Nazca booby | |
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Adult on Española Island, Galapagos Islands | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Suliformes |
Family: | Sulidae |
Genus: | Sula |
Species: | S. granti |
Binomial name | |
Sula granti Rothschild, 1902 | |
The Nazca booby (Sula granti) is a large seabird of the booby family, Sulidae, native to the eastern Pacific. First described by Walter Rothschild in 1902, it was long considered a subspecies of the masked booby until recognised as distinct genetically and behaviorally in 2002. It has a typical sulid body shape, with a long pointed orange-yellow bill, long neck, aerodynamic body, long slender wings and pointed tail. The adult is bright white with black and white wings, a black tail and a dark face mask.
Walter Rothschild organised and sent an expedition to the Galapagos Islands in 1897 to collect and review the animal life there. He wrote of a distinctive booby there, which he and William Robert Ogilvie-Grant diagnosed as the Peruvian booby (Sula variegata), then only known from juvenile plumage. [2] Later, in 1902, Rothschild named it a new species, Sula granti. [3] Rothschild later reclassified as a subspecies of the masked booby. [4]
In 1998, Pitman and colleagues observed that Nazca boobies on Clipperton Island did not interbreed with masked boobies there. [5]
The genus Sula was previously placed in the order Pelecaniformes, but recently was collected in the family Sulidae and order Suliformes, together with 8 other genera. [6] The Nazca booby was considered conspecific with the masked booby but was reassigned to a separate species based on mitochondrial DNA analyses. It is likely to have diverged 400,000-500,000 years ago. [7]
The species has a yellow iris, orange and pinkish beak, black facial skin in the form of a mask, and grey feet. Adults present white plumage with black tips of the wings and tail. The female is bigger and heavier than the male, has a slightly differently colored beak, and squawks while the male whistles. Chicks are snow white and fluffy, plumage changing to grey along with beak and feet upon fledging. [8]
The species occurs in the eastern Pacific from the islands in Baja California to the Galápagos Islands and the Isla de la Plata in Ecuador and Malpelo in Colombia. [9] [10]
The Nazca booby preys on small fish caught by diving at high speed from flight into the ocean. The main food species is South American pilchard, but also take flying fish, anchovies and squid, especially during the El Niño events, when sardine numbers are low. [11] Because of their sexual dimorphism, females tend to feed on bigger prey and dive deeper. [12]
The Nazca booby nests near cliffs on bare ground with little to no vegetation. [7] The male chooses and defends a territory, then enters into courtship to attract females. [13]
Like many seabirds, the species has a long lifespan combined with low annual reproduction and long periods of development in the young. Clutch size is one or two eggs, due to the low hatching success, however when 2 eggs are laid and they both hatch, it is common for only one of the chicks to survive. [14] Usually, whichever is the first to hatch is the one that survives. [15]
While many species of birds regulate egg temperature via an incubation patch, a layer of bare skin that allows birds to transmit heat into their eggs, the Suliformes instead use the skin on their webbed feet in addition to heat transferred from the breast. The feet are heavily vascularized, especially during the nesting period. [16] Both the male and the female show parental care. [17] Usually the chick that hatches first is bigger and becomes aggressive towards its sibling, excluding it from feeding and eventually starving it. [14]
The energy investment on the parent's part is very high, so their metabolic rates change during the nesting season. This causes both parents to lose similar amounts of body weight and suffer a decline in their immune system activity. [17] This adjustment does not take place when the parents decide not to nest, a decision that is mostly driven by food availability, which in turn depends on ocean current and climate patterns such as those driven by the El Niño oscillation. [11]
Siblicide has been well studied in this species; the first chick is born around five days before the second and is larger and stronger by the time the second is born. It drags its younger sibling out of the nest. Field experiments in the Galapagos demonstrated that the boobies can manage to feed two chicks without too much difficulty. This raises questions as to the origin of the phenomenon. [18] [19]
The vampire ground finch sometimes feeds on the blood of the Nazca booby. [20]
The Nazca booby is classified as Least Concern by the IUCN. Although populations are thought to decrease to some extent, this decline is not strong enough to require classification in a threat category. Some of the factors that influence the decrease of populations are overfishing and marine pollution. [11] [21]
Frigatebirds are a 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, long, deeply forked tails and long hooked bills. Females have white underbellies and males have a distinctive red gular pouch, which they inflate during the breeding season to attract females. Their wings are long and pointed and can span up to 2.3 metres (7.5 ft), the largest wing area to body weight ratio of any bird.
A booby is a seabird in the genus Sula, part of the family Sulidae. Boobies are closely related to the gannets (Morus), which were formerly included in Sula.
The bird family Sulidae comprises the gannets and boobies. Collectively called sulids, they are medium-large coastal seabirds that plunge-dive for fish and similar prey. The 10 species in this family are often considered congeneric in older sources, placing all in the genus Sula. However, Sula and Morus (gannets) can be readily distinguished by morphological, behavioral, and DNA sequence 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.
The northern gannet is a seabird, the largest species of the gannet family, Sulidae. It is native to the coasts of the Atlantic Ocean, breeding in Western Europe and Northeastern North America. It is the largest seabird in the northern Atlantic. The sexes are similar in appearance. The adult northern gannet has a mainly white streamlined body with a long neck, and long and slender wings. It is 87–100 cm long with a 170–180 cm (67–71 in) wingspan. The head and nape have a buff tinge that is more prominent in breeding season, and the wings are edged with dark brown-black feathers. The long, pointed bill is blue-grey, contrasting with black, bare skin around the mouth and eyes. Juveniles are mostly grey-brown, becoming increasingly white in the five years it takes them to reach maturity.
The common murre, also called the common guillemot or foolish guillemot, is a large auk. It has a circumpolar distribution, occurring in low-Arctic and boreal waters in the North Atlantic and North Pacific. It spends most of its time at sea, only coming to land to breed on rocky cliff shores or islands.
The red-billed tropicbird is a tropicbird, one of three closely related species of seabird of tropical oceans. Superficially resembling a tern in appearance, it has mostly white plumage with some black markings on the wings and back, a black mask and, as its common name suggests, a red bill. Most adults have tail streamers that are about two times their body length, with those in males being generally longer than those in females. The red-billed tropicbird itself has three subspecies recognized, including the nominate. The subspecies mesonauta is distinguished from the nominate by the rosy tinge of its fresh plumage, and the subspecies indicus can be differentiated by its smaller size, more restricted mask, and more orange bill. This species ranges across the tropical Atlantic, eastern Pacific, and Indian Oceans. The nominate is found in the southern Atlantic Ocean, the subspecies indicus in the waters off of the Middle East and in the Indian Ocean, and the subspecies mesonauta in the eastern portions of both the Atlantic and the Pacific Oceans and in the Caribbean. It was one of the many species described by Carl Linnaeus in his 1758 10th edition of Systema Naturae.
The blue-footed booby is a marine bird native to subtropical and tropical regions of the eastern Pacific Ocean. It is one of six species of the genus Sula – known as boobies. It is easily recognizable by its distinctive bright blue feet, which is a sexually selected trait and a product of their diet. Males display their feet in an elaborate mating ritual by lifting them up and down while strutting before the female. The female is slightly larger than the male and can measure up to 90 cm (35 in) long with a wingspan up to 1.5 m (5 ft).
The brown booby is a large seabird of the booby family Sulidae, of which it is perhaps the most common and widespread species. It has a pantropical range, which overlaps with that of other booby species. The gregarious brown booby commutes and forages at low height over inshore waters. Flocks plunge-dive to take small fish, especially when these are driven near the surface by their predators. They nest only on the ground, and roost on solid objects rather than the water surface.
The red-footed booby is a large seabird of the booby family, Sulidae. Adults always have red feet, but the colour of the plumage varies. They are powerful and agile fliers, but they are clumsy in takeoffs and landings. They are found widely in the tropics, and breed colonially in coastal regions, especially islands. The species faces few natural or man-made threats, although its population is declining; it is considered to be a least-concern species by the International Union for Conservation of Nature (IUCN).
The great frigatebird is a large seabird in the frigatebird family. There are major nesting populations in the tropical Pacific Ocean, such as Hawaii and the Galápagos Islands; in the Indian Ocean, colonies can be found in the Seychelles and Mauritius, and there is a tiny population in the South Atlantic, mostly on and around St. Helena and Boatswain Bird Island.
The masked booby, also called the masked gannet or the blue-faced booby, is a large seabird of the booby and gannet family, Sulidae. First described by the French naturalist René-Primevère Lesson in 1831, the masked booby is one of six species of booby in the genus Sula. It has a typical sulid body shape, with a long pointed yellowish bill, long neck, aerodynamic body, long slender wings and pointed tail. The adult is bright white with black wings, a black tail and a dark face mask; at 75–85 cm (30–33 in) long, it is the largest species of booby. The sexes have similar plumage. This species ranges across tropical oceans, except in the eastern Atlantic and eastern Pacific. In the latter, it is replaced by the Nazca booby, which was formerly regarded as a subspecies of masked booby.
The swallow-tailed gull is an equatorial seabird in the gull family, Laridae. It is the only species in the genus Creagrus, which derives from the Latin Creagra and the Greek kreourgos which means butcher, also from kreas, meat; according to Jobling it would mean "hook for meat" referring to the hooked bill of this species. It was first described by French naturalist and surgeon Adolphe-Simon Neboux in 1846. Its scientific name is originally derived from the Greek word for gull, "Glaros" and via Latin Larus, "gull" and furca "two-tined fork". It spends most of its life flying and hunting over the open ocean. The main breeding location is in the Galápagos Islands, particularly the rocky shores and cliffs of Hood, Tower and Wolf Islands, with lower numbers on most of the other islands. It is more common on the eastern islands where the water is warmer.
Siblicide is the killing of an infant individual by its close relatives. It may occur directly between siblings or be mediated by the parents, and is driven by the direct fitness benefits to the perpetrator and sometimes its parents. Siblicide has mainly, but not only, been observed in birds.
Regurgitation is the expulsion of material from the pharynx, or esophagus, usually characterized by the presence of undigested food or blood.
The Peruvian booby is an endemic bird of the Peruvian current, and an important predator of the marine community to which it belongs. Its distribution is much less widespread than other closely related booby species. It is the most abundant seabird species that inhabits the Peruvian coast and the second most important guano-producing seabird. During the mid-twentieth century, the Peruvian booby population reached 3 million birds.
Abbott's booby is an endangered seabird of the sulid family, which includes gannets and boobies. It is a large booby and is placed within its own monotypic genus. It was first identified from a specimen collected by William Louis Abbott, who discovered it on Assumption Island in 1892.
The magnificent frigatebird is a seabird of the frigatebird family Fregatidae. With a length of 89–114 centimetres and wingspan of 2.17–2.44 m it is the largest species of frigatebird. It occurs over tropical and subtropical waters off America, between northern Mexico and Perú on the Pacific coast and between Florida and southern Brazil along the Atlantic coast. There are also populations on the Galápagos Islands in the Pacific and the Cape Verde islands in the Atlantic.
The term seabird is used for many families of birds in several orders that spend the majority of their lives at sea. Seabirds make up some, if not all, of the families in the following orders: Procellariiformes, Sphenisciformes, Pelecaniformes, and Charadriiformes. Many seabirds remain at sea for several consecutive years at a time, without ever seeing land. Breeding is the central purpose for seabirds to visit land. The breeding period is usually extremely protracted in many seabirds and may last over a year in some of the larger albatrosses; this is in stark contrast with passerine birds. Seabirds nest in single or mixed-species colonies of varying densities, mainly on offshore islands devoid of terrestrial predators. However, seabirds exhibit many unusual breeding behaviors during all stages of the reproductive cycle that are not extensively reported outside of the primary scientific literature.
The order Suliformes is an order recognised by the International Ornithologist's Union. Regarding the recent evidence that the traditional Pelecaniformes is polyphyletic, it has been suggested that the group be divided to reflect the true evolutionary relationships; a 2017 study indicated that they are most closely related to Otidiformes (bustards) and Ciconiiformes (storks).
Brood reduction occurs when the number of nestlings in a birds brood is reduced, usually because there is a limited amount of resources available. It can occur directly via infanticide, or indirectly via competition over resources between siblings. Avian parents often produce more offspring than they can care for, resulting in the death of some of the nestlings. Brood reduction was originally described by David Lack in his brood-reduction hypothesis to explain the existence of hatching asynchrony in many bird species.