[O] searching properties, not tags

[Christopher W. Ryan]

>From what I have seen, most of the org-mode manual documentation about
searching or matching tags and properties is about the former, rather
than the latter. How would I search out all the headlines that have a
property of a certain value?  For example:

** Tigger
   :PROPERTIES:
   :species:  tiger
   :color:    striped
   :clothing: none
   :END:
** Eeyore
   :PROPERTIES:
   :species:  donkey
   :color:    grey
   :clothing: none
   :END:
** Winnie The Pooh
   :PROPERTIES:
   :species:  bear
   :color:    yellow
   :clothing: red shirt
   :END:

How would I search for all the tigers?

Thanks.

--Chris Ryan