A Spoonbill Smorgasbord

A Spoonbill Smorgasbord

This blog post is a mix of some of my favorite photos of Roseate Spoonbills, a general description of the bird and its feeding behavior, clips of colorful sentences from the literature, and a summary of other things I found interesting while searching the web to learn more about this species.

High Island Smith Oak Rookery, High Island, TX - April 2017
Nikon D500, 500mm f/4 +1.4 tc, 1/3200 sec at f/9, ISO 720

Roseate Spoonbill (Platalea ajaja)

The roseate spoonbill is a large wading bird of the ibis and spoonbill family (Threskiornithidae). The body and the long legs are pink while the neck, breast and upper back are white. The adult bird has a bald, pale green head, a bright red shoulder patch and a long extremely flattened bill that is widened distally. The eyes are bright red. Juveniles have feathers on the regions of the head that are bald in adults and their pink feathers are lighter.

High Island Smith Oak Rookery, High Island, TX - March 2013
Nikon D7100, 300mm f/4 +1.4 tc, 1/4000 sec at f/8, ISO 640

The most distinctive feature of Platalea ajaja is the spoon-shaped bill. Over time, the beaks of birds adapted to the many different environments in which they live and once the forelimbs became devoted to flight, the beaks had to serve functions performed by the forelimbs of most mammals. This includes preening, manipulating objects, constructing nests, feeding young, courtship, defending territory, and acquiring and handling food. The size and structure of a bill is often directly related to species-specific feeding behaviors.

Spoonbill taking a bath - Jefferson Island Rookery, Abbeville, LA - April 2014
Nikon D7100, 500mm f/4 +1.4 tc, 1/2000 sec at f/8, ISO 720

The roseate spoonbill feeds in shallow water and forages by sweeping its open bill from side to side in the water to acquire food such as small fish, shrimp, mollusks, snails and insects. Some of the crustaceans it eats feed on algae that are the basis of the pigmentation that gives the feathers their pink color. The nostrils are at the top of the bill permitting the bird to breath while most of the bill is underwater. The wider distal part of the bill is similar to the bills of some ducks that sieve small prey out of sediments or water, but the bill of a spoonbill does not have the lamellae necessary for sieving (Allen, 1942). How, then, do spoonbills detect and capture its prey? Because the prey are not visible when the bird is feeding in murky water or in low light levels, senses other than vision must be involved. Insights into alternatives are based pimarily on studies in other species.

Bolivar Peninsula, TX -September 2019
Olympus E-M1 Mark II, 300mm f/4 + 1.4x tc, 1/2500 sec at f/5.6, ISO 640

Bolivar Peninsula, TX -September 2019
Olympus E-M1 Mark II, 300mm f/4 + 1.4x tc, 1/2500 sec at f/5.6, ISO 1250

“The birds of estuaries and mud flats are full of talk but the spoonbill is silent, and rarely even rattles his huge spoon. He feeds on the small molluscs, crustaceans and little flounders which swarm in the shallows and soft mud by a method so peculiar that it is small wonder that the gulls, in their humanlike distaste for the unfamiliar, sometimes harass and bully him. He wades through the water, and sweeps the great bill from side to side like the pendulum of a grandfather clock, tick-tock, dickery dock, swaying the body over the hips to keep the rhythm of the movement.”
From: Untrodden Ways - Harold John Massingham. Chapter V: The Spoonbill 1923

Roseate Spoonbill blog (24 of 1).jpg

Bolivar Peninsula, TX -September 2019
Olympus E-M1 Mark II, 300mm f/4 + 1.4x tc, 1/2500 sec at f/5.6, ISO 1000

Remote Touch

Shorebirds that feed by probing their long, thin bills into mud, sandy substrates or areas covered in water have numerous small cavities (pits) near the tip of their bills. The pits have high concentrations of Herbst and Grandry corpuscles, mechanoreceptors that respond to the movements of adjacent objects or fluids. These densely packed somatic receptors, known as ‘bill tip organs’, allow the bird to detect, and possibly identify, objects which are not visible. Thus, the shorebird's bill is viewed as not merely a structure for capturing, holding, and manipulating objects, but also as a ‘tactile exploratory organ’ (Martin 2018).

The bone of the upper bill tip of a Southern Brown Kiwi is shown below. The keratin sheath has been removed to reveal the numerous pits where clusters of touch receptors are housed.

Image taken from The Sensory Ecology of Birds by Graham R. Martin, Oxford University Press, 2017

Researchers use the phrase 'remote touch' to describe cases in which the bill tip does not need to make direct contact with an object in order to extract information about its presence in the mud, water, or sand that surrounds it. This could occur, for example, if the moving prey produced vibrations within the surrounding mud/sand/water or if the water displaced by the probing bill encountered a nearby object creating a detectable back pressure (Piersma et al. 1998).

Sanibel Island, FL - February 2012
Nikon D300, 300mm f/2.8 + 2x tc, 1/2000 sec at f/9, ISO 500

The external events that activate the receptors in the bill tip organs, the transduction of those physical events into electrical signals that are transmitted to the central nervous system, the nature of the signals generated by the receptors, and the central processing of the signals that permit the bird to detect and capture the prey are unknown or poorly understood.

Jefferson Island Rookery, Abbeville, LA - May 2013
Nikon D7100, 300mm f/2.8 + 1.7x tc, 1/3200 sec at f/8, ISO 800

How do we know that this remote sensing is based on somatosensory signals rather than olfactory or taste cues?

Anatomical studies reveal large numbers of Herbst corpuscles in the pits on the bony tips of the bill of red knots (Calidris canutus). In operant conditioning experiments (Piersma et al., 1998) red knots were able to distinguish buckets containing only wet sand from buckets of wet sand containing either deeply buried live bivalves or stones similar in shape to the bivalves. It seems unlikely that visual, acoustic, olfactory, gustatory, vibrational, temperature, or electromagnetic cues could be used to discriminate between the buckets that contained only wet sand and those that were filled with wet sand and a stone. The birds were not able to discriminate between containers filled with dry sand and those with bivalves covered with dry sand, indicating that the interstitial water in the wet sand is an important factor in the detection process. Hypotheses about the physiological processes involved in detection include the possibility that the rapid movements of the knots bill in the wet sand at the observed frequency of about 10 HZ generates a wave that is reflected back to the bill tip organs. The experiments required to test hypotheses about the physiological processes involved in detecting and decoding remote sensing signals would be extremely challenging technically. Imagine, as a first step, trying to record the electrical potentials generated by the receptors in the bill tip organs while the red knot is making repeated probes into the sand or while the bill of the spoonbill is being swept back and forth.

Jefferson Island Rookery, Abbeville, LA - April 2009
Nikon D300, 300mm f/4 + 1.7x tc, 1/2500 sec at f/6.7, ISO 800

While considered to be tactile feeders, the structure and function of mechanoreceptors in the bill of roseate spoonbill and their role in feeding behavior has received little scientific attention. In their paper describing the basic morphological features of the bill and the alimentary tract of Black-faced Spoonbill, Swennen and Yu (2004) described the layout and distribution of numerous pits observed in the skeletons of spoonbills. The pits are large enough to accommodate a series of Herbst corpuscles similar to what is observed in shorebirds. Although it seems highly likely that the pits in the beak of spoonbills are filled with mechanoreceptors, I could not find an article that verified this histologically.

Jefferson Island Rookery, Abbeville, LA - April 2010
Nikon D300, 500mm f/4 , 1/1250 sec at f/8, ISO 640

Visual Adaptations

As with the somatosensory system, over time, the visual system of birds has also adapted to the many different environments in which they live. One area of active research is concerned with how variations in visual field topography among birds is related to the foraging behavior of the different species (Martin & Portugal, 2011). The visual field of an eye is defined as the volume of external space which is imaged upon the retina when the eye is stationary and in the middle of the orbit. The combination of the visual fields of both eyes is called the cyclopean visual field and this defines the complete region of the external world at a particular instant in time from which visual information can be obtained when the eyes and head are in particular locations. The regions where the visual fields of both eyes overlap is the binocular field. In humans, our most precise perceptions of the relative depth of objects (stereopsis) is obtained from neural computations based on the subtly different views which each eye has of the same scene.

Jefferson Island Rookery, Abbeville, LA - May 2013
Nikon D7100, 300mm f/2.8 + 1.7x tc, 1/2500 sec at f/9, ISO 800

Why is the size and layout of the visual field of an animal of interest to the biologist? Basically, the visual field defines the region of the world in which visual stimuli can affect the behavior of the animal. Most birds have laterally placed eyes that provide a large field of view with the region of binocular overlap as well as the blind area behind and above the head being relatively small (middle graph below). Since most birds are also potential prey to many animals, including other birds, the large visual fields, resulting from the laterally placed eyes, allow large sectors of the environment to be monitored continuously for predators, potential prey, and other things of importance to the animal. Highly predatory birds such as eagles and owls have frontally placed eyes and excellent binocular vision but this is associated with a large blind area above and behind the head (see left graph below).

The eyes of Woodcocks are large and placed high in the skull. This provides visual coverage in which there is no blind area above or behind the head (see the graph on the right). As their bills probe into soft substrates for earthworms or other invertebrates, tactile and/or chemical cues are used to detect and capture their prey. Since woodcocks feed, roost and nest exclusively on the ground, they are always vulnerable to both aerial and terrestrial predators. Martin (1994) suggests that, freed from the constraint that vision is essential for location of prey or for precise control of bill position, visual fields have become primarily adapted for surveillance of the birds' environment.

Bolivar Peninsula, TX - August 2016
Nikon D500, 500mm f/4 + 1.4x tc, 1/1250 sec at f/6.3, ISO 640

Back to the spoonbill!!

Martin & Portugal (2011) predicted that since their foraging and feeding is guided by tactile cues from the bill, the visual fields of ibises and spoonbills would be similar to those of the woodcock and have comprehensive visual coverage of the celestial hemisphere. However, they found that the visual fields of the four species of ibis (2) and spoonbills (2) they tested had large blind areas above and behind the head. The spoonbills also had a blind area below the enlarged spatulate tip of the bill. Given the ability of spoonbills to forage successfully in highly turbid water using their bill-sweeping technique (Swennen & Yu 2005, 2008), seeing the bill and beneath it is not critical for prey detection and capture. How, then, does one explain the failure to confirm the prediction? The authors suggest that the identification of prey after its capture and possibly the transport of prey from the bill tip into the oesophagus requires visual representation of the space in which the bill resides.

Jefferson Island Rookery, Abbeville, LA - April 2009
Nikon D300, 300mm f/4 + 1.7x tc, 1/2500 sec at f/6.7, ISO 800

“If things, again, are not beautiful because they are rare, too many things are rare because they are beautiful, not through nature being sparing of her gold, but man so prodigal in spending it.”

The quote is from the book Untrodden Ways written in 1923 by Harold John Massingham. In this way, he introduced a description of the last account of the Eurasian Spoonbill breeding in England. He quotes Sir Thomas Browne who wrote in 1662: “They come in March and are shot by fowlers, not for their meat, but for the handsomenesse of the same, remarkable in their white colour, copped crowne and spoone, or spatule-like bill.”


Jefferson Island Rookery, Abbeville, LA - May 2016
Nikon D500, 500mm f/4, 1/3200 sec at f/7.1, ISO 1600

"This beautiful, large, and gregarious bird was nearly hunted to extinction in the last part of the 19th century. Its pink feathers were used in ladies' hats, and its wings were sold as fans. By 1939, about 30 birds remained in Florida. Interestingly, the spoonbill's pink plumage quickly fades once the feathers are no longer attached to a living bird. The good news is Roseate Spoonbills have made a comeback and currently have many champions monitoring and advocating for them, particularly the Gulf Restoration Network and Audubon of Florida. Now over a thousand pairs nest in Florida where they are stable along the Gulf Coast, yet still sinking in numbers in the broad estuary between the Everglades and the Keys." Quote from Shelley Hesse, an artist who lives in New Orleans. I found the quote below an image of her painting of a Roseate Spoonbill. Click on this link to see the image.

Jefferson Island Rookery, Abbeville, LA - April 2010
Nikon D300, 300mm f/4 + 1.4x tc, 1/5000 sec at f/7.1, ISO 320

The quotes are from the book Wings Over the Wetlands: Wading Birds in Louisiana. A PDF version of the book can be viewed by clicking on the link to the right. LINK

“Nicknamed the “Cajun Flamingo” by some Louisiana birders because of the plethora of “flamingo” reports which pour in each summer from uninitiated observers, the Roseate Spoonbill is actually a very close relative of the ibises.”

Note: Three hurricanes have made landfall in LA this year (2020). Strong winds and flooding have affected several of the regions mentioned in the report on the breeding status of the Roseate Spoonbill given below.

“The United States Gulf Rim, from south Texas eastward intermittently to south Florida, represents the northernmost breeding range for this primarily tropical species. Nevertheless, post-breeding wanderers have shocked bird-watchers as far north and west as Utah, Nebraska, and Pennsylvania. Just after the early 20th century harvest by plume hunters, the Roseate Spoonbill’s United States breeding range had shrunk to but a few isolated/protected coastal haunts in Texas, Louisiana, and Florida. These few colonies managed to survive until the mid 20th century when the United States Fish & Wildlife Service began to actively acquire more coastal lands for its National Wildlife Refuge Program. Today, the outlook for this species in the United States is considerably brighter. In Louisiana, according to the 2000 Louisiana Breeding Bird Atlas, breeding Roseate Spoonbills have been identified in no less than 18 mixed wading bird rookeries spread over 9 Louisiana parishes, including some as far inland as Evangeline, St. Landry, and Iberville Parishes.”


Jefferson Island Rookery, Abbeville, LA - April 2009
Nikon D300, 300mm f/4 + 1.7x tc, 1/2000 sec at f/8, ISO 800

“The long neck and bill were stretched out taut like a duck's, and the line was held straight through out, the rigidly extended legs being on the same level with the shapely body, so that the balance, with the body tapering to the neck in one direction and the tail and legs at the other, and with the thicknesses of the feet and widened tip of the bill at each end, was perfect.”

From: Untrodden Ways - Harold John Massingham, Chapter V: The Spoonbill - 1923

“They are like huge flowers, with wings! nearly three feet tall, with a long wingspan of more than four feet 1.2 m. skinny red legs, bright pink wings, and long white necks. no feathers on their greenish heads, and their eyes are a glowing red.”

From: Roseate Spoonbill: Pretty In Pink. by Stephen Person, 2013.

This is a photo of Plumeria, a genus of eleven species of shrubs and small trees in the dogbane family (Apocynaceae) native to tropical America from Brazil to Mexico and the Caribbean. The image is one I copied from a free source on the web. Why is the photo in this blog entry? When I was searching for information about spoonbills, I stumbled upon this article: Plumerias the Color of Roseate Spoonbills’ - Continuity and transition in the symbolism of Plumeria L. in Mesoamerica. Thomas J. Zumbroich. Ethnobotany Research & Applications 11: 341-363 (2013). From the abstract: “This study explores the complex symbolism which the genus Plumeria L. engendered from around the beginning of the common era to the present time in Mesoamerica. In much of this cultural area an intense interest in sensory pleasures can be traced to great antiquity, and, consequently, flowers became a central metaphor in the Mesoamerican cosmological discourse. In the Maya pantheon, plumeria was associated with deities representing life force and fertility and therefore plumeria flowers became strongly connected with a wide range of expressions of female sexuality. Among Nahuatl speaking people of central Mexico, especially during the height of the Aztec empire, the most prominent association of plumeria was to signify élite status, with plumeria trees planted in the gardens of the nobility, the blooms ex-changed at feasts, or the stylized image of plumeria flowers inscribed on ceramics and codices. In the context of the hybridized religious systems that developed in response to the introduction of Christianity across Mesoamerica, plumerias developed new meanings, e.g., as elaborate decorations for the worship of the Virgin Mary. When in the sixteenth century plumeria was dispersed beyond the Americas into Southeast Asia, likely through Spanish hands and by way of the Philippines, it gained a wide- spread association with graveyards as a plant promoting contact with the deceased.”

On page 348 I found the link to the spoonbill.

“In the 1570’s Francisco Hernández, court physician to King Philip II of Spain, set out on a scientific expedition to the Valley of Mexico with the objective of compiling a ‘Pliny of the New World’, and in the resulting monumental work more details about cacaloxochitl emerged. Hernández, too, recognized the wide range of different ‘raven flower’ plants that came in named varieties which only differed in the colors of their flowers, from crimson (tlapalticacaloxochitl, tlapaltic, ‘deep red’ (Sahagún 1950-1982:(7)) to white (iztaccacaloxochitl, iztac, ‘white’ (Molina 1571:f49r). In fact, there were so many that Hernández would not dare mention them all, so as not to bore the reader (Hernández 1615:45r-45v, Varey 2000:125-126). One particularly interesting plumeria variety received a separate entry: tlauhquecholtic was named for its similarity to the roseate spoonbill (Platalea ajaja L., 1758), an attractive wading bird with coloring from white through pink to magenta on its body).”


Merritt Island NWR, FL - January 2016
Nikon D4, 500mm f/4, 1/1000 sec at f/5, ISO 500

Merritt Island NWR, FL - January 2016
Nikon D4, 500mm f/4, 1/1000 sec at f/5, ISO 220

Merritt Island NWR, FL - January 2016
Nikon D4, 500mm f/4 + 1.4x tc, 1/2500 sec at f/5.6, ISO 1800

Merritt Island NWR, FL - January 2016
Nikon D4, 500mm f/4, 1/2500 sec at f/5, ISO 1000

Merritt Island NWR, FL - January 2016
Nikon D4, 500mm f/4, 1/2500 sec at f/5, ISO 500

Merritt Island NWR, FL - January 2016
Nikon D4, 500mm f/4, 1/2500 sec at f/5, ISO 500

Papers mentioned in the text

Allen, R.P. 1942. The Roseate Spoonbill. National Audubon Society, New York.

Birkhead, Tim. 2013. Bird senses: Vision. A Bird's Eye View. New Scientist. 3 August.

Massingham, Harold John. 1923. Untrodden Ways. Chapter V: The Spoonbill

Martin, Graham R. 2018. The Senses. Chapter 12 in Ornithology: Foundation, Analysis, and Application. edited by Michael L. Morrison, Amanda D. Rodewald, Gary Voelker, Melanie R. Colón, Jonathan F. Prather.

Martin,Graham R. 2017. The Sensory Ecology of Birds, Oxford University Press.

Martin, G. R., and Portugal, S. J. 2011. Differences in foraging ecology determine
variation in visual field in ibises and spoonbills (Threskiornithidae). Ibis 153, 662–671.

Martin G. R. 1994. Form and function in the optical structure of bird eyes. In: Davies MNO, Green PR (eds) Perception and motor control in birds: an ecological approach. Springer, Berlin Heidelberg New York, pp 5–34.

Person, Stephen. 2013. Roseate Spoonbill: Pretty In Pink. New York, NY: Bearport Publishing Company.

T. Piersma, R. van Aelst, K. Kurk, H. Berkhoudt, and L. R. M. Maas. 1998. A new pressure sensory mechanism for prey detection in birds: the use of principles of seabed dynamics? Proc. R. Soc. Lond. B 265, 1377-1383.

Swennen, C. and Yu, Yat-Tung. 2004. Notes on feeding structures of the Black-faced Spoonbill Platalea minor. Ornithological Science 3: 119-124.

Swennen, C. & Yu, Yat-Tung. 2005. Food and Feeding Behavior of the Black-faced Spoonbill. Waterbirds 28(1): 19-27.

Zumbroich, Thomas J. 2013. Plumerias the Color of Roseate Spoonbills’ - Continuity and transition in the symbolism of Plumeria L. in Mesoamerica. . Ethnobotany Research & Applications 11: 341-363.

David Sparks

I retired in 2005 after 40 years of research and teaching at the University of Alabama in Birmingham (24 years), the University of Pennsylvania (8 years) and the Baylor College of Medicine (8 years). Photography is my retirement hobby.

Nature photography, especially bird photography, combines a number of things that I really enjoy: bird-watching, being outdoors, photography, travel, messing about with computers, and learning new skills and concepts.  I now spend much of my time engaged in these activities.

David Sibley in the preface to The Sibley Guide to Birds 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."  My goal is to acquire images that capture the beauty and uniqueness of selected species as well as images that highlight the engaging behaviors the birds exhibit.