
Karl Martens, WHITE-TAILED EAGLE

Karl Martens, CRANE

Karl Martens, HEN HARRIER III

Karl Martens, GOLDEN EAGLE

Karl Martens, GADWALL

Karl Martens, WHITE TAILED SEA EAGLE

Karl Martens, HEN HARRIER I

Karl Martens, RED KITE I

Karl Martens, LAPWINGS

Karl Martens, DOVE I

Karl Martens, SHORT EARED OWL

Karl Martens, GOSHAWK

Karl Martens, BLACKBIRD

Karl Martens, GREENFINCH

Karl Martens, SHORT EARED OWL I

Karl Martens, FIELD MOUSE

Karl Martens, CRANE (2)

Karl Martens, CURLEW

Karl Martens, GYR FALCON

Karl Martens, FIELD HARE

Karl Martens, CRANE IN REEDS

Karl Martens, GREAT GREY OWL

Karl Martens, RAVEN

Karl Martens, GREY HERON

Karl Martens, SHREW

Karl Martens, KESTREL

Karl Martens, WHITE-TAILED EAGLE LITHOGRAPH

Karl Martens, GOLDEN ORIOLE

Karl Martens, HOOPOE

Karl Martens, GOLDEN EAGLE (2)

Karl Martens, HAWK OWL

Karl Martens, SNOWY OWL

Karl Martens, KINGFISHER

Karl Martens, DORMOUSE

Karl Martens, SPARROWHAWK

Karl Martens, BOREAL OWL

Karl Martens, BLACKBIRD, FEMALE

Karl Martens, BITTERN