Here are 8 birds that cant fly according to:

1. Penguin
2. Steamer duck
3. Weka
4. Ostrich
5. Kiwi
6. Kakapo
7. Takahe
8. Cassowary

And here are 10 birds that cant fly according to:

1. Kakapo
2. Ostrich
3. Emu
4. Kiwi
5. Takahe
6. Inaccessible Island Rail
7. Flightless Cormorant
8. Weka
9. Rhea
10. Cassowary

According to, flightless birds still have wings, but their wings are typically smaller or less fully developed than birds that fly. Feather shapes may be different, look fluffy like fur, they are tiny and compact and used for insulation while swimming. Birds that dont fly usually have fewer wing bones, or the bones may be fused, making the wings much less mobile than is needed for flying. Most flightless birds are missing the keel of the breastbone, the part of the bone that attaches to flight muscles.

In summary, there are several birds that cant fly due to their physical characteristics, such as smaller wings or fewer wing bones. Some examples of flightless birds include penguins, ostriches, kiwis, and cassowaries.