ORIGINAL: bluebird2
All were aged by the lower jawbone
What method was used to judge the age of each buck. Simply referring to the lower jaw bone tells us nothing about the aging method.
Forgive me, I incorrectly assumed that you would understand the process. In case you ever harvest something over 6 months old these might come in handy. The system isn't perfect but it's reasonably accurate.
http://www.uwrf.edu/biology/electives_dir/wildlife_dir/aging_wtd_tooth_wear.pdf
http://www.timberwolfinformation.org/info/deerjaw/ages.htm
http://mdc.mo.gov/hunt/deer/age/