Birds are an incredibly diverse animal group. This is reflected in every aspect of their anatomy, as you can see in this short list of facts about the bodies of birds.
Size
Tallest bird – Ostrich at 9 ft (2.7 m)
Smallest bird – Bee Hummingbird at 2.24 inches (5.7 cm)
Legs
Longest legs – Ostrich
Longest legs relative to body length – Black-necked Stilt at 9 inches (23 cm), which is 60% of its height.
Shortest legs – virtually non-existent in Swifts
Longest toes relative to body length – Northern Jacana at 4 inches (10 cm)
Bill
Longest bill – Australian Pelican at 18.5 inches (47 cm)
Longest bill relative to body length – Swordtailed Hummingbird at 4.13 inches (10.5 cm)
Shortest bill – Glossy Swiftlet, at just a few tenths of an inch
Largest and fleshiest tongue – Flamingo.
Longest tongue relative to body size – Wryneck (at two-thirds of its body length, excluding the tail)
Feathers
Greatest number of feathers – Whistling Swan with 25,216
Lowest number of feathers – Ruby-throated Hummingbird with 940
Source of these facts: The Bird Almanac, by Dr. David M. Bird