Build your trap. Then build a small hut with a generator and a fridge. If you solo go to highlands with a flyer and find mutton. It's good in the birds inventory for 40 mins. Be sure to also have raw meat so your bird doesn't eat the mutton. Mutton is good for 40 minutes on your inventory and 8 hours in the fridge.
If your Griffin has les than 3000hp above lvl 120 then you have to use darts. Also best way to tranq them with a crossbow is shoot and when it says tranq arrow has been consumed wait for it to dissappear then shoot