The

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Sulidae comprises the

gannet Gannets are seabirds comprising the genus ''Morus'' in the family Sulidae, closely related to boobies. They are known as 'solan' or 'solan goose' in Scotland. A common misconception is that the Scottish name is 'guga' but this is the Gaelic n ...

s and boobies. Collectively called sulids, they are medium-large coastal

seabird Seabirds (also known as marine birds) are birds that are adaptation, adapted to life within the marine ecosystem, marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent ...

s that plunge-dive for

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

and similar

prey Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not ki ...

. The 10

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

in this family are often considered congeneric in older sources, placing all in the

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

''Sula''. However, ''Sula'' (true boobies) and ''Morus'' (gannets) can be distinguished via morphological,

behavioral Behavior (American English) or behaviour (British English) is the range of actions of individuals, organisms, systems or artificial entities in some environment. These systems can include other systems or organisms as well as the inanimate p ...

, and

DNA sequence A nucleic acid sequence is a succession of bases within the nucleotides forming alleles within a DNA (using GACT) or RNA (GACU) molecule. This succession is denoted by a series of a set of five different letters that indicate the order of the nu ...

characters. Abbott's booby (''Papasula'') is given its own genus, as it stands apart from both in these respects. It appears to be a distinct and ancient lineage, maybe closer to the gannets than to the true boobies.Kennedy, Martyn; Spencer, Hamish G. & Gray, Russell D. (1996): Hop, step and gape: do the social displays of the Pelecaniformes reflect phylogeny? ''Animal Behaviour'' 51(2): 273-291. (HTML abstract) Erratum: ''Animal Behaviour'' 51(5): 1197.

Description

Sulids measure about in length and have a wingspan around . They have long, narrow, and pointed wings, and a quite long, graduated, and rather lozenge-shaped tail whose outer feathers are shorter than the central ones. Their flight muscles are rather small to allow for the small

cross-section Cross section may refer to: * Cross section (geometry) ** Cross-sectional views in architecture and engineering 3D * Cross section (geology) * Cross section (electronics) * Radar cross section, measure of detectability * Cross section (physics) ...

required for plunge-diving, as an adaptive trade-off relative to some sacrifice in flight performance. Consequently, they are very

streamlined Streamlines, streaklines and pathlines are field lines in a fluid flow. They differ only when the flow changes with time, that is, when the flow is not steady flow, steady. Considering a velocity vector field in three-dimensional space in the f ...

, reducing drag, so their bodies are "

torpedo A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, such ...

-shaped" and somewhat flat.Nelson, J. Bryan (2003): Gannets and Boobies. ''In:'' Perrins, C. (ed.): ''The Firefly Encyclopedia of Birds'': 82–87. Firefly Books, Oxford. They have stout legs and webbed feet, with the web connecting all four toes. In some species, the webs are brightly colored and used in

courtship display A courtship display is a set of display behaviors in which an animal, usually a male, attempts to attract a mate; the mate exercises choice, so sexual selection acts on the display. These behaviors often include ritualized movement ("dances"), ...

s. The bill is usually conspicuously colored, long, deep at the base, and pointed, with saw-like edges. The upper mandible curves down slightly at the tip and can be moved upward to accept large prey. To keep water out during plunges, the nostrils enter into the bill rather than opening to the outside directly. The eyes are angled forward, and provide a wider field of

binocular vision Binocular vision is seeing with two eyes. The Field_of_view, field of view that can be surveyed with two eyes is greater than with one eye. To the extent that the visual fields of the two eyes overlap, #Depth, binocular depth can be perceived. Th ...

than in most other birds. Their

plumage Plumage () is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, there can b ...

is either all-white (or light brownish or greyish) with dark wingtips and (usually) tail, or at least some dark brown or black above with white underparts; gannets have a yellowish hue to their heads. The face usually has some sort of black markings, typically on the lores. Unlike their relatives (the

darter The darters, anhingas, or snakebirds are mainly tropical waterbirds in the family Anhingidae, which contains a single genus, ''Anhinga''. There are four living species, three of which are very common and widespread while the fourth is rarer and c ...

s and

cormorant Phalacrocoracidae is a family of approximately 40 species of aquatic birds commonly known as cormorants and shags. Several different classifications of the family have been proposed, but in 2021 the International Ornithologists' Union (IOU) ado ...

s), sulids have a well-developed preen gland whose waxy secretions they spread on their feathers for waterproofing and pest control. They

moult In biology, moulting (British English), or molting (American English), also known as sloughing, shedding, or in many invertebrates, ecdysis, is a process by which an animal casts off parts of its body to serve some beneficial purpose, either at ...

their tail feathers irregularly and the

flight feather Flight feathers (''Pennae volatus'') are the long, stiff, asymmetrically shaped, but symmetrically paired pennaceous feathers on the wings or tail of a bird; those on the wings are called remiges (), singular remex (), while those on the tai ...

s of their wings in stages, so that starting at the first moult, they always have some old feathers, some new ones, and some partly grown ones. Moult as a response to periods of stress has been recorded.

Distribution and ecology

The sulids are distributed mainly in

tropical The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

and

subtropical The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones immediately to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Ge ...

waters, but they, particularly gannets, are found in

temperate In geography, the temperate climates of Earth occur in the middle latitudes (approximately 23.5° to 66.5° N/S of the Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ran ...

regions, too. These birds are not truly

pelagic The pelagic zone consists of the water column of the open ocean and can be further divided into regions by depth. The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or water column between the sur ...

seabirds like the related

Procellariiformes Procellariiformes is an order (biology), order of seabirds that comprises four family (biology), families: the albatrosses, the Procellariidae, petrels and shearwaters, and two families of storm petrels. Formerly called Tubinares and still call ...

, and usually stay rather close to the coasts, but the abundant colonies of sulids that exist on many

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is bounded by the cont ...

islands suggest that they are not infrequently blown away from their home range by

storm A storm is any disturbed state of the natural environment or the atmosphere of an astronomical body. It may be marked by significant disruptions to normal conditions such as strong wind, tornadoes, hail, thunder and lightning (a thunderstor ...

s, and can wander for long distances in search of a safe place to land if need be. All

feed entirely at sea, mostly on mid-sized

and similarly sized marine

invertebrate Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate s ...

s (e.g.

cephalopod A cephalopod is any member of the molluscan Taxonomic rank, class Cephalopoda (Greek language, Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral symm ...

s). Many species feed communally, and some species follow

fishing boat A fishing vessel is a boat or ship used to catch fish and other valuable nektonic aquatic animals (e.g. shrimps/prawns, krills, coleoids, etc.) in the sea, lake or river. Humans have used different kinds of surface vessels in commercial, arti ...

s to

scavenge Scavengers are animals that consume dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a herbivorous feeding be ...

discarded

bycatch Bycatch (or by-catch), in the fishing industry, is a fish or other marine species that is caught unintentionally while fishing for specific species or sizes of wildlife. Bycatch is either the wrong species, the wrong sex, or is undersized or juve ...

and chum. The typical hunting behavior is a dive from midair, taking the bird a 1–2 m under water. If prey manages to escape the diving birds at first, they may give chase using their legs and wings for underwater swimming. As noted above, the

traits of gannets and boobies differ considerably, but the Sulidae as a whole are characterized by several behavioral synapomorphies: Before taking off, they point their bills upwards (gannets) or forward (boobies). After landing again, they point downwards with their bills. In response to a threat, they do not attack, but shake their heads and point their bills towards the intruders.

Reproduction

All sulids breed in

colonies A colony is a territory subject to a form of foreign rule, which rules the territory and its indigenous peoples separated from the foreign rulers, the colonizer, and their '' metropole'' (or "mother country"). This separated rule was often or ...

. Males examine the colony area in flight and then pick a nest site, which they defend by fighting and territorial displays. Males then advertise to females by a special display and call. Their display behavior is characteristic, though not as diverse as the numerous variations found among the

s; it typically includes the male shaking his head. Females search the colony in flight and on foot for a mate. Once they select males, pairs maintain their bonds by preening each other and by frequent copulation. The

clutch A clutch is a mechanical device that allows an output shaft to be disconnected from a rotating input shaft. The clutch's input shaft is typically attached to a motor, while the clutch's output shaft is connected to the mechanism that does th ...

is typically two eggs. The eggs are unmarked (but may become stained by

debris Debris (, ) is rubble, wreckage, ruins, litter and discarded waste, garbage/refuse/trash, scattered remains of something destroyed, or, as in geology, large rock fragments left by a melting glacier, etc. Depending on context, ''debris'' can ref ...

in the nest), whitish, pale blue, green, or pink, and have a coating that resembles lime. Egg weight ranges from 3.3 to 8.0% of the female's weight. Incubation lasts 42 to 55 days, depending on the species. Both sexes incubate; like their relatives, they do not have

brood patch A brood patch, also known as an incubation patch in older literature, is a patch of featherless skin on the underside of birds during the nesting season. Feathers act as inherent insulators and prevent efficient incubation, to which brood patches ...

es, but their feet become

vascular Vascular can refer to: * blood vessels, the vascular system in animals * vascular tissue Vascular tissue is a complex transporting tissue, formed of more than one cell type, found in vascular plants. The primary components of vascular tissue ...

ized and hot, and the birds place the eggs under the webs. Eggs lost during the first half of incubation are replaced. At hatching, parents move the eggs and then the hatchlings to the tops of their webs. The young hatch naked, but soon develop white down. They beg by touching the parent's bill and take regurgitated food straight from its gape. At first, at least one parent is always in attendance of the

altricial Precocial species in birds and mammals are those in which the young are relatively mature and mobile from the moment of birth or hatching. They are normally nidifugous, meaning that they leave the nest shortly after birth or hatching. Altricial ...

young; after two weeks, both parents leave the nest unguarded at times while they go fishing. The times for the chicks to fledge and become independent of their parents depend greatly on the food supply. Rarely does more than one chick survive to maturity, except in the Peruvian booby (''Sula variegata''), which has the biggest clutch (two to four eggs), and less often in the

blue-footed booby The blue-footed booby (''Sula nebouxii'') is a marine bird native to subtropical and tropical regions of the eastern Pacific Ocean. It is one of six species of the genus ''booby, Sula'' – known as boobies. It is easily recognizable by its dis ...

(''S. nebouxii'').

Siblicide Siblicide (attributed by behavioural ecologist Doug Mock to Barbara M. Braun) is the killing of an infant individual by its close relatives (full or half siblings). It may occur directly between siblings or be mediated by the parents, and is dr ...

by the stronger of two chicks is frequent.

Systematics and evolution

Sulids are related to a number of other aquatic birds, which all lack external

nostril A nostril (or naris , : nares ) is either of the two orifices of the nose. They enable the entry and exit of air and other gasses through the nasal cavities. In birds and mammals, they contain branched bones or cartilages called turbinates ...

s and a

, but have all four toes webbed and a gular sac. The closest living relatives of the Sulidae are the Phalacrocoracidae (cormorants and shags) and the Anhingidae (darters). The latter are somewhat intermediate between sulids and cormorants, but (like many cormorants) they are

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include non-salty mi ...

birds in a

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

containing otherwise

s, and also symplesiomorphic with sulids but synapomorphic with cormorants in some other respects. Thus, the Sulidae seem to be the oldest and most distinct lineage of those three, which are united in a

suborder Order () is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and recognized ...

Sulae. Therein, the Sulidae are typically placed simply as a

; sometimes, a superfamily Suloidea is recognized, wherein some of the primitive prehistoric forms (e.g. '' Empheresula'', '' Eostega'', and '' Masillastega'') are placed as basal lineages distinct from the living Sulidae. However, the proposed family Pseudosulidae (or Enkurosulidae) is almost certainly invalid. Olson, Storrs L. (1985): Section X.G.5.a. Sulidae. ''In:'' The Fossil Record of Birds. ''Avian Biology'' 8: 203-204
PDF fulltext
/ref> Christidis, Les & Boles, Walter E. (2008): ''Systematics and Taxonomy of Australian Birds''. CSIRO Publishing, CollingwoodVictoria, Australia.
Excerpt
at

Google Books Google Books (previously known as Google Book Search, Google Print, and by its code-name Project Ocean) is a service from Google that searches the full text of books and magazines that Google has scanned, converted to text using optical charac ...

p.100Mayr, Gerald (2009): 7.1.3 Sulidae (Gannets and Boobies). ''In: Paleogene Fossil Birds'': 64-65. Springer-Verlag, Heidelberg & New York.
Excerpt
at

The Sulae were traditionally included in the Pelecaniformes in its obsolete

paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

circumscription, but

pelican Pelicans (genus ''Pelecanus'') are a genus of large water birds that make up the family Pelecanidae. They are characterized by a long beak and a large throat pouch used for catching prey and draining water from the scooped-up contents before ...

s, the namesake family of the Pelecaniformes, are actually more closely related to

heron Herons are long-legged, long-necked, freshwater and coastal birds in the family Ardeidae, with 75 recognised species, some of which are referred to as egrets or bitterns rather than herons. Members of the genus ''Botaurus'' are referred to as bi ...

s, ibises and spoonbills, the

hamerkop The hamerkop (''Scopus umbretta'') is a medium-sized bird. It is the only living species in the genus ''Scopus (bird), Scopus'' and the family (biology), family Scopidae. The species and family was long thought to sit with the Ciconiiformes but ...

, and the

shoebill The shoebill (''Balaeniceps rex''), also known as the whale-headed stork, and shoe-billed stork, is a large long-legged wading bird. It derives its name from its enormous shoe-shaped bill. It has a somewhat stork-like overall form and has pre ...

than to the sulids and allies. In recognition of this, the Sulae have been proposed for separation in a new

order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...

Phalacrocoraciformes, which also includes the

frigatebird Frigatebirds are a Family (biology), family of seabirds called Fregatidae which are found across all tropical and subtropical oceans. The five extant species are classified in a single genus, ''Fregata''. All have predominantly black plumage, l ...

s (Fregatidae), as well as one or more

prehistoric Prehistory, also called pre-literary history, is the period of human history between the first known use of stone tools by hominins million years ago and the beginning of recorded history with the invention of writing systems. The use o ...

lineages that are entirely

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

today. The IOC World Bird List uses Suliformes as the proposed order name. Within the family itself, three living genera—'' Sula'' (boobies, six species), '' Papasula'' (Abbott's booby), and '' Morus'' (gannets, three species)—are recognized. A 2011 study of multiple genes found Abbott's booby to be basal to all other gannets and boobies, and likely to have diverged from them around 22 million years ago, and the ancestors of the gannets and remaining boobies split around 17 million years ago. The most recent common ancestor of all boobies lived in the late Miocene around 6 million years ago, after which time the boobies steadily diverged. The gannets split more recently, only around 2.5 million years ago. The

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

record of sulids is quite extensive due to the many

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

, and all things (such as the

Early Eocene In the geologic timescale the Ypresian is the oldest age (geology), age or lowest stage (stratigraphy), stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by th ...

'' Limnofregata'') considered, the sulids seem to have diverged from the lineage leading to cormorants and darters around 50 million years ago (Mya), perhaps a bit earlier. The initial

evolutionary radiation An evolutionary radiation is an increase in taxonomic diversity that is caused by elevated rates of speciation, that may or may not be associated with an increase in morphological disparity. A significantly large and diverse radiation within ...

formed a number of

genera Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...

that are now completely extinct, such as the

'' Masillastega'' (which, as noted above, might not have been a modern-type sulid) or the bizarre '' Rhamphastosula'' (which had a bill shaped like an aracari's). The modern genera

evolved Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, re ...

(like many other living genera of birds) around the

Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

-Miocene boundary about 23 Mya. '' Microsula'', which lived during that time, seems to have been a primitive booby that still had many symplesiomorphies with gannets. Like the other Phalacrocoraciformes, the sulids originated probably in the general region of the

Atlantic The Atlantic Ocean is the second largest of the world's five oceanic divisions, with an area of about . It covers approximately 17% of Earth's surface and about 24% of its water surface area. During the Age of Discovery, it was known for se ...

or western

Tethys Sea The Tethys Ocean ( ; ), also called the Tethys Sea or the Neo-Tethys, was a prehistoric ocean during much of the Mesozoic Era and early-mid Cenozoic Era. It was the predecessor to the modern Indian Ocean, the Mediterranean Sea, and the Eurasia ...

– probably the latter rather than the former, given that their earliest fossils are abundant in

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

, but absent from the well-studied contemporary

America The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

n deposits. Prehistoric sulids (or suloids) only known from

s are: * '' Masillastega'' (Early Eocene of Messel, Germany) – may belong in ''Eostega'' * '' Eostega'' (Late Eocene of Cluj-Manastur, Romania) – may include ''Masillastega'' * Sulidae gen. et sp. indet. (Thalberg Late Oligocene of Germany) – ''Empheresula''? * Sulidae gen. et sp. indet. (Late Oligocene of South Carolina, United States) – ''Microsula''? * '' Empheresula'' (Late Oligocene of Gannat, France – Middle Miocene of Steinheimer Becken, Germany) – including ''"Sula" arvernensis'', ''"Parasula"'' * '' Microsula'' (Late Oligocene of South Carolina, United States – Grund Middle Miocene of Austria) – may belong in ''Morus'' or ''Sula'', includes ''"Sula" avita'', ''"S." pygmaea'', ''Enkurosula'', ''"Pseudosula"'' * '' Sarmatosula'' (Middle Miocene of Credinţa, Romania) * '' Miosula'' (Late Miocene of California) * '' Paleosula'' (Early Pliocene? of California) * '' Rhamphastosula'' (Pisco Early Pliocene of SC Peru) * '' Bimbisula'' (middle Pliocene of South Carolina) * Sulidae gen. et sp. indet. (Late Pliocene of Valle di Fine, Italy) – ''Morus''?A

proximal Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...

humerus The humerus (; : humeri) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius (bone), radius and ulna, and consists of three sections. The humeral upper extrem ...

fragment somewhat similar to a gannet's: Lambrecht (1933: p.286) For prehistoric

of the extant

, see the genus articles. The

Early Oligocene The Rupelian is, in the geologic timescale, the older of two age (geology), ages or the lower of two stage (stratigraphy), stages of the Oligocene epoch (geology), Epoch/series (stratigraphy), Series. It spans the time between . It is preceded b ...

'' Prophalacrocorax ronzoni'' of Ronzon, France, was variously placed in the

seaduck The sea ducks (Mergini) are a tribe of the duck subfamily of birds, the Anatinae. The taxonomy of this group is incomplete. Some authorities separate the group as a subfamily, while others remove some genera. Most species within the group spend ...

genus ''

Mergus ''Mergus'' is the genus of the typical mergansers ( ) fish-eating ducks in the subfamily Anatinae. The genus name is a Latin word used by Pliny the Elder and other Ancient Rome, Roman authors to refer to an unspecified waterbird. The common mer ...

'', in ''Sula'', and after a distinct genus was established for it, in the Phalacrocoracidae. While it is quite likely to belong in the Sulae and may have been an ancient sulid (or suloid), of the three placements explicitly proposed, none seems to be correct.Göhlich, Ursula B. (2003): The avifauna of the Grund Beds (Middle Miocene, Early Badenian, northern Austria). ''Annalen des Naturhistorischen Museums Wien A'' 104: 237-249 nglish with German abstractbr>PDF fulltext
/ref>

References

External links

Live camera from Eldey IcelandSulidae videos
on the Internet Bird Collection

{{Authority control Bird families Taxa named by Ludwig Reichenbach Extant Ypresian first appearances