are not known to interbreed with other owl species in the wild, and accordingly, no hybrids of snowy owls and other owl species have yet been sighted in the wild. However, a hobby falconer in Kollnburg, Germany, bred hybrids from a male snowy owl and a female Eurasian eagle-owl (Bubo bubo) in 2013. The two resulting male hybrid owls possessed the prominent ear-tufts (generally absent in snowy owls), general size, orange eyes, and the same pattern of black markings on their plumage from their Eurasian eagle-owl mother, while retaining the generally black-and-white plumage colours from their snowy owl father. The hybrids were dubbed "Schnuhus" from the German words for snowy owl and Eurasian eagle-owl (Schnee-Eule and Uhu, respectively). As of 2014, the hybrids had grown to maturity and were healthy. Description The snowy owl is mostly white. They are purer white than predatory mammals like polar bears (Ursus maritimus) and Arctic fox (Vulpes lagopus). Often when seen in the field, these owls can resemble a pale rock or a lump of snow on the ground. It usually appears to lack ear tufts but very short (and probably vestigial) tufts can be erected in some situations, perhaps most frequently by the female when she is sitting on the nest. The ear tufts measure about and consist of about 10 small feathers. The snowy owl has bright yellow eyes. The head is relatively small and, even for the relatively simply adapted hearing mechanism of a Bubo owl, the facial disc is shallow and the ear is uncomplicated. 1 male had ear slits of merely on left and on the right. Females are almost invariably more duskily patterned than like-age males. In mature males, the upper parts are plain white with usually a few dark spots on the miniature ear-tufts, about the head and the tips of some primaries and secondaries whilst the underside is often pure white. Despite their reputation for being purely white, only 3 out of 129 Russian museum specimens of adult males showed an almost complete absence of darker spots. The adult female is usually considerably more spotted and often slightly barred with dark brown on the crown and the underparts. Her flight and tail feathers are faintly barred brown while the underparts are white in base color with brown spotting and barring on the flanks and upper breast. In confusingly plumaged snowy owls, the sex can be determined