ABSTRACT
Strigidae, or typical owls, are familiar predatory birds that occur on every continent except Antarctica. Typical owls are socially monogamous and are generally characterized by fluffy, cryptic plumage and strong, zygodactylous feet. Typical owls in North America and Europe have a partial first cycle preformative molt (FPF) and a variable definitive prebasic molt (DPB); most large owls undergo an incomplete DPB, whereas smaller owls typically exhibit a complete DPB. These same patterns have been found in the Amazonian Pygmy-Owl at the study site and Great Horned Owl throughout South America, and probably occur in other Neotropical species. A word of caution: molt limits can be quite cryptic as complicated plumage patterns can create a seemingly endless combination of pseudolimits. Some researchers have successfully used ultraviolet (UV) light to show differences in feather generations when UV light is applied to the ventral surfaces of primaries and secondaries, where newer generations of feathers reflect greater intensities of fluorescence compared to older generations.
