of platinum, with around 40% of world output, as well as being a major producer of diamonds, copper, nickel, iron ore and metallurgical and thermal coal. The company has operations in Africa, Asia, Australasia, Europe, North America and South America.
Document 8: David Sheepshanks: David Richard Sheepshanks CBE DL is the founding and current Chairman of the St George's Park National Football Centre and former Chairman of Ipswich Town FC. He is also chairman of UK Community Foundations (UKCF), the umbrella organisation for all community foundations in the UK, providing philanthropic advice to clients and delivering UK-wide grant-making programmes. Other business interests include non Executive roles with Coutts Bank, 21st Club and Onside Law. Past business interests included Starfish Ltd 1980-1990 and Suffolk Foods Ltd which he founded in 1990 with his brother Rick and where he was Chairman and a majority shareholder before selling in 2004. He also served externally on various local radio station Boards including Chairman of VIBE FM in 1990 and Director of Radio Orwell and BBC Radio Suffolk Advisory Board.
Document 9: Anthony Habgood: Anthony John Habgood (born 8 November 1946) is a British businessman. He has been chief executive of Bunzl and chairman of Whitbread, RELX Group and of the Court of the Bank of England. He has been described in the FT as "the City’s go-to grandee."
Document 10: John Robert Porter: John Robert Porter (born 5 January 1953) is an English billionaire businessman and philanthropist best known as the grandson of Sir Jack Cohen founder of Tesco and son of Dame Shirley Porter.
Document 11: Pearson PLC: Pearson PLC is a British multinational publishing and education company headquartered in London. It was founded as a construction business in the 1840s. It shut down its construction activities in the 1920s and switched to publishing. It is the largest education company and the largest book publisher in the world. Pearson has a primary listing on the London Stock Exchange and is a constituent of the FTSE 100 Index. It has a secondary listing on the New York Stock Exchange in the form of American Depository Receipts.
Document 12: Stuart Chambers (businessman): Stuart John Chambers (born May 1956) is a British businessman, the chairman of Rexam and ARM Holdings. He will succeed Sir John Parker as chairman of Anglo American plc from 1 November 2017.
Document 13: Mark Moody-Stuart: Sir Mark Moody-Stuart KCMG (born 15 September 1940) is a British businessman, He was appointed non-executive chairman of Anglo American PLC in 2001, serving until 2009. He has been chairman of Hermes Equity Ownership Services since 2009.
Document 14: Daily Mail and General Trust: Daily Mail and General Trust plc is a British media company, the owner of The "Daily Mail" and several other titles. The company manages a multinational portfolio of companies, with total revenues of almost £2 billion, that provide a diverse range of businesses and consumers with information, analysis, insight, news and entertainment. The company operates in over 40 countries through its subsidiaries RMS, dmg information, dmg events, Euromoney Institutional Investor, dmg media and JVs and Associates. It is listed on the London Stock Exchange. Jonathan Harmsworth, 4th Viscount Rothermere, is the chairman and controlling shareholder of the company. The head office is located in Northcliffe House in Kensington, London.
Document 15: John Parker (businessman): Sir Thomas John Parker, {'1': ", '2': ", '3': ", '4': "} (born 8 April 1942) is a British businessman. He is currently Chairman of Anglo American PLC (until 31 October 2017) and Ombu Group, and a Director of Airbus and Carnival Corporation & plc. He is also past President of the Royal Academy of Engineering, patron at the Centre for Process Innovation and a Visiting Fellow of the University of Oxford. Sir John has chaired five FTSE 100 companies, including National Grid plc, from which he stood down in December 2011. He was born into a farming family in County Down, Northern Ireland.
ground_truth: 8 April 1942