California river penguin (Porgotopsis Ligantii) is a species of penguin and the only one of the genus Porgotopsis. They are one of the only species of penguin adapted to freshwater life instead of ocean and among the only penguin species, apart from Galapagos penguins, to be found in the Northern hemisphere. Despite their appearance similar to a crestless version of a rockhopper penguin (other than being brown instead of black), their closest living relatives are actually penguins of the genus Spheniscus. They are mostly carnivorous and feeds off of mollusks, crustaceans, fish, frogs, lizards, snakes, pond turtles, smaller birds, and small mammals, but can sometimes feed on fruits and mushrooms to supplement their diet, though they have evolved the ability to feed on man-made food in a same manner as seagulls. Adults weigh on average 2.2–3.5 kg (4.9–7.7 lb) and are 60–70 cm (24–28 in) tall. They are very social water birds and can live in colonies up to about 150 in a single area. They build nests and even protect and raise their own young (both unhatched and hatched) in a similar manner to African penguins.
Fortunately, unlike most other penguins, this species of penguin can readily adapt well into an urban and suburban environments in their native range, being able to tolerate habitat loss, pollution, competition for food, etc. Unlike most other penguin species, California river penguin populations are actually increasing and flourishing due to newer habitats to exploit (going under people's homes as homes and nesting grounds, for example) and abundance of food. Because of this, the International Union for Conservation of Nature (IUCN) was listed as being Least Concern.
Unlike most penguins, this penguin species adapts really well as household pets due to the river penguin's docile nature, more favored behavior towards pet owners (not defecating often in houses, not being noisy all the time, etc), and more varied diet, so this is the easiest species of penguin to keep as pets and is legalized as pets in most states of the United States (even in California).