There’s an odd feeling waking up from a dream and not being able to recall any of its details. A color, a feeling, a flavor might stand out, but the context is elusive. Trying to define “natural history” gives me the same feeling. Rarely used in everyday life, I don’t have a good sense of context to give it meaning.
The term may be vague, in part, because it is a moving target. I understand natural history to refer to a species’ habits or a habitat’s history: everything that is known about that species or place. But life – from the species level to an entire ecosystem scale – is always changing and histories are constantly being rewritten. One recent example came out of Florida where American Kestrels were observed using an unusual nest site.
The natural history of kestrels tells us that they nest in ready-made cavities: natural tree hollows, old woodpecker holes, or rock crevices. They have also expanded in recent years into man-made nest boxes. But now kestrels have been observed using a nest built by a non-native species.
Monk Parakeets, native to South America, were brought to the United States in large numbers through the exotic pet trade. Some escaped and quickly established colonies in southern Florida. Unlike other parrots, these parakeets build large stick nests with separate chambers for 20 pairs or more. The nests are typically found in trees, but silos and utility poles are also used.
The nest cavities must be just the right size for kestrels, too. Two pairs of American Kestrels were observed re-purposing parakeet nests for their own families, and both successfully fledged young at the end of the season. As a species in decline, it is exciting to see kestrels taking advantages of new opportunities and re-writing their natural history.