Harmonized alterations in flower and bill shape have aided the formation of new species of both hummingbirds and plants, Aaron Sm reports for The State Column.
Researchers have revealed the first complete map of hummingbirds’ 22-million-year old family tree. The map–developed based on a meticulous study of 284 of the world’s 338 known species–uncovers a tale of very quick and continuous diversification.
According to the researchers, the hummingbirds’ extraordinary prosperity is based, in part, on three factors: the development of nine clades, the birds’ unusual relationship with flowering plants and the birds’ persistent expansion into new geographic regions.
“Hummingbirds have essentially been reinventing themselves throughout their 22-million-year history,” explains Jim McGuire of the University of California, Berkeley.
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According to the Smithsonian, the bee hummingbird of Cuba is only 1.95 grams. The calliope hummingbird, the fourth tiniest bird, weighs in at 2.5 grams and can be observed in the mountains of western North America.
The birds’ family tree reveals that ancestral hummingbirds split from the swifts and treeswifts approximately 42 million years ago, likely in Eurasia. When the ancestral species of all modern hummingbirds arrived in South America approximately 22 million years ago, hummingbird evolution went into overdrive. Today, about 140 hummingbird species reside in the Andes Mountains.
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“Our findings strongly indicate that hummingbirds remain engaged in a dynamic diversification process, filling available ecological and spatial niches across North America, South America, and the Caribbean,” the researchers contend.
The study’s findings are published in the journal Current Biology.