Saturday, August 18, 2012

Pic of the Day

Gila Woodpecker at nest;
Catalina State Park, Arizona
     Gila Woodpecker; Melanerpes uropygialis and Brown-crested Flycatcher; Myiarchus tyrannulus– Catalina State Park; Tucson, Arizona:  
     When I arrived at Catalina State Park this summer the first thing I saw was the open fruit on the gigantic saguaro cactus at the parks entrance.  A number of the cacti were covered with open fruit and a plethora of birds were visiting the cacti to feed on the fruit.  I had arrived at just the right time of the year, many of the species that nest in southeast Arizona were breeding and feeding their nestling saguaro fruit. 
     This Gila Woodpecker was found forty feet from the park entrance nesting in a saguaro cactus. Saguaros live from 150 to 200 years and can reach heights of 70 feet.  Judging from the size of the arms that was on this particular saguaro its age must excide 150 to 175 years.

Saguaro Cacti, Organ Pipe National Monument
     Saguaros are the trees of the forest and home to many desert species from mammals and reptiles to birds.  Woodpeckers like this Gila, drills holes into the cactus just like it would a tree.  In fact, the internal structure of the saguaro is an intricate intertwined woody ribbed structure, necessary to support a cactus that weighs 10 to 15 tons.  Yes, 10 to 15 tons……seems unbelievable.
     Once the cavity is excavated the cactus begins to secrete a mucus (for a better word) that coats the damage.  The coating stops the loss of precious water stored in the cactus.  The harden cavity becomes a perfect home for the birds and other wildlife that inherit the cavity over time.  Even after a saguaro dies and falls to the ground, the cavity, called a boot serves as a dwelling for ground creatures.

     Other birds that use the excavated cavities of the woodpeckers are Elf Owls, Ash-throated and pictured here, the Brown-crested Flycatchers.  In spring and summer and fall the saguaro provides much need insulation from the head and in winter, insulation from the cold. 
     Saguaro Cactus are found only in Arizona, with a few spilling over into extreme southeastern California and in western Sonara, Mexico.  I will post more birds photographed in Catalina State Park and the desert southwest in future updates.

Gila Woodpecker:  Nikon D7000, Nikkor 500mm f4, 1/500 second @ f8, Tripod

Saguaro Cacti: Nikon F4, Kodachorme 64, exposure unknown, Tripod
Brown-crested Flycatcher: Nikon D7000, Nikkor 500mm f4, 1/160 second @ f7.1, Tripod
Brown-crested Flycatcher at nest:
Catalina State Park, Arizona

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