Morphology and Taxonomy

Due to the fact that Charadriiformes is one of the most diverse orders that there is, it is only natural to try to split them up to make sense of all the variety.  Formerly, Charadriiformes were classified into three suborders Charadrii (waders), Lari (gulls), and Alcae (auks).  Today, due to molecular evidence the three suborders have been rearranged into Lari, Scolopaci, and Charadrii.  With this change auks and the buttonquial are now grouped with Lari.  The plains-wanderer has now been grouped with Scolopaci, and the Egyptian Plover is now grouped with Charadrii.

Charadriiformes Taxonomy

Lari are alike for the most part in that they are all grouped together by their methods of diving.  They are all adapted to feeding by either swooping down or diving down into the water to catch their prey.  Skuas and Gulls dive down to either bully others into giving them their food or by retrieving food by gathering it from the water.  Skimmers skim the top of the water using their bottom bill to gather food, and auks dive down underneath the water completely to hunt.  To be able to hunt fish or crabs, most have slightly hooked or razor-like bills to stab their prey.  This allows them to hang onto fish while they grab them from the water.  Most also have shorter legs with webbed feet to aid them while swimming or moving around in the water.

Foot of a Gull

Hooked Bill of a Skua

Scolopaci are alike in the sense that they are all waders.  Most are found around swamps, marshes, lowlands, and any areas that involves shallow water.  Like Lari, the suborder Scolopaci is known for its bill; however, they do not take on a curved or hooked shape.  Instead, the bills of Scolopaci are usually long narrow and pointed.  This helps members like the sandpiper and snipes to be able to eat insects and crustaceans, and for jacanas to be able to pick out aquatic insects and vegetation as well as seeds.  The legs of Scolopaci are generally longer than those of Lari due to the fact they when standing in low pools of water, they prefer to keep their feathers from getting soaked.  Also since these birds are no adapted for swimming, their feet are generally not webbed; instead they have three long toes with one in the back making an Anisodactyl formation.

A Solitary Sandpiper Wading in the Water

Anisodactyl Formation on an African Jacana

The suborder Charadrii is the most diverse out of the three.  They make up a large group of waders similar to Scolopaci.  Stilts and Avocets have the longest legs out of this suborder along with webbed feet.  They are able to do some swimming but stilts rarely do.  The ibisbill has partially webbed feet taking on the Syndactyl formation, but it is much easier to identify due to its really distinct long crimson colored down-curved bill.  The oystercatcher also has relatively long legs, but it is better known for its long orange or red bill that it uses to pry open mollusks.  These birds along with sheathbills and most plovers who have shorter legs and bills usually occupy habitats that are surrounded by water.  Thick-knees and stone-curlews however tend to occupy more arid climates of savannas and grasslands.  They are known for their plumages which give them the appearance of a reptile and take on a nocturnal lifestyle.

Ibisbill

The Yellow Eye of the Stone-Curlew Resembles A Reptile

References

Roberson, Don. "Bird Families of the World, 11th Ed." Bird Families of the World, 11th Ed. N.p., 31 Mar. 2012. Web. 12 June 2012. <http://creagrus.home.montereybay.com/list.html>.

Rouse, Greg W. "Tree of Life Web Project." Tree of Life Web Project. N.p., 2001. Web. 12 June 2012. <http://tolweb.org/tree/phylogeny.html>.