[4] Microspathodon bairdii is endemic to the Eastern Pacific where its occurs from the mouth of the Gulf of California in Mexico south to Ecuador.

[1] Microspathodon bairdii occurs on rocky inshore reefs exposed to wave action and currents, being found down to 15 metres (49 ft).

In the Gulf of Chiriquí, Panamá, the bumphead damselfish is found among huge corals and exposed shallow rocky reefs.

[1] It is mainly herbivorous, feeding on algae, but will take a hook baited with animal matter[3] and will readily eat meat in the aquarium.

[3] The person that Gill was honouring with the specific name has not been identified but it is very probably Spencer Fullerton Baird who was director of the United States National Museum where the type specimen is located.