The New Zealand king shag (''Leucocarbo carunculatus''), also known as the rough-faced shag, king shag or kawau pāteketeke, is a rare bird
endemic
Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...
to
New Zealand
New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...
. Some taxonomic authorities, including the
International Ornithologists' Union
The International Ornithologists' Union (IOU) is an international organization for the promotion of ornithology
Ornithology, from Ancient Greek ὄρνις (''órnis''), meaning "bird", and -logy from λόγος (''lógos''), meaning "study", ...
, place this species in the genus ''
Leucocarbo''. Others place it in the genus ''
Phalacrocorax
''Phalacrocorax'' is a genus of fish-eating birds in the cormorant family Phalacrocoracidae. Members of this genus are also known as the Old World cormorants.
Taxonomy
The genus ''Phalacrocorax'' was introduced by the French zoologist Mathurin ...
''.
Taxonomy
The New Zealand king shag was
formally described in 1789 by the
German
German(s) may refer to:
* Germany, the country of the Germans and German things
**Germania (Roman era)
* Germans, citizens of Germany, people of German ancestry, or native speakers of the German language
** For citizenship in Germany, see also Ge ...
naturalist
Johann Friedrich Gmelin
Johann Friedrich Gmelin (8 August 1748 – 1 November 1804) was a German natural history, naturalist, chemist, botanist, entomologist, herpetologist, and malacologist.
Education
Johann Friedrich Gmelin was born as the eldest son of Philipp F ...
in his revised and expanded edition of
Carl Linnaeus
Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...
's ''
Systema Naturae
' (originally in Latin written ' with the Orthographic ligature, ligature æ) is one of the major works of the Sweden, Swedish botanist, zoologist and physician Carl Linnaeus (1707–1778) and introduced the Linnaean taxonomy. Although the syste ...
''. He placed it 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 ...
''
Pelecanus'' and coined the
binomial name
In taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, altho ...
''Pelecanus carunculatus''. Gmelin based his description on the "carunculated shag" that had been described in 1785 by the English ornithologist
John Latham in his book ''A General Synopsis of Birds ''. Latham had based his description on a specimen in the
Leverian Museum. The New Zealand king shag is now one of 16 species placed in the genus ''
Leucocarbo'' that was introduced in 1856 by the
French naturalist
Charles Lucien Bonaparte
Charles Lucien Jules Laurent Bonaparte, 2nd Prince of Canino and Musignano (24 May 1803 – 29 July 1857) was a French naturalist and ornithology, ornithologist, and a nephew of Napoleon. Lucien and his wife had twelve children, including Cardinal ...
.
The name ''Leucocarbo'' combines the
Ancient Greek
Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...
''leukos'' meaning "white" with the genus name ''Carbo'' introduced by
Bernard Germain de Lacépède
Bernard-Germain-Étienne de La Ville-sur-Illon, comte de Lacépède or La Cépède (; 26 December 17566 October 1825) was a French natural history, naturalist and an active freemason. He is known for his contribution to the Comte de Buffon's g ...
in 1799. The specific epithet is from
Latin
Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...
''caruncula '' meaning "small piece of flesh". The species is
monotypic
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ...
: no
subspecies
In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...
are recognised.
[
]
Description
It is a large (76 cm long, 2.5 kg in weight) black and white 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 ...
with pink feet. White patches on the wings appear as bars when the wings are folded. Yellow-orange swellings ( caruncles) are found above the base of the bill. The grey gular pouch is reddish in the breeding season. A blue eye-ring indicates its kinship with the other blue-eyed shag
''Leucocarbo'' is a genus of birds in the family Phalacrocoracidae. Several species within the genus are collectively known as blue-eyed shags. This is a group of closely related cormorant taxa. Many have a blue, purple or red ring around the eye ...
s. They show sexual dimorphism
Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...
, with males being larger than females. This difference is noticeable as early as 17 days after hatching.
Distribution and habitat
New Zealand king shags can be seen from the Cook Strait ferries in Queen Charlotte Sound opposite the beginning of the Tory Channel
Tory Channel (officially Tory Channel / Kura Te Au) is one of the drowned valleys that form the Marlborough Sounds in New Zealand. Inter-island ferry, ferries normally use it as the principal channel between Cook Strait and the Marlborough Sound ...
. Prehistorically, the king shag lived on coastal colonies on both the North Island and South Island of New Zealand. Today, they live and breed in the coastal waters of the Marlborough Sounds
The Marlborough Sounds (Māori language, te reo Māori: ''Te Tauihu-o-te-Waka'') are an extensive network of ria, sea-drowned valleys at the northern end of the South Island of New Zealand. The Marlborough Sounds were created by a combination ...
at nine colonies that are occupied year-round. King shags are non-migratory birds, with their only dispersal being between colonies. They are found at Stewart Island, Trio Island, The Twins, Duffers Reef, Blumine Island
Blumine Island / is an island in the outer reaches of Queen Charlotte Sound / Tōtaranui, in the Marlborough Sounds at the northern end of New Zealand's South Island.
The New Zealand Ministry for Culture and Heritage gives a translation of "m ...
, Tawhitinui, Hunia Rock, Rahuinui, and White Rocks. The most commonly observed breeding colonies are Duffers Reef, North Trio Island (Kuru Pongi), White Rocks, and Tawhitinui. Annual surveys show fluctuating numbers of breeding pair nests at the colonies. North Trios (Kuru Pongi) and Duffer's Reef are the largest colonies, with over 100 nests apiece. The estimated population of king shags is 792, as of 2022.
Behaviour
Breeding
The king shag breeding season spans from February to April, with eggs being laid as late as May. They are considered asynchronous breeders because the time of breeding is dependent on the colony the bird is in, rather than internal cues only. King shags show strong nesting site fidelity
Fidelity is the quality of faithfulness or loyalty. Its original meaning regarded duty in a broader sense than the related concept of '' fealty''. Both derive from the Latin word , meaning "faithful or loyal". In the City of London financial m ...
, returning to the same colony to breed on repeated years. They also have high mate fidelity, with monogamous
Monogamy ( ) is a relationship of two individuals in which they form a mutual and exclusive intimate partnership. Having only one partner at any one time, whether for life or serial monogamy, contrasts with various forms of non-monogamy (e.g. ...
, experienced pairs being the most successful. Clutches are 2-3 eggs. They do not consistently lay one egg right after another. Up to 13 days can pass between eggs. If the clutch is damaged or the chicks do not survive, it is rare for replacement clutches to be laid. The eggs incubate for 28–32 days before hatching. After 6 weeks, the chicks reach adult body mass, and after 8 weeks are fully feathered.
Parental care lasts, on average, 21 weeks. This is measured from the last feeding of the chick. One parent remains at the nest at all times, while the other forages. Both males and females take turns being the caregiver and hunter. Juveniles begin to disperse from their nests anywhere from 4–12 months after hatching. King shags experience high levels of juvenile mortality, especially shortly after dispersal. After one year, an estimated 54% of juveniles died. Other species of cormorants experience similar levels of juvenile mortality. The level of parental care strongly impacts the survival rate of juveniles, with longer parental care increasing the chances of survival. Colony location can also increase juvenile survival. Colonies on the outer edge of the Marlborough Sounds saw higher mortality rates, likely due to lack of shelter against weather.
Feeding
King shags feed by diving to catch benthic
The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from the Ancient Greek word (), meaning "the depths". ...
fish. These dives are 25–40 metres deep on average, but have been recorded as deep as 90 metres. On average, a king shag can dive for between one and three minutes. Each dive is separated by a period of rest before diving again. These last, on average, 157 seconds but can span up to 12 minutes. Individual king shags show a wide range in variation of diving durations and depths. Males and females show significantly different diving behaviour. Female king shags dive at 8–62 metres depth, and a majority of dives are done before 1 pm. Male king shags dive at a wider range of depths, 8–71 metres, and hunt later in the day, with a majority of dives occurring after 12 pm. Due to the increased depth, male king shags tend to dive for longer durations than females. Different colonies have different diving behaviours due to the different marine geology in the Marlborough Sounds. Male king shags tend to travel further from the colony to forage, but this relies heavily on the location of the colonies. Blue-eyed shags ('' Leucocarbo'') are highly individualistic foragers, and the king shag follows this pattern. The foraging range of king shags is highly dependent on the colony where they reside. King shags can forage anywhere from 8-24 kilometres away from their colonies. There is a significant difference in distance travelled between the sexes in the Tawhitinui, The Twins, and Duffers Reef colonies, with males travelling further.
The most prevalent prey of king shags are witch
Witchcraft is the use of magic by a person called a witch. Traditionally, "witchcraft" means the use of magic to inflict supernatural harm or misfortune on others, and this remains the most common and widespread meaning. According to ''Enc ...
(''Pleuronectidae
Pleuronectidae, also known as righteye flounders, are a family of flounders. They are called "righteye flounders" because most species lie on the sea bottom on their left sides, with both eyes on their right sides. The Paralichthyidae are the o ...
'') and crested flounder (''Bothidae
Bothidae or lefteye flounders are a family of flounders. They are called "lefteye flounders" because most species lie on the sea bottom on their right sides, with both eyes on their left sides. The family is also distinguished by the presence of ...
''). These are both flatfish
A flatfish is a member of the Ray-finned fish, ray-finned demersal fish Order (biology), suborder Pleuronectoidei, also called the Heterosomata. In many species, both eyes lie on one side of the head, one or the other migrating through or around ...
, and reside on the floor of the ocean. King shags typically consume their prey underwater, but there have been multiple observations of individuals surfacing carrying flatfish. King shags also feed on opalfish, lemon sole
The lemon sole (''Microstomus kitt'') is a flatfish of the family Pleuronectidae. It is native to shallow seas around Northern Europe, where it lives on stony bottoms down to depths of about . It grows up to in length and reaches about in weigh ...
, and smooth leatherjacket most commonly. Smooth leatherjackets are one of the few 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 ...
fish found in many king shag pellets. Remnants of octopus, crab, and lobster have been found within the pellets of king shags, but it is unlikely that the birds consume them directly. Instead, it is thought to be the stomach contents of the fish eaten, and thus be a secondary dietary item. Compared with other cormorants, the king shag has a reduced diversity in their diets. The high prevalence of flatfish in their pellets indicates they are feeding on primarily benthic fish, and rarely pelagic fish.
Human interference
Mussel Farms
The Marlborough Sounds is home to over 900 mussel farms. The region produces 65,000 tonnes of green-lipped mussels annually. King shags are regularly seen in small numbers around mussel farms. In non-breeding seasons, higher numbers of adults are seen at mussel farms. This is because there is no need for one adult to stay at the nest to care for chicks. Mussel farms seem to have a neutral effect on king shags. There was worry that the space used for mussel farming would reduce foraging grounds for king shags, but the populations are not affected meaningfully by current aquaculture
Aquaculture (less commonly spelled aquiculture), also known as aquafarming, is the controlled cultivation ("farming") of aquatic organisms such as fish, crustaceans, mollusks, algae and other organisms of value such as aquatic plants (e.g. Nelu ...
. Colony proximity to the farms is a predictor of foraging within them. Both adults and juveniles have been seen roosting temporarily during the evening at mussel farms. It is thought that the structure of mussel farms, with their floating buoys, offer temporary spots to roost and preen before returning to the colony. Areas surrounding the farms also see king shag foraging activity during the day. There is no indication that king shags consume the mussels, rather than the farms attract fish they then prey on.
Disturbance
Fishing and travel through the Marlborough Sounds by boat are considered the largest forms of disturbance to king shags. When loud boats infringe on king shag territories, they will be abandoned. Most notably, the Sentinel Rock colony of king shags was once one of the largest, and now is abandoned. On average, studied individuals were disturbed once every 2 days. The highest proportion of disturbances occurred on Friday, Saturday, and Sunday. On these days, activity from mussel farms is greatly reduced, but recreational fishing
Fishing is the activity of trying to catch fish. Fish are often caught as wildlife from the natural environment (Freshwater ecosystem, freshwater or Marine ecosystem, marine), but may also be caught from Fish stocking, stocked Body of water, ...
is popular. Recreational fishing in areas around king shag colonies threatens to drive the birds away. This could reduce available nesting space, and could cause a population reduction if not managed.
References
External links
Image and Classification at Animal Diversity Web
{{Taxonbar, from=Q25626
New Zealand king shag
Endemic birds of New Zealand
Vulnerable fauna of Oceania
Marlborough Sounds
New Zealand king shag
New Zealand king shag