Can I use Garrigues' Birds of Costa Rica as a portable field guide in Panama if I have Ridgely's Panama (too large to carry) FG available in the car and/or hotel room? Or are there too many birds that Panama and Costa Rica don't have in common? Is Van Perlo's illustrated checklist of Mexico and Central America a better choice even though the illustrations too many, are very small and not as good as Garriques'?