John Chan / Male California Least Tern (Sternula antillarum browni) courting a female, presenting a fish before chasing off another male, Huntington Beach, California, USA, May.

Frederique Olivier / Pair of Blue footed boobies (Sula nebouxii) courting, with the male picking up and offering grass, Isla Lobos de Terra, Peru.

Pal Hermansen / Artwork 'Give colours to the food-desert' by by Benedicte Lyssand. Purple tansy (Phacelia tanacetifolia) planted in corrected perspective of stripes 2m in foreground 7m in distance. Valer, Ostfold Cou...

Danny Green / Atlantic Puffin (Fratercula arctica) coming out of its burrow with a gift, Skomer Island, Wales, UK, May

Krijn Trimbos / Great crested grebe (Podiceps cristatus) pair in 'weed dance' courtship display, The Netherlands, March.

David Pattyn / Great crested grebe (Podiceps cristatus) pair performing their 'weed dance' in which they take a vertical position in front of each other and offer plant material to each other. The Netherlands. March...

Staffan Widstrand,Staffan Widstrand / Mangrove planting team from CRINEO planting Rhzophora mangrove trees, Pulicat Lake, Tamil Nadu, India, February 2013.

Mark Hamblin / 2020VISION / Portrait of a Roe deer (Capreolus capreolus) doe in rough grassland in summer, Scotland, UK, June 2011. Did you know? Female roe deer are called does and give birth in May and June, usually to twins.

Danny Green / 2020VISION / Viviparous / Common lizard (Zootoca /Lacerta vivipara) portrait, Staffordshire, England, UK, April. 2020VISION Book Plate. Did you know? Common lizards are both able to lay eggs and give birth.

Anup Shah / Common zebra about to give birth, Masai Mara, Kenya

Tony Phelps / Adder {Vipera berus} melanic / black form female with normal morph young. Dorset, UK