Anyone who really knows me will tell you I LLLLOOOOVVVEEEE penguins (to hear me actually say this, check out my birthday vlog, it's my first ever). They are my animal. So, of course my birthday Daily Doodle (the first of 366 doodles) has to be about penguins. Part of the fun of this project will be deciding which source I can "trust" and will use for my information to pass to you.
For example, the very first Google result says there are 17 penguin species, however, this is from kidszone.com ... hate to judge a site by it's domain, but I'm going to look at a few other sites before deciding that's it.
Sure enough, there are several other sites who are saying there are more or less than 17... but according to Antarctica.gov.au the Northern Rockhopper penguin and the Southern Rockhopper penguin can't cross breed, therefore giving them each their own species... this makes sense to me, so this is the source I chose to use from my Daily Doodle, and 18 species of penguins it is!