The point might be an intuitive one to the experienced bird watcher, but it appears that morphological differences in an owl’s eye color might be an adaptation to foraging. Barn and barred owls have what seem to be opaque black marbles in their orbits and these, like other dark-eyed owls, prefer a nocturnal hunt. Possibly an adaptation for “invisibility” during moonlit evenings, the dark eyes reflect painfully little ambient light. The African eagle owl with its orange irises are crepuscular birds and thus prefer to forage at the break of dawn and dusk. While not true for all yellow-eyed owls, yellow irises are common to the agile daylight hunters. While it might be rare to see an owl hunt in midday, snowy owls, great grays and hawk owls will actively hunt even after the sun rises.

Many novice bird enthusiasts confuse large herons (Family Ardeidae) with cranes (Family Gruidae). Much like herons, cranes belong to a clade of long-legged and long-necked birds whose range often overlap. In contrast to the 64 extant heron species, there are only 15 distinct types of crane, two of which can be found in North America*. Unlike the herons, most crane species are threatened due to habitat loss throughout their migratory range. The large body, sculpted physique and intricate mating behavior has inspired art and poetry wherever cranes are found. Flying with outstretched neck and legs, most crane species migrate in large migratory flocks that congregate in evening and winter roosting sites. When attempting to distinguish a crane from a heron, look at the neck, legs and behavior and you will never get this wrong again.

(*Sandhill cranes (Grus canadensis) and whooping cranes (Grus americana) can be found in North America. The sandhill crane population is relatively stable across its range, while the whooping crane population is near extinct with a total of 599 captive and wild individuals. Population based on data from the International Crane Foundation - https://www.savingcranes.org/whooping-crane.html)

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