Okay quietkid, here's what the law has to say. You may be disappointed, though, because the law is often ambiguous and this case is a prime example.
Firstly, this is the legal description of hunting (in Ontario specifically):
“hunting” includes,
(a) lying in wait for, searching for, being on the trail of, pursuing, chasing or shooting at wildlife, whether or not the wildlife is killed, injured, captured or harassed, or
(b) capturing or harassing wildlife,
except that “hunting” does not include,
(c) trapping, or
(d) lying in wait for, searching for, being on the trail of or pursuing wildlife for a purpose other than attempting to kill, injure, capture or harass it, unless the wildlife is killed, injured, captured or harassed as a result,
and “hunt” and “hunter” have corresponding meanings; (“chasse”, “chasser”, “chasseur”)
This is the only comment about AGE in the legislation:
Age limit
64. (1) A licence shall not be issued to a person who is under 16 years of age.
And this is the part that, IMHO, you need to treat as the bible on the subject (because any CO can choose to consider participating in a hunting party as "hunting" under the legal definition - see above):
Hunter Apprenticeship Safety Program
The Hunter Apprenticeship Safety Program is designed to
enhance the existing Hunter Education Program by allowing
individuals the opportunity to safely develop their hunting
skills while under the direct and immediate supervision of a
qualified Mentor. Any Ontario resident who is 12 years of age
or older and who has successfully completed the Ontario
Hunter Education Course (OHEC) and exam is eligible to
participate. The Hunter Apprenticeship Safety Program is
mandatory for qualified participants under the age of 15 but
is optional for new hunters who are 15 years of age or over.
Hunter safety is an integral component of this program and
the following conditions apply to participants of the Hunter
Apprenticeship Safety Program:
1. Apprentice must be a resident of Ontario.
2. Written parental permission is required if the
Apprentice is 12 to 15 years of age.
3. Apprentice must successfully complete the Ontario
Hunter Education Course (OHEC) and pass the
examination.
4. Apprentice must carry a Hunter Apprenticeship Safety
Card while hunting.
5. Apprentice, while hunting, must be under the direct and
immediate supervision of a hunter (Mentor) who is 18
years of age or older and who holds a valid Outdoors
Card and licence to hunt the species of game being
hunted.
6. Apprentice must share a single firearm (gun, bow or
crossbow) with the Mentor.
7. If the species of game being hunted is wild turkey, the
Apprentice must have successfully completed the Wild
Turkey Education Course and exam.
8. If the species of game being hunted is a migratory game
bird, the Apprentice must be the holder of a Migratory
Game Bird Hunting Permit.
9. Any game (except for migratory birds) taken by the
Apprentice must be included in the bag limit of the
Mentor.
10. Apprenticeship is valid for up to three years and is not
renewable.
11. Mentor is responsible to ensure that the Apprentice
complies with the regulations while hunting under the
Mentor’s supervision.
For additional information on the Hunter Apprenticeship
Safety Program, contact an MNR office.
I hope this satisfies your need for an air-tight response on the subject, because you're not going to find anything more definite.
SS