Northern Mockingbirds with no tails

A Northern Mockingbird without a tail, Riparian Preserve, Gilbert, AZ; 12/26/2011.

Last winter was the second time that I saw a Mockingbird without a tail (Above). This time a Northern Mockingbird at the Riparian Preserve at Water Ranch in Gilbert, AZ. The first time I saw a tailless Mockingbird (a Tropical Mockingbird, I believe) was at a boat marina near Cancun, Mexico, in December of 2010.  (See my blog post http://northernillinoisbirder.blogspot.com/2011/01/tropical-mockingbird-northern.html ).

A nice rear view of no tail on this N. Mockingbird, Riparian Preserve, Gilbert, AZ; 12/26/2011.

I also had an anonymous reader, Marie, from the East Coast send me the following message on March 22, 2011:
     Anonymous said...

"You are the only one that talks about a tailless mockingbird. The past 3 days, we have had one feeding at our feeder. My picture is poor, due to lack of telephoto lens, but I am curious if this bird is just passing by or will stay for the season. We are in the tristate area of Delaware, Maryland, and Pennsylvania. Marie "

I know that these three incidents are probably purely coincidental, but it's fun to make some wild conjectures:
          1. There is a species of Mockingbirds that have no tails, that no one in the ornithological world
               has acknowledged.
          2. The N. Mockingbird that I saw last December, is the same one that Marie saw on the
              East Coast in March of 2011, and perhaps the same one I saw in Mexico but misidentified it
              as a tropical Mockingbird.
          3. All Mockingbirds go through a phase in which they lose their tail feathers and they regrow.
         
Well, as it turns out, I am not the only person who has mentioned tailless Mockingbirds. Below are links to other sites I've located on the Internet that either refer to Mockingbirds without tails and/or have photos:
http://nature.gardenweb.com/forums/load/bird/msg0717252417284.html?16

http://travel.webshots.com/photo/2415289540011412446ApDSyP

http://www.idigmygarden.com/forums/archive/index.php/t-19790.html (Read 4th entry down)

http://forums.photographyreview.com/nature-wildlife/extremely-rare-tail-less-variant-agelaius-phoeniceus-56102.html (Scroll down to the 6th entry)

http://www.freelists.org/post/birdky/tailless-Mockingbird

A Northern Mockingbird with its tail intact, Phoenix, AZ; 12/25/2009.

A more likely scenario about why Mockingbirds lose their tails could be, because Mockingbirds are bolder and more curious than the average bird and their tails are long (Above) compared to their shorter wings that...
     1.  it is easier for their tails to get caught in something and the feathers get pulled out ...
     2.  or get caught by a predator (a house cat or fox, etc.) which grabs a hold of the tail,
         but the bird escapes leaving its tail behind (no pun intended).
Other causes could be ...
     3. genetic in nature, where some key ingredient of the DNA is missing that causes a bird to be
         hatched without a tail ( I am no scientist, so I don't know if I even stated that correctly),
     4. or from some sort of parasite that infested the nest while the bird was being fledged.

Have fun with your own theories.