Investigating the Peak
Speak to Charlie at the Ardougne Zoo, who will tell you he needs help getting a ferret for a new attraction at the zoo. He tells you that his associate Nickolaus is searching for ferrets at Eagles' Peak, west of the Tree Gnome Stronghold.
If you have access to fairy rings, the code AKQ will take you to the Piscatoris Hunter Area directly north of the abandoned campground. If you have completed the Grand Tree and Tree Gnome Village, you can use the Spirit Tree just west of the zoo to quickly travel to the Tree Gnome Stronghold.
Travel to the Tree Gnome Stronghold, then follow the fence northwest from the outside until you reach the path leading up the Eagles' Peak. If you have level 25 Agility, follow the path to the top, then use the Agility shortcut to reach the abandoned, ferret-infested camp. If you do not have the Agility requirement, travel to the north around the peak.
Inspect the books near the tent, and read the acquired Bird book to get a Metal feather. The book's entry on the Giant Eagle describes a hidden nest at the top of the mountain. Travel to top of the peak and use the metal feather on the rocky outcrop, then enter through the cave entrance.
Getting the costume
Once inside, grab the Feathered journal on the ground and head south until you come across Nickolaus, trapped in a Giant Eagle's nest. He is excited about his discovery, but admits he has become trapped. He needs a disguise to get past the giant eagle, and suggests you ask the Fancy Dress Shop owner in Varrock. Before you leave, take 10 giant eagle feathers from the piles nearby.
The Fancy Dress Shop is located in the gated area just south of the Varrock east bank. Speak with the owner and select "Well, specifically I'm after a couple of bird costumes." He will tell you he needs 10 giant eagle feathers, swamp tar, and yellow dye to create the costumes. Speak with him again with all the materials, and he will give you two eagle costumes for 50 gold.
Take the costumes back to the Eagles' Peak and head further south in the dungeon until you discover a large stone door. You will need to collect four metal feathers to get past this door.
Collecting the metal feathers
Go through the tunnel entrance directly west, and you will see a bronze feather sitting on a pedestal. Try to grab the feather and it will be snatched up in a net. Operate the winches at each of the four corners of the room, and the pedestal will be lowered. Take the Bronze feather.
Exit the room and head north, into another tunnel entrance. Inspect the empty pedestal and a set of tracks will appear. Like tracking for the hunter skill, you will need to inspect adjacent piles of rocks to find out which path the creature has taken. Eventually the tracks will point to an opening. Inspect the opening and a level 13 Kebbit will jump out. It will drop the Silver feather after being defeated. (If you lose the feather, you can get another by inspecting the opening, and you will not have to fight the kebbit again)
Exit the room and head northeast into the final tunnel entrance (not to be confused with the cave exit). When you enter, take 5 Odd bird seed from the birdseed holder at the entrance. Refer to the following map. If at any point you are stuck, exit the room and pull the reset lever next to the entrance.
- Pull down lever 1
- Place birdseed into feeder B1, then feeder B2.
- Pull lever 2
- Push up lever 1
- Place birdseed into Feeder A1
- Place birdseed into Feeder C2.
- Pull lever 3
- Pull lever 4
- Put birdseed into C3, then into C2
After following these steps, the path to the gold feather is clear. Use the bronze, silver, and gold feathers on the stone door, and you are able to open it. Equip your Eagle cape and fake beak, then click the Giant Eagle to sneak past it. Talk to Nickolaus to give him the spare costume, then head outside and down to Nickolaus' campground.
Nickolaus will teach you how to catch ferrets using a box trap, then give you a ferret to take back to Charlie. Charlie will add the ferret to the newest exhibit of the zoo, and the quest is complete.