Thursday, January 21, 2010

The Great Horned Owls of Casa Grande

We recently visited Casa Grande Ruins National Monument in Coolidge Arizona. Casa Grande ruins of multiple Hohokam buildings and walls. The Tohono O'odham, who are descended from the residents of Casa Grande, call the place "Siwan Wa'a Ki." The main building and namesake of Casa Grande was abandoned by the Hohokam nearly 700 years ago. It's made of caliche, which is made from calcium carbonate, and works like a type of cement. In 1932 the parks service constructed the massive roof to protect the abused and suffering building from the elements.
Casa Grande
Interestingly, though the building has been abandoned for generation, others now occupy the roof structure and call it home. Who are these new residents of Casa Grande?
Casa Grande Owls
Casa Grande is the home of a nesting pair of great horned owls! We noticed them before our tour guide even pointed them out. I guess I just have that extra sense for seeing owls.
Casa Grande Owls
I sent a quick email to the staff at Casa Grande and asked for some more history or information about the owls.  Ashley McCabe, who's a biological science technician, was kind enough to respond. Here's what she wrote about the owls:
"The two current Great Horned Owl occupants of the "Great House" at Casa Grande Ruins National Monument are a nesting pair. One of the pair was first recorded here in 2004 and the other has been here since 2006. The owl that has been here since 2004 had a previous mate that was hit by a car in October 2006. The second mate came in November 2006, apparently to take the place of the one that died. In January 2009, our resource management staff relocated a Great Horned Owl nestling from the west wall of the Great House to a nesting box on the southwest corning of the ruins shelter in order to avoid continuing damage to the prehistoric structure. The nestling successfully fledged from the nesting box. We expected the nestling to leave around August 2009, but the bird did not leave until December. Because of the curiosity the nestling displayed, it was the most interesting of the three owls to monument staff and visitors. The bird was often heard screeching during the day."
 If you ever visit Casa Grande, don't forget to look up! 


Andy said...

Interesting. I have a shot of Casa Grande in 1987 and it has no roof. Have I misattributed it? It's entirely possible. And if so, have you any idea where I took my picture?

Eric said...

Hey Andy. I'm not sure where that is. The roof was built in 1932 and it's huge, so if you don't remember seeing it, this probably isn't Casa Grande National Monument. However, my photo is of what they call the "Big House" and it's not the only structure there. Your photo may be of one of the smaller structures at CGNM. I wish I could be of more assistance, but, whatever it's a picture of, it's a cool picture!

Andy said...

Thanks for that and the compliment, Eric. Coolidge seems about the right geographic area for where I went, so maybe I did snap another structure. Maybe because I didn't fancy getting the roof in? I'm fussy like that!