They're back. It was three years ago when I first observed cliff swallows swooping and nesting along the canal that divides my Phoenix neighborhood into two halves. And it was ever since that I wondered whether they'd ever return. But they didn't, at least not to their expected nesting spots, until now.
While many migratory birds spend the winter in the cool and mild weather of Arizona's deserts, those same birds travel north for their summer breeding season. It's quite normal to see white-crowned sparrows and green-winged teals in the area in January but by the summer they escape the sweltering heat to breed as far north as Canada.
But cliff swallows are not limited to just the North America continent in their own migrations. They spend our winters in South America, as far south as Argentina, and travel to our northern hemisphere, including Arizona, for a summer breeding season. While their nesting habitat used to be limited to western river canyons, and yes, cliffs, the widespread construction of concrete bridges and overpasses across the continent has created an unlimited supply of manmade structures to shelter under.
They seem to arrive in our urban canyons every spring as I first photographed them four years ago high in their nests under the towering freeways that follow the Salt River. Thanks to the development of a recreational lake, there is plenty of water and mud for the birds to build their concrete-hugging abodes.
Closer to my home, they build these nests under much lower bridges: ones that cross the Arizona Canal, a channel that brings river and reservoir water to parched communities across the Valley. These mud pueblos lie abandoned most years, at least among cliff swallows. Instead, house sparrows often take over year-round residence.
But this year, on the closest canal bridge to my home, I've been thrilled to see cliff sparrows reclaiming and enhancing nests I've never seen them occupy before. Apparently this irregular occupancy serves a biological purpose, giving the dwellings time to passively rid themselves of parasites.
Flying extraordinary distances, thriving in extremely hot temperatures, engineering safe abodes: the cliff swallow possesses amazing avian skills. But they're also singularly beautiful creatures, sporting a red, white and blue palette that is well worth a step outside on a hot day to admire under your nearest bridge.
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While many migratory birds spend the winter in the cool and mild weather of Arizona's deserts, those same birds travel north for their summer breeding season. It's quite normal to see white-crowned sparrows and green-winged teals in the area in January but by the summer they escape the sweltering heat to breed as far north as Canada.
But cliff swallows are not limited to just the North America continent in their own migrations. They spend our winters in South America, as far south as Argentina, and travel to our northern hemisphere, including Arizona, for a summer breeding season. While their nesting habitat used to be limited to western river canyons, and yes, cliffs, the widespread construction of concrete bridges and overpasses across the continent has created an unlimited supply of manmade structures to shelter under.
They seem to arrive in our urban canyons every spring as I first photographed them four years ago high in their nests under the towering freeways that follow the Salt River. Thanks to the development of a recreational lake, there is plenty of water and mud for the birds to build their concrete-hugging abodes.
Closer to my home, they build these nests under much lower bridges: ones that cross the Arizona Canal, a channel that brings river and reservoir water to parched communities across the Valley. These mud pueblos lie abandoned most years, at least among cliff swallows. Instead, house sparrows often take over year-round residence.
But this year, on the closest canal bridge to my home, I've been thrilled to see cliff sparrows reclaiming and enhancing nests I've never seen them occupy before. Apparently this irregular occupancy serves a biological purpose, giving the dwellings time to passively rid themselves of parasites.
Flying extraordinary distances, thriving in extremely hot temperatures, engineering safe abodes: the cliff swallow possesses amazing avian skills. But they're also singularly beautiful creatures, sporting a red, white and blue palette that is well worth a step outside on a hot day to admire under your nearest bridge.
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| Nesting cliff swallows on the Arizona Canal near the Biltmore. |
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| Cliff swallow. |
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| Cliff swallow. |
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| Cliff swallow. |
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| Cliff swallows reclaiming and enhancing mud nests. |
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| House sparrow in a cliff swallow nest. |
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| Flying cliff swallow on the Arizona Canal. |
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| Flying cliff swallow approaching its protected nest under a bridge on the Arizona Canal in the Biltmore section of Phoenix. |
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