February 14, 2019

Birds are Beautiful - Shapes (beaks)

February 14, 2019/ David Sparks

In the preface to The Sibley Guide to Birds (2000), David Sibley wrote “Birds are beautiful, in spectacular as well as subtle ways; their colors, shapes, actions, and sounds are among the most aesthetically pleasing in nature.” The “colors, shapes, actions” segment of this sentence inspired the organization of the photos to be included in my current photo book project. The images below (with a focus on the beak) are being considered for the Shape section of the book.

The bills or beaks of birds have adapted to the many different environments in which birds live. Once the forelimbs became devoted to wings and flight, the beaks had to serve functions performed by the forelimbs of most mammals - catching, carrying, cutting food, construction of nests, courtship, defending territory, preening and many other activities. A few of the variations in the bills of different species of birds are illustrated below.

Black-headed Grosbeak, Patagonia (AZ), April 2011
The Black-headed Grosbeak and the House Finch (below) have short, thick conical bills used for cracking seeds.

House Finch, Patagonia (AZ), April 2011

Wilson’s Warbler, Patagonia (AZ), April 2011
The thin, slender, pionted beaks of Wilson’s Warblers are used to pick insects off leaves, twigs, and bark.

Curve-billed Thrasher, El Paso County (CO), May 2018
The Curve-billed Thrasher forages on the ground beneath shrubs and cacti using the bill to spread plant litter while searching for seeds and insects.

Northern Shoveler, coastal TX, Jan. 2015
Ducks and geese have long and flat beaks that are used for straining water and mud for aquatic plants. The water filters through small comb-like structures lining the edges of the bill which can be seen in this image of the Northern Shoveler.

Red-breasted Merganser, Pensacola (FL), Jan. 2009
The sharp serrated tooth-like structures on the edge of the bill of Red-breasted Mergansers enable the bird to maintain a grip on struggling fish.

Ruppell’s Griffon Vulture, Tanzania, Feb. 2011
The sharply hooked bills of hawks, falcons, accipiters and vultures illustrated in the images of Ruppell’s Griffon Vulture and Crested Caracara (below) are effective in tearing apart the flesh of animals they consume. Note the hoofs of a zebra on the bottom right.

Crested Caracara, Viera Wetlands (FL), March 2012

Common Night Hawk, Anahuac NWR (TX), August 2016
Common Nighthawks have a bristle-fringed bill that sweeps in insects during flight.

Giant Petrel, Saint Andrews Bay, South Georgia Island, Dec. 2018

Except during the breeding season Giant Petrels spend almost all their time at sea. Cellular dehydration from drinking seawater does not occur because specialized glands filter salt ions from the bloodstream and excrete it as a highly concentrated saline solution that drips out of the external tubular nostril on top of the upper mandible.

Tricolored Heron, LA, May 2016
Tricolored and other herons and egrets have long bills which they use to make sudden, long jabs into the water for fish, frogs, crayfish, and snakes.

Black-necked Stilt, Bolivar Peninsula, (TX), August 2014
Black-necked Stilts have a long, thin, straight black bill which they use when probing in mud and sand for prey.

Marbled Godwit, Bolivar Peninsula, (TX), Oct. 2014
The Marbled Godwit has a long, up-turned bill used to probe with rapid head jabs in the mud.

Long-billed Curlew, Bolivar Peninsula (TX), Nov. 2013
Long-billed Curlews use their long, downcurved bills to reach deep into the water for mollusks and small crabs and to probe in the mud for worms and insects.

Western Grebe, Barr Lake State Park (CO), June 2016
Western Grebes and Anhinga (below) use their sharp, slender beaks to spear prey while diving in open water.

Anhinga, Wakodahatchee Wetlands (FL), Feb. 2015