Andres M. Dominguez / Cork trees (Quercus suber) stripped of bark, in forest. Los Alcornocales Natural Park, Cortes de la Frontera, southern Spain, November.

Andres M. Dominguez / Ferns on the forest floor with Cork trees (Quercus suber )stripped of bark in the background, Los Alcornocales Natural Park, southern Spain, November

Andres M. Dominguez / Holm oak (Quercus ilex) in the Sierra de Grazalema Natural Park, Benaocaz, southern Spain, November.

Marie Read / Blue jay (Cyanocitta cristata) holding an acorn in its bill whilst perched on tree stump, with autumn foliage, New York, USA, October.

Dave Bevan / Slow motion clip of two pairs of Jackdaws (Corvus monedula) squabbling over nest site, Worcestershire, England, UK, May.

Bernard Castelein / Oak (Quercus robur) in Heather (Calluna vulgaris) at sunrise, Klein Schietveld, Brasschaat, Belgium

Ross Hoddinott / Ancient oak tree (Quercus robur), Marsland Mouth, Devon Wildlife Trust, Devon, UK. April 2017.

Andres M. Dominguez / Portuguese oak tree (Quercus faginea) covered in moss, Los Alcornocales Natural Park, southern Spain, November.

Andres M. Dominguez / Holm oak tree (Quercus ilex) in snowfall, Sierra de Grazalema Natural Park, southern Spain, January.

Solvin Zankl / Great capricorn beetle (Cerambyx cerdo) on Oak tree (Quercus sp) Niedersachsische Elbtalaue Biosphere Reserve, Lower Saxonian Elbe Valley, Germany, July.

Solvin Zankl / English oak tree (Quercus robur) in moonlight, Nauroth, Germany, February.

Niall Benvie / The Birnam Oak, an ancient English oak tree (Quercus robur) nearly 1000 years old, Perthshire, Scotland, UK, July.

Solvin Zankl / Gall wasp (Cynips quercusfolii) emerging from the oak gall. Germany, October.

Solvin Zankl / English oak tree (Quercus robur) silhouetted against orange sky with star trails, Nauroth, Germany, October.

Solvin Zankl / Springtail (Dicyrtomina ornata) on oak tree leaf. Niedersechsische Elbtalaue Biosphere Reserve, Elbe Valley, Lower Saxony, Germany, December.

Solvin Zankl / 'Femeiche' the Court Tree at night, an ancient English oak (Quercus robur) used in the Middle ages as Vehmic or secret court in which serious criminals were judged and executed. Erle, Germany, Octobe...

Solvin Zankl / Stag beetle (Lucanus cervus) silhouetted against oak tree leaf. Elbe, Germany, June.

Solvin Zankl / Stag beetle (Lucanus cervus) male on oak tree. Elbe, Germany, June.

Solvin Zankl / The Scarce Merveille du Jour (Moma alpium) caterpillar with urticating hairs on English oak tree (Quercus robur) leaf, Stettin Lagoon, Bay of Szczecin, Germany, August.

Kirkendall-Spring / Oak trees (Quercus) in the fog, Figueroa Mountain, Los Padres National Forest, California, USA.

Matthew Maran / Oak tree (Quercus robur) in snow, Hampstead Heath, London, UK, January 2013.

Ben Hall / Stunted oak woodland covered in moss, Wistman's Wood, Devon, UK. August. Highly Commended in the Wild Woods category of the British Wildlife Photography Awards (BWPA) competition 2013.

Jouan Rius / Black oak (Quercus velutina) in autumn, in Yosemite valley, Yosemite National Park, California, USA, December 2012.

Juan Carlos Munoz / Iberian black pig in oak woodland, Sierra de Aracena Natural Park, Huelva, Andalucia, Spain, Europe. Breed used to produce Iberico ham / Jamon Iberico

Juan Carlos Munoz / Iberian black pig foraging in oak woodland, Sierra de Aracena Natural Park, Huelva, Andalucia, Spain, Europe. Breed used to produce Iberico ham / Jamon Iberico

Theo Bosboom / Oak tree (Quercus sp) with snow in autumn, Rozendaalse Bos, near Arnhem, the Netherlands, November

Niall Benvie,Niall Benvie / Oak Eggar Moth (Lasiocampa quercus) against white background. France, July.

Sven Zacek,Sven Zacek / Famous Puhajarve war oak (Quercus) seen through dense fog. Southern Estonia, April 2011.

David Woodfall / Sessile oak (Quercus petraea) tree with sunlight behind, ancient semi natural woodland in Gilfach Nature Reserve, Radnorshire Wildlife Trust, Powys, Wales, UK May

Sandra Bartocha / English oaks (Quercus robur) trees with snow on trunks, Gespensterwald / Ghost wood, Nienhagen, Germany, January

Guy Edwardes / 2020VISION / View over New Forest heathland with Oak (Quercus robur) tree. Fritham Cross, New Forest National Park, Hampshire, England, UK, August. Did you know? The New Forest has the most extensive area of heath...

Rolf Nussbaumer / Northern raccoon (Procyon lotor) young at night climbing live Oak tree (Quercus virginiana) Dinero, Lake Corpus Christi, South Texas, USA.

Colin Varndell / English oak tree (Quercus robur) fallen acorns and leaves on a bed of moss, Oxfordshire, UK October.

Ross Hoddinott / 2020VISION / Close up of acorns and autumnal foliage ofEnglish oak (Quercus robur), Arne RSPB reserve, Dorset, England, UK, September. Did you know? Acorns are not produced until the tree is at least 40 years old.

Alex Hyde / Purple emperor butterfly (Apatura iris) male on English Oak (Quercus robur) leaf basking with wings open, UK, Captive.

Fabrice Cahez / Oak (Quercus sp) forest at dawn, Vosges, France, January

Pascal Tordeux / Oak (Quercus) covered with frost. Picardy, France.

Peter Cairns / 2020VISION / Sessile Oak tree (Quercus petraea) in spring, Sunart Oakwoods, Ardnamurchan, Highland, Scotland, UK, May. 2020VISION Book Plate.

Niall Benvie / 2020VISION / Atlantic oak wood (Quercus petraea), Achduart, Coigach and Assynt, Sutherland, Scotland, UK, June 2011. Did you know? 284 species of insect are reliant on oak trees.

David Woodfall / Sessile Oak (Quercus patraea) in mist. Gilfach Farm SSSI, Radnorshire Wildlife Trust, Wales, UK, November.

Rolf Nussbaumer / Virginia creeper (Parthenocissus quinquefolia), climbing on Live Oak (Quercus virginiana) with fall colors, Kerrville, Hill Country, Central Texas, USA, November.

Ross Hoddinott / 2020VISION / English oak tree {Quercus robur} acorn sprouting a fresh shoot, Beacon Hill Country Park, The National Forest, Leicestershire, UK, November. Did you know? In Norse legend the Oak tree was sacred to T...

Ross Hoddinott / 2020VISION / English oak tree {Quercus robur} acorn and fallen leaves in autumn, Beacon Hill Country Park, The National Forest, Leicestershire, UK, November

Ross Hoddinott / 2020VISION / New planting of young sapling English Oak tree (Quercus robur) in protective plastic ‘collar’, Feanedock Wood, The National Forest, Derbyshire, UK, November 2010.

Ross Hoddinott / 2020VISION / English oak {Quercus robur} leaf in autumn, Donisthorpe, The National Forest, Leicestershire, UK. November. Did you know? There are more than 600 species of oak around the world.

Mark Taylor / English Oak (Quercus robur) standing solitary in a field. Surrey, UK, October. Year sequence, 3 of 4 (autumn).

Mark Taylor / English Oak (Quercus robur) standing solitary in a field. Surrey, UK, November. Year sequence, 1 of 4 (winter).

Ernie Janes / Seedling English oak tree (Quercus robur) in the rain, UK