Attenborough is widely considered a national treasure in Britain, although he himself does not like the term. In 2002 he was named among the 100 Greatest Britons following a UK-wide poll for the BBC. He is the younger brother of the director, producer and actor Richard Attenborough, and older brother of the motor executive John Attenborough.
Attenborough was born in Isleworth, Middlesex (now part of west London), but grew up in College House on the campus of the University College, Leicester, where his father, Frederick, was principal. He is the middle of three sons (his elder brother, Richard, became an actor and director and his younger brother, John, was an executive at Italian car manufacturer Alfa Romeo), and the only surviving child among them. During World War II, through a British volunteer network known as the Refugee Children's Movement, his parents also fostered two Jewish refugee girls from Europe.
Attenborough spent his childhood collecting fossils, stones and other natural specimens. He received encouragement in this pursuit at age seven, when a young Jacquetta Hawkes admired his "museum". He also spent a considerable amount of his time in the grounds of the university, and, aged 11, he heard that the zoology department needed a large supply of newts, which he offered via his father to supply for 3d each. The source, which wasn't revealed at the time, was a pond less than five metres from the department. A few years later, one of his adoptive sisters gave him a piece of amber filled with prehistoric creatures; some 50 years later, it would be the focus of his programme The Amber Time Machine.
In 1936 David and his brother Richard attended a lecture by Grey Owl (Archibald Belaney) at De Montfort Hall, Leicester, and were influenced by his advocacy of conservation. According to Richard, David was "bowled over by the man's determination to save the beaver, by his profound knowledge of the flora and fauna of the Canadian wilderness and by his warnings of ecological disaster should the delicate balance between them be destroyed. The idea that mankind was endangering nature by recklessly despoiling and plundering its riches was unheard of at the time, but it is one that has remained part of Dave's own credo to this day." In 1999, Richard directed a biopic of Belaney entitled Grey Owl.
Attenborough was educated at Wyggeston Grammar School for Boys in Leicester and then won a scholarship to Clare College, Cambridge in 1945, where he studied geology and zoology and obtained a degree in natural sciences. In 1947 he was called up for national service in the Royal Navy and spent two years stationed in North Wales and the Firth of Forth.