Madagascar: Escape 2 Africa on GameCube?

No. Madagascar: Escape 2 Africa (2008) was never released on Nintendo GameCube.

The Timeline Reality

• GameCube Discontinued: June 2007 (Japan), November 2007 (Americas), early 2008 (Europe).
• Madagascar 2 Release: November 2008 (movie tie-in).

The console was dead a year before the game launched. Activision (publisher) targeted active platforms only.

Platforms It Did Release On

• Wii (lead SKU)
• PlayStation 2 (huge install base lingered)
• PlayStation 3
• Xbox 360
• PC
• Nintendo DS (distinct 2D version)

The Only Madagascar on GameCube

Madagascar (2005) — Based on the first movie. Released on GC, PS2, Xbox, DS, GBA. This is the one you're remembering.

If You Want to Play Madagascar 2 Today

• Wii Version: Best console experience. Motion controls for minigames. Plays on Wii U (backward compat) and Wii (obviously).
• PC (Steam/GOG?): Not currently on major stores. Check GOG or Steam periodically.
• Dolphin Emulator (PC/Android) — Run Wii/GC ISO. Wii version runs great. Requires legal dump of your disc.

No GC port exists. Don't waste time searching eBay for a fake "GameCube case" repro.