[4] It was also picked as "the very best natural history book I have read this year" by the ornithologist and writer Mark Avery,[5] described as a "truly marvellous... love letter to the butterfly" by Sophia Waugh in The Telegraph,[6] and praised by Caroline Morley, in New Scientist, for its "charming but old-school lyricism".
[7] In The Independent, Marren's 2012 book Mushrooms earned praise for its "quite staggering knowledge" and "quirky, trenchantly observant, sometimes hilarious" writing.
[8] Bugs Britannica (2010), a definitive survey of British invertebrates edited by Richard Mabey,[9] earned Marren a Leverhulme Research Fellowship in 2008.
Marren has been a regular contributor to national "broadsheet" newspapers since the 1990s, including The Daily Telegraph (for which he has been a long-standing nature columnist), The Times, The Independent,[15] and The Guardian.
[16] He has written numerous obituaries of botanists, conservationists, and naturalists, including Oliver Rackham,[17] David Bellamy,[18] Hugh Synge,[19] and Eva Crane.
[26] He has also written reports for The Battlefields Trust, including, in 1995, a detailed account of the Battle of Tewkesbury for a public inquiry into a proposed housing development.
[27] In 2006, in Natural England's first year, Marren warned in an Independent article that the organization was "already under siege" with a huge funding shortfall, plummeting morale, and "mutterings about the new management culture".
[29] Reprising the theme in 2011, he argued in The Independent that Natural England had fallen short of expectations: "With next to no public debate, our wildlife watchdog has morphed into a pathetic delivery boy, charged with attending to "customer focus".