Basic Expert: Falconry is a Charisma based skill

Falconry is the employment of a sentient predator to hunt food prey.

We should regard this as a Charisma based skill in which the Morale of the retainer (in this case the Falcon) is checked to see if it abandons its Master.

Monsters have morale so if the retainer Morale (thanks to Player Character's charisma) is below this falconry is impossible.
So the Charisma of anyone employing falconry should be 9+.

Because it's charisma based, its usable by any class character with sufficient charisma.

In D&D terms we can use the standard Normal Hawk for Stats. of our Falcon.

                                   Normal
                                    Hawk       
Armor Class:                 8
Hit Dice:                       1/2
Move:                   
      flying:               480' (160')
Attacks:                         1
Damage:                       1-2
No. Appearing:        0 (1-6)
Save As:                 Normal Man
Morale:                          7
Treasure Type:            Nil
Alignment:               Neutral

Ex. Ming Ming (Human fighter, Cha 16) gets a +1 on any falconry checks such as when her male falcon catches the scent of a female and decides not to return to his Mistress but fly off into the sunset.

Cha      Adjust to   Max. No.    Morale of
Score  Reactions  Retainers    Retainers
 3              -2                    1                4
 4-5           -1                   2                 5
 6-8           -1                   3                 6
 9-12         0                    4                 7
 13-15      +1                   5                 8
 16-17      +1                   6                 9
 18            +2                   7                10