Bird Family Definition - Penguins

Macaroni Penguins
All penguins, such as macaroni penguins, belong to the Sphenicidae bird family. Photo © Liam Quinn/Flickr/CC by-SA 2.0


(noun) Spheniscidae is the scientific family of birds that is composed of all penguin species. Depending on how individual species are classified, the Spheniscidae family includes 17-18 bird species, 13 of which are considered vulnerable, threatened or endangered to varying degrees. Spheniscidae birds are almost exclusive to the Southern Hemisphere (one species, the Galapagos penguin, is found around the Equator), though the ranges of individual species vary widely.


(rhymes with "Sven is a guy" and "menace kid eye"

About Spheniscidae Birds

This bird family is one of the easiest to identify because penguins are such distinct and memorable birds. Their popularity in movies and literature makes penguins familiar even to non-birders, and many birders will note a penguin as their individual spark bird.

While there is a good deal of variation in different penguins' sizes and overall appearance, all birds in this scientific family share characteristics such as:

  • Flightless lifestyle with wings adapted as flippers for use in powerful, efficient swimming
  • Upright posture with short legs and feet set well back on the streamlined body
  • Dense, compact feather structure to provide superior insulation in cold climates
  • Pelagic lifestyle with much of the time spent in the water
  • Generally piscivorous diet that includes fish, squid, krill and similar marine prey
  • Black and white countershaded plumage coloration for effective camouflage in the water
  • Colonial behavior with large, communal nesting colonies reused for generations
  • Relatively long lifespans that may extend 15-20 years in the wild and longer in captivity

Past and Present Birds in the Spheniscidae Family

All penguins, and only penguin species, are part of this bird family.

There are 17-18 living penguin species currently recognized as distinct species. There is still debate about whether the northern rockhopper and southern rockhopper penguins are actually individual species, and the split between them is not yet universally recognized. The most familiar and well-known birds in the Spheniscidae family include the emperor penguin, king penguin and African penguin.

The number of penguins to have already gone extinct is constantly being refined and debated as more fossil evidence is uncovered and new but already extinct species are discovered. As many as 40 or more species of penguins may have gone extinct already, some through natural evolutionary processes and others through traumatic disasters or historic hunting and persecution. Today, the majority of penguin species - 13 different birds - are considered threatened, endangered or vulnerable to extinction if strong conservation measures are not taken for their protection. All penguins are legally protected, but poaching, pollution, irresponsible tourism, invasive predators, climate change and other threats are all severe hazards dramatically impacting penguin populations.

Genetic analysis has shown that a number of birds are closely related to penguins, but their closest living relatives are a surprise.

At first glance, it would seem that puffins, murres and auks would be close penguin relatives, and these birds do share many physical characteristics, including plumage coloration, upright posture and general diet. They are not, however, closely related in genetic terms.

While previous study has shown that petrels, albatrosses, frigatebirds, loons and grebes are all marginally related to penguins, the closest genetic relative to these birds is actually the storks, family Ciconiidae. Further studies of DNA and other genetic material from both living penguins as well as fossil remnants will be necessary to confirm and further explore the relationships between penguins and other bird families.

Where to See Spheniscidae Birds

Penguins are popular target birds for many birders, and travel to add penguins to a life list is always a popular type of avitourism.

There are dedicated tours and cruises to see penguins, and birders can visit these birds' native ranges in South America, Africa, Australia, New Zealand and the Galapagos Islands.

For birders whose time, budgets and lifestyle may not permit extensive travel to far-flung destinations, it is still possible to get up close and personal with penguins. These birds are popular additions to aquariums and zoos with prominent marine life exhibits, and several penguin species do very well in captivity and are part of dedicated captive breeding programs. While captive penguins are not typically countable on a competitive life list, interactive events and penguin meet-and-greet programs can be special opportunities for birders of all experience levels to enjoy.