Marie Read / Common redpoll (Carduelis flammea), male perched in alder (Alnus rugosa) during a snowstorm in winter, New York, USA, January.

Sven Zacek / Ural owl (Strix uralensis) perched on Alder (Alnus sp) tree at dusk. Tartumaa, Southern Estonia. April.

Kim Taylor / Redpoll (Carduelis flammea) male landing on Alder (Alnus glutinosa) Surrey, England. February

Floris van Breugel / Emerging spring leaves adorn the mossy trees - Vine Maple (Acer circinatum) and Alder (Alnus rubra) in Mt Baker - Snoqualmie National Forest. Washington. April 2013

Mark Hamblin / 2020VISION / Alder trees (Alnus hirsuta) silhouetted and reflected in River Spey in winter, Cairngorms NP, Scotland, UK, December 2010

Florian Möllers / Alder trees (Alnus sp) reflected in standing water in nature reserve, Berlin, Germany, May 2009

Wild Wonders of Europe / della Ferrera / Pool of water left over from the flooded season in a Grey alder (Alnus incana) forest between Koutarica and Mlaka, Lonjsko Polje Nature Park, Sisack-Moslavina county, Slavonia region, Posavina area, C...

Wild Wonders of Europe / Möllers / Sun shining through trees in Common alder (Alnus glutinosa) forest, Klampenborg Dyrehaven, Denmark, September 2008

Yukihiro Fukuda / Japanese macaque / Snow monkey {Macaca fuscata} male grooming female in courtship in Japanese green alder tree {Alnus firma}, autumn, Jigokudani, Nagano, Japan

Simon Colmer / Common alder (Alnus glutinosa) bud in winter, UK

Ross Hoddinott / Common alder (Alnus glutinosa) catkins silhouetted. Cornwall. UK

Bernard Castelein / Alder buckthorn (Frangula alnus) tree at dawn. Klein Schietveld, Brasschaat, Belgium. April.