Charadriomorpha: Pelecaniformes, Charadriiformes, & Allies

Large (0.4-2.0 m), fish-eating shore or sea birds. Long bill; pseudo-teeth in several extinct forms; several forms with intramandibular joint and other gnathal kinesis adaptations for large prey; frequently aberrant nares, including reduced or absent nares and very long, slit-like nares; large salt gland within orbit; gular pouches common, used in hunting and in cooling behaviors; legs moderate to short; totipalmate feet, with hallux (I) partially turned and webbed to II; bones extensively pneumatized, and connected with respiratory system; subdermal air sacs also known in some cushions ariel diving?); swimming, skimming and ariel diving hunters, some foot-propelled divers; cooperative hunting (driving) of fish; migrations uncommon; breeding always in isolated areas and very sensitive to mammalian predation; multi-year pairing and nesting common; altricial, naked young with sometimes very extended parental care by both parents.

Tube-nosed sea birds. Bills short to medium, with distinctive hooked terminal nail; tubular nostrils; wings typically long, with very high aspect ratio except in smaller, diving forms; larger forms frequently require wind, altitude or long runway to take off; legs shifted posteriorly; poor walkers & may use wings as props; usually only on land for breeding; feet webbed, with hallux reduced or absent; plumage never bright; stomach oils from enlarged and folded proventriculus, rich in vitamins A & D; oil used in feeding young, as feather waterproofing, or as defense; prey on pelagic crustaceans and squid; many species nocturnal; colonial breeding in isolated locations; very low reproductive rate with high investment in rearing young; altricial young with slow maturation; very long lived. Possibly polyphyletic group, ancestral to Sphenisciformes.

Large (60-100 cm) Arctic foot-propelled divers. Strong, tapered bill; small, pointed wings; legs placed far posterior and upper leg merges with body (convergent on hesperornithiforms and gruiformes); 3 webbed toes; bones not pneumatic; coloration mainly blacks, greys and whites; dive up to 60m; fast flyers; feed on fish and other medium-sized aquatic animals; solitary except during migration (if any); nest on vegetation adjacent to water; precocial young.

Underwater flyers from the Southern Hemisphere, 35 cm & 1kg to 120 cm and 40 kg. Nostrils slit-like, but tubular in some young; salt glands; legs far back on body; closely fused tarsal elements; plantigrade; elaborate temperature control mechanisms in feet; bones not pneumatic; no apteria; feathers have long aftershaft of down and tips for oily, waterproof coating; may make 200+ dives per day, larger species to 16 min and 500 m depth; feed on krill (compete with whales) and fish; some are nocturnal; attacked by seals; frequently return to same mate and site; mating cycle once or less per year; usually lay 1-3 eggs; biparental care (alternate); high mortality among eggs; raised in crèche, but individually fed; young independent in 2-12 months.

Fairly unspecialized land birds. Small head; bill short and may be overhung by fleshy operculum; palatines do not meet at the midline; vomer vestigial or absent; schizorhinal; 14-15 cervical vertebrae; large pectoral muscles; sternum with large lateral incisions; U-shaped furculum with weak hypocleideum; wings medium to short; 11 primaries; body compact; legs short; grain, seed and fruit eaters, with many ground-feeding forms; crop used for food storage; $ able to drink continuously (rather than tipping head between sips) with esophogeal contractions; fairly high rate of reproduction compared to sea birds, with high juvenile mortality from starvation; $ secretion from crop wall for young convergent on mammalian milk.

Noisy, bright-colored tropical birds, 8 to 100 cm, with strong, hooked beaks. Thick, hooked bill, usually with cutting surface on lower bill; highly rhynchokinetic upper jaw; short, flesh tongue highly mobile; cere (area of soft bare or sparsely-feathered skin) surrounding nostrils, frequently colored; short, thick neck; compact body; carina prominent; furcula highly variable; wings often pointed; feet sturdy; zygodactyl toes; entire foot with thick, lightly scaled skin; frequently able climbers and dexterous with feet; some flightless insular species; strongly monogamous; nest largely in holes in trees; usually gregarious; long history of semi-domestication; generally long-lived and intelligent.