Alex Hyde / Orange tip butterfly egg (Anthocharis cardamines) on Cuckoo flower / Lady's smock (Cardamine pratensis). Peak DIstrict National Park, Derbyshire, UK. May.

Sandra Bartocha / Cowslip (Primula veris) and Cuckoo Flower (Cardamine pratensis) in flower with light effects, Brandenburger Vorstadt, Potsdam, Germany, April

Guy Edwardes / 2020VISION / Cuckoo flower / Lady's Smock (Cardamine pratensis), Catcott Lows SWT reserve, Somerset Levels, England, UK, April

Bernard Castelein / Orange Tip Butterfly (Anthocharis cardamines) at rest on Cuckoo-flower (Cardamine pratensis) Wuustwezel, Belgium, April

Bernard Castelein / Orange Tip (Anthocharis cardamines) at rest on Cuckoo-flower (Cardamine pratensis) Wuustwezel, Belgium, April

Bernard Castelein / Cuckoo-flower (Cardamine pratensis) Brasschaat, Belgium, April

Andy Sands / Orange Tip (Anthocaris cardamines) Male at rest on Cuckoo flower / Lady's smock, West Sussex, UK April

Bjorn Forsberg / Cuckoo flower {Cardamine pratensis} Sweden

Peter Lewis / Common Cuckoo (Cuculus canorus) perched on flowering Gorse (Ulex europaeus) Surrey, England, UK. April.

Peter Lewis / Cuckoo (Cuculus canorus) perched on Hawthorn blossom, Surrey, England, May.

Peter Lewis / Common Cuckoo (Cuculus canorus) perched on Cherry tree blossom Surrey, England, UK. April.

Peter Lewis / Common Cuckoo (Cuculus canorus) perched on branch of Hawthrorn (Cratageus monogyna) Surrey, England, UK.