Niall Benvie / Queen Mary's Tree, a veteran Sweet chestnut (Castanea sativa) over 600 years old, Cumbernauld, Scotland, UK, July.

Juan Carlos Munoz / Chestnuts from Sweet chestnut tree {Castenea sativa} Redes NP, Asturias, Northern Spain, October 2007

David Tipling / Grey squirrel (Sciurus carolinensis) collecting sweet chestnuts (Castanea sativa) to cache for winter. Richmond Park, London, England, UK. October.

David Tipling / Grey squirrel (Sciurus carolinensis) collecting sweet chestnuts (Castanea sativa) to cache for winter, Richmond Park, London, England, UK. October.

David Tipling / Grey squirrel (Sciurus carolinensis) collecting sweet chestnuts (Castanea sativa) to cache for winter, Richmond Park, London, England, UK. October.

Doug Wechsler / Eastern chipmunk (Tamias striatus) gathering chestnuts, Chestnut Hill, Philadelphia, Pennsylvania, USA, September.

Ernie Janes / Sweet chestnut (Castanea sativa) leaves and fruits in autumn, Norfolk, England, UK, August.

Dave Bevan / Eurasian jay (Garrulus glandarius) foraging for sweet chestnuts amongst leaf litter, Carmarthenshire, Wales, UK, November.

Cyril Ruoso / Chesnuts (Castanea vesca) fallen from tree on forest floor, Alberes Mountains, Pyrenees, France, September.

Georgette Douwma / Horse chestnuts (Aesculus hippocastanum) conkers, UK.

Georgette Douwma / Horse chestnuts (Aesculus hippocastanum) conkers, UK.

Colin Varndell / Sweet chestnuts (Castanea sativa) on forest floor. New Forest, Hamphire, UK, September.

Alex Hyde / Chestnuts on Sweet Chestnut tree (Castanea sativa), Nottinghamshire, UK. October.

Yukihiro Fukuda / Japanese squirrel (Sciurus lis) foraging among fallen chestnuts, Mount Yatsugatake, Nagano Prefecture, Japan. Endemic species.

Yukihiro Fukuda / Collection of food eaten Japanese squirrel (Sciurus lis) including chestnuts, Walnut (Juglans ailantifolia), pine cones, Mount Yatsugatake, Nagano Prefecture, Japan, October. Endemic species.

Wild Wonders of Europe / Lundgren / Danube Delta fisherman Florin Moisa navigating through the Water chestnuts (Trapa natans) Danube Delta, Romania, June 2013.

Adrian Davies / Chestnuts from a Sweet chestnut tree (Castanea sativa) on forest floor, Surrey, England, UK, October

Adrian Davies / Chestnuts from a Sweet chestnut tree (Castanea sativa) on forest floor, Surrey, England, UK, October

Philippe Clement / Spiny husk splitting open and showing chestnuts of the Sweet chestnut tree / marron (Castanea sativa) on the forest floor, Belgium, October

Philippe Clement / Spiny cupules and chestnuts of the sweet chestnut tree / marron (Castanea sativa) amongst autumn leaves on the forest floor, Belgium, October

Philippe Clement / Spiny cupules and chestnuts of the sweet chestnut tree / marron (Castanea sativa) amongst autumn leaves on the forest floor, Belgium, October

Adrian Davies / Sweet chestnut (Castanea sativa) spiny cupules containing chestnuts in autumn, Sussex, England, UK, October

Adrian Davies / 'Do Not Take Chestnuts' sign, Richmond Park, Surrey, England, UK, October 2011

Ernie Janes / Sweet chestnuts (Castanea sativa) for sale in market stall, Madeira, November

Ernie Janes / Sweet chestnuts (Castanea sativa) on woodland floor, Europe, November

Juan Carlos Munoz / Chestnuts from Sweet chestnut tree {Castenea sativa} Redes NP, Asturias, Northern Spain, October 2007

Juan Carlos Munoz / Chestnuts from Sweet chestnut tree {Castenea sativa} Redes NP, Asturias, Northern Spain, October 2007

Juan Carlos Munoz / Chestnuts from Sweet chestnut tree {Castenea sativa} Redes NP, Asturias, Northern Spain, October 2007

Juan Carlos Munoz / Chestnuts from Sweet chestnut tree {Castenea sativa} Redes NP, Asturias, Northern Spain, October 2007

Philippe Clement / Sweet chestnuts (Castanea sativa), Europe

Philippe Clement / Sweet chestnuts (Castanea sativa), Europa

David Kjaer / Red Deer (Cervus elaphus) Stag feeding on Horse Chestnuts, Richmond Park, London, UK

Philippe Clement / Sweet Chestnuts {Castanea sativa} leaves and spiny cupules containing nuts, Belgium

Juan Manuel Borrero / Sweet chestnuts {Castanea sativa} Las Medulas NP, Leon, Spain

Philippe Clement / Sweet chestnuts {Castanea sativa} Belgium

Philippe Clement / Sweet chestnuts {Castanea sativa} Belgium

Fabio Liverani / Autumn trees in the Foreste Casentinesi, Monte Falterona, Campigna: a millenary forest in the Apennines of Tuscany and Romagna, Italy

David Tipling / Ring-necked / Rose-ringed parakeet (Psittacula krameri) feeding on Sweet chestnuts (Castanea sativa), Bushy Park, London, UK. September.

Paul Harcourt Davies / Sweet chestnut (Castanea sativa) burr split to reveal the chestnuts within, Umbria, Italy. November.

Brian Bevan / Melanistic Grey squirrel (Sciurus carolinensis) sitting in tree feeding on chestnut, Bedfordshire, UK,

Colin Varndell / Horse chestnuts (Aesculus hippocastanum) in leaf litter. Dorset UK September.

Ernie Janes / Bramble leaves, bryony, rosehips, chestnuts and bracken fronds changing colour in autumn, against a white background.

Will Watson / Avenue of flowering veteran Sweet chestnuts (Castanea sativa), Herefordshire Parkland, England, July.

Philippe Clement / Country lane lined with 200 year old sweet chestnut trees (Castanea sativa) covered in snow during snowfall in winter, Belgium, January