Wednesday, September 8, 2010

the birds of heaven have arrived

Today I saw and heard sandhill cranes for the first time this season. They arrive in their wintering grounds in the lower Cosumnes and North Delta beginning about now each year. These early arrivers are likely of the "greater" subspecies which nests in northeastern California and eastern Oregon. Arriving later, and in larger number, will be the "lessers," which nest in Alaska, northwestern Canada, and northeastern Siberia. All of these cranes of the Pacific Flyway spend their winters in California's Great Central Valley.

The cranes are large, ancient, and mystical. With a wingspan of 7 feet, a standing height of 4 feet, and a bright red head, the birds are visually striking. They are also among the oldest of birds, with a fossil dated at 2.5 million years and a close relative or ancestor dated at 10 million years. As a species, they've witnessed the movement and fusion of continents, repeated glacial cycles, oscillations of sea level of 100 meters or more, and the emergence and eventual global dominance of homo sapiens. That history offers some hope that they will successfully navigate the enormous changes underway in the Arctic as a result of climate change and the even greater changes looming for the Arctic and for California's Central Valley - but it's a slender thread of hope, because the current pace of climate change is without precedent in the geological record.

Because of their size, beauty, and ancient roots, as well as their haunting call, cranes have a central place in many of the world's mythologies and religions; they are often portrayed as intermediaries between heaven and earth. Cranes are revered as symbols of long life, happiness, marital fidelity, and love. Studies have determined that 80% of crane couples are monogamous for life - a significantly better achievement than that of contemporary homo sapiens in some cultures.

Globally, there are 15 species of cranes, occurring on all continents excent Antarctica and South America. Several species are highly endangered and on the brink of extinction. Different species of crane are national birds in China, South Africa, and Uganda.

The best months for viewing cranes in the North Delta and lower Cosumnes area are November and December. I happily share ideas for crane viewing.

No photo for this post, because no one has done it better than Michael Forsberg - Go there.

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