List of Sphenisciformes by population

16 (89% of total species) have had their population estimated: those missing are the king and little penguins, both of which have been assessed as being of least concern.

[4] Most maritime surveys use strip transect and distance sampling to measure density; this is then extrapolated over the animal's range.

The 2012 observation of 721 birds showed that levels have remained the same over recent years, and the current full estimate need not be changed.

Species that can no longer be included in a list of this nature include the Waitaha penguin, the last of which is believed to have perished between 1300 and 1500 AD (soon after the Polynesian arrival to New Zealand), and the Chatham penguin, which is only known through subfossils but may have been kept in captivity sometime between 1867 and 1872.

[7][8] Adélies and emperors nest on Antarctica and feed on broken pack ice; global warming's effect on the latter may affect their numbers, and the chinstraps and gentoo, which both feed in open waters, have been making inroads into the Adélie and emperors' formerly ice-packed range.