Because it isn't clear:

There's one bird on this mural from each of the 243 taxonomic families. That's why there are a lot of unfamiliar species: because taxonomic categories are usually very unbalanced, with a lot which contain only a handful of species, and a few which contain the majority.

The birds on the mural are life-size. The ostrich is about 7.5 feet / 2.3m tall.

One question I have: what's the map projection?