The Purple Martin is the largest swallow that nests in the US and Canada. During fall, Purple Martins from western North America migrate to a distinct wintering area in southeastern Brazil — a travel distance of more than 5,000 miles! Scientists believe that Purple Martins started out as a South American swallow species. Over time, they evolved a seasonal migration to North America because the longer days of summer sunlight provided extra hunting and feeding opportunities during nesting season.

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Imagine a pigeon the size of a Turkey Vulture or a Canada Goose! Meet the crowned-pigeon. Four species inhabit the large, equatorial island of New Guinea and a few smaller islands. Crowned-pigeons are forest birds and fruit-eaters, with iridescent purple chests and spectacular, tall, lacy crests.

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To figure out the source of a hummingbird’s hum, scientists built a special rig to measure air pressure, twelve high-speed cameras, and over 2,000 microphones to observe hummingbirds fluttering in place at an artificial flower. The researchers found that the hum derives from the difference in air pressure between the top and bottom of the wings, which alternates forty times a second as the hummingbird flaps. The rapidly shifting air pressure produces a harmonic set of sounds, from low to high, creating that iconic, musical hum.

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