Just thought that this was interesting. The most popular first word/sign the children of deaf parents I have interviewed so far say that their baby's first word (or among there first words) is moose. MOOSE?!?!?!
One reason for this phenomenon is that the sign for moose is relatively easy and is perhaps the most basic gesture an infant can make. Infants have poor eyesight the first few months after birth and can only see close up (within 18 inches approximately) as well as only high contrasted images. For this reason parents are often up close and in their child's face, talking, cooing, playing, touching, etc. Among these activities the parents hands aren't tied behind their backs. Their hands are kinetic (in Deaf parents more so than Hearing parents).Put yourself in a situation (hypothetically) where you are asked to interact with an infant. Chances are you may very well bring your hands to your face and try on a few funny faces. This is perhaps the easiest way of describing why children sign moose early in their communicational development.
Secondly, because of the ease for signing moose, Deaf parents often incorporate it among other signs such as 'mom', 'dad', 'all done' and the manual alphabet (signed alphabet).
For future reference, I will include on my survey a question regarding the child's first word/sign.