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

Juan Carlos Munoz / Ferns growing near fallen tree in Chestnut forest, Onati, Gipuzkoa, Basque Country, Spain, Europe

Gary K. Smith / Woodland floor with purple fungi Amethyst Deceiver (Laccaria amethystina), and fallen seed cases and fruit of Sweet Chestnut tree (Castanea savita) Norfolk, UK, October

Terry Whittaker / 2020VISION / Hazel dormouse (Muscardinus avellanarius) running up branch in coppiced hazel tree, Kent, UK. Photographed in wild under licence with remote camera (camera trap), October

Terry Whittaker / 2020VISION / Hazel dormouse (Muscardinus avellanarius) in coppiced hazel tree, Kent, UK. Photographed in wild under licence with remote camera (camera trap), September. 2020VISION Book Plate.

Angelo Gandolfi / Ancient Sweet Chestnut trees (Castanea sativa) growing in the Spelunca Gorges. Porto, Parc Naturel Regional de Corse, Corsica island, France, January 2010

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

Andrew Parkinson / Grey squirrel {Sciurus carolinensis} adult standing alert among the fallen leaves of Horse Chestnut tree, Derbyshire, UK

Jose B. Ruiz / Sweet chestnut saplings, San Martin de Trevejo, Las Hurdes, caceres, Extremadura, Spain

Geoff Simpson / Horse chestnut tree sticky bud opening {Aesculus hippocastanum} England

Nigel Cattlin / Horse chestnut leaf miner (Cameraria ohridella) larval damage to Horse chestnut (Aesculus hippocastanum) leaves. Berkshire, England, UK. August.

David Tipling / Chestnut-bellied monarch (Monarcha castaneiventris) perched in tree. Nara, Makira, Solomon Islands.

Ernie Janes / Horse chestnut (Castanea sativa) new leaves.

Heather Angel / Bumblebee (Bombus sp) nectaring on Indian horse chestnut flower (Aesculus indica). Yellow spots on banner petals turn pink as nectar resource declines. Orange pollen is pick ed up on wings and thorax...

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

Ernie Janes / Sweet chestnut (Castanea sativa) trunk and bark patterns of ancient tree, Norfolk, England, UK, November.

Markus Varesvuo / Chestnut-winged cuckoo (Clamator coromandus) perched in tree. Happy Island, Hebei Province, China. May.

David Tipling / Western jackdaw (Corvus monedula) flying with Sweet chestnut (Castanea sativa) in beak. 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.

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

Nick Upton / Horse Chestnut (Aesculus hippocastanum) flower candelabras Wiltshire, UK, May.

Colin Varndell / Sweet chestnut (Castanea sativa) seeds and seed case on ground, Dorset, England, UK.

Adrian Davies / Horse chestnut (Aesculus hippocastanum) flowers. Surrey, England, UK. May.

Matthew Maran / Veteran sweet chestnut (Castanea sativa) approaching 200 years of age. Devon, England, UK, November.

Matthew Maran / Veteran sweet chestnut (Castanea sativa) approaching 200 years of age. Devon, England, UK, November.

Nick Upton / Horse chestnut (Aesculus hippocastanum) sticky buds, Wiltshire, UK, September. The buds of horse chestnut are covered in a sticky gum like substance, which protects the from insects.

Nick Upton / Horse chestnut (Aesculus hippocastanum) sticky buds, Wiltshire, UK, September. The buds of horse chestnut are covered in a sticky gum like substance, which protects the from insects.

Ernie Janes / Horse chestnut (Castanea sativa) tree conkers / seeds, Norfolk, England, UK, September.

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

Robert Thompson / Horse chestnut (Aesculus hippocastanum) Clare Glen, County Armagh, Northern Ireland. October.

Ernie Janes / Five-lobed sterculia (Sterculia quinqueloba) tree growing on rocky hillside, Namibia

Gary K. Smith / Sweet chestnut (Castanea sativa) close up of tree trunk and bark. England, UK. September

Will Watson / Shaggy inkcap (Coprinus comatus) growing beneath Horse chestnut (Aesculus hippocastanum) tree, Herefordshire Plateau, England, UK, October .

Angelo Gandolfi / Giant ancient Chestnut tree (Castanea Sativa) with woman, Sila Greca, Sila National Park, Parco Nazionale della Sila UNESCO World Heritage Site, Calabria, Italy, June.

Angelo Gandolfi / Ancient Chestnut tree (Castanea Sativa). Sila Greca, Sila National Park, Calabria, Italy, June.

Angelo Gandolfi / Woman standing in hollow of ancient Chestnut tree (Castanea Sativa). Sila Greca, Sila National Park, Parco Nazionale della Sila UNESCO World Heritage Site, Calabria, Italy, June.

Angelo Gandolfi / Chestnut tree (Castanea Sativa) at night, Sila Greca, Sila National Park, Calabria, Italy, June.

Angelo Gandolfi / Giant Chestnut tree (Castanea Sativa). June, Sila Greca, Sila National Park, Calabria, Italy

Angelo Gandolfi / Giant Chestnut tree (Castanea Sativa) Sila Greca, Sila National Park, Calabria, Italy. June,

Angelo Gandolfi / Chestnut trees (Castanea sativa) in flower with poppies, Sila Greca. Sila National Park, Calabria, Italy. June.

Philippe Clement / Low angle shot of a Red oak tree (Quercus rubra) showing leaves in autumn colours, October, Belgium.

Philippe Clement / Sweet chestnut tree (Castanea sativa) in autumn, October, Belgium.

Kim Taylor / New trees growing from wind-blown Sweet chestnut (Castanea sativa) Surrey, England, November.

Kim Taylor / New trees growing from wind-blown Sweet chestnut (Castanea sativa) Surrey, England, November.

Russell Cooper / Horse Chestnut leaf (Aesculus hippocastanum) infected by Mining moth caterpillar (Cameraria nemoralis) Southwest London, England, UK, July.

Nick Hawkins / Black-mandibled toucan (Ramphastos ambiguus swainsonii) in the lowland rainforests, Southeastern Nicaragua. August.

Sylvain Cordier / Horse chestnut seedling (Aesculus hippocastanum), Alsace, France, May.

Fabrice Cahez / Sweet chestnut (Castanea sativa) Vosges, France, October.

Fabrice Cahez / European horse-chestnut (Aesculus hippocastanum) fruit and seeds, Vosges, France

Fabrice Cahez / European horse-chestnut (Aesculus hippocastanum) fruit, Vosges, France

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

Andres M. Dominguez / Alpine longhorn beetle (Rosalia alpina) a rare and protected longhorn beetle living on rotten chestnut tree trunks, Cantabria, Spain, August

Mike Read / Sweet chestnut (Castanea sativa) individual leaf on lightbox Ringwood Hampshire UK October

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

Colin Varndell / Detail of bark texture on mature Horse chestnut (Aesculus hippocastanum) tree in field near Upton Country Park, Dorset, UK, May.

Colin Varndell / Sweet chestnut tree (Castanea sativa) capsule and nut. Dorset, UK September.

Adrian Davies / Kelumpang Sarawak tree (Sterculia megistophylla) close up of seeds, botanic garden, Sabah, Borneo.

Juan Carlos Munoz / Moss covered fallen tree and ferns growing in Chestnut forest, Onati, Gipuzkoa, Basque Country, Spain, May.

Juan Carlos Munoz / Woman standing near large Sweet chestnut (Castanea sativa) tree, Chestnut forest, Onati, Gipuzkoa, Basque Country, Spain, May.

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

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

Simon Colmer / Conker or Horse chestnut (Aesculus hippocastanum) in case, on white background. September.

Simon Colmer / Conker or Horse chestnut (Aesculus hippocastanum) in case, on white background. September.

Russell Cooper / Horse chestnut tree seeds or conkers (Aesculus hippocastanum) South-west London, UK, September.

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

Nick Upton / Horse Chestnut (Aesculus hippocastanum) leaf buds opening, Wiltshire, UK, April.

Nick Upton / Horse Chestnut (Aesculus hippocastanum) flowers, Wiltshire, UK, May.

Alex Hyde / Horse Chestnut (Aesculus hippocastanum) bud. Peak District National Park, Derbyshire, UK. April.

Alex Hyde / Horse Chestnut (Aesculus hippocastanum) bud. Peak District National Park, Derbyshire, UK. April.

Alex Hyde / Horse Chestnut (Aesculus hippocastanum) bud. Peak District National Park, Derbyshire, UK. April.

Alex Hyde / Horse Chestnut leaves (Aesculus hippocastanum) infected with Leaf Miner Moth (Cameraria ohridella) on a white background. Peak District National Park, Derbyshire, UK. July. This insect is an invasive...

Alex Hyde / Horse Chestnut leaves (Aesculus hippocastanum) infected with Leaf Miner Moth (Cameraria ohridella) Peak District National Park, Derbyshire, UK. July. This is an invasive species.

Ben Cranke / Black-collared Hawk (Busarellus nigricollis) perched in a tree top, Mato Grosso, Pantanal, Brazil. August.

Ben Cranke / Black-collared Hawk (Busarellus nigricollis) perched in a tree top, Mato Grosso, Pantanal, Brazil. August.

Adrian Davies / Horse chestnut tree (Aesculus hippocastanum) flowers in spring. Surrey, England, April.

Philippe Clement / Horse-chestnut / conker tree (Aesculus hippocastanum) flowers and leaves in spring, UK, May.

Adrian Davies / Horse chestnut (Aesculus hippocastanum) flowering in spring. Surrey, England, April.

Adrian Davies / Horse chestnut (Aesculus hippocastanum) flowering in spring. Surrey, England, April.

Adrian Davies / Horse chestnut (Aesculus hippocastanum) flowering in spring. Surrey, England, April.

Adrian Davies / Horse chestnut (Aesculus hippocastanum) flowering in spring. Surrey, England, April.

Carol Walker / Chestnut Mustang running in snow, at ranch, Shell, Wyoming, USA. February.

Nick Upton / Ripening fruits of Horse chestnut tree (Aesculus hippocastanum), Wiltshire, UK, September.

Luiz Claudio Marigo / Chestnut-eared Aracari (Pteroglossus castanotis) in tree, Pantanal, Mato Grosso State, Western Brazil.

Luiz Claudio Marigo / Chestnut-eared Aracari (Pteroglossus castanotis) in tree, Pantanal, Mato Grosso State, Western Brazil.

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

Colin Varndell / Sweet chestnut (Castanea sativa) nuts held in hands, Dorset, UK October,

Alex Hyde / Horse Chestnut (Aesculus hippocastanum) leaves emerging from buds. Peak District National Park, Derbyshire, UK, May.

Alex Hyde / Horse Chestnut (Aesculus hippocastanum) leaves emerging from buds. Peak District National Park, Derbyshire, UK, May.

Nick Upton / Horse Chestnut tree (Aesculus hippocastanum) with major branch broken off during a storm, Wiltshire, UK, May.

Jack Dykinga / Chestnut mandibled toucan (Ramphastos ambiguus swainsonii) in tropical rainforest canopy with beech almond fruit. Osa Peninsula, Costa Rica

Juan Carlos Munoz / The Hundred Horse Chestnut, an ancient Sweet chestnut (Castanea sativa) believed to be up to 4000 years old, which also has the largest trunk in the world, Sant'Aflio, Sicily, Italy

Paul Harcourt Davies / Ancient chestnut tree trunk (Castanea sativa) on Mount Cimino, near Viterbo, Italy, April

Paul Harcourt Davies / Ancient chestnut tree trunk (Castanea sativa) covered in lichen, on Mount Cimino, near Viterbo, Italy, April

Denis-Huot / Malabar chestnut (Pachira aquatica) flower, Tortugueros National Park, Costa Rica

Will Watson / Horse Chestnut (Aesculus hippocastanum) leaves with Leaf minor (Cameraria ohridella) Herefordshire, UK November 2012