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10 Fascinating Facts About the Campbell Islands Shag

The Campbell Islands shag, Leucocarbo campbelli, is a species of bird that is found in the Southern Ocean, specifically on the Campbell Islands in New Zealand. This bird is a member of the cormorant family and is characterized by its black and white plumage.

In this article, we will explore the identification, plumages and molts of the Campbell Islands shag in detail, providing a comprehensive guide for amateur birdwatchers and enthusiasts alike.

Identification

Field Identification

The Campbell Islands shag is a medium-sized bird that is approximately 60-70cm in length and weighs around 1.5kg. It has a wingspan of around 1m and is characterized by its black and white plumage.

The upperparts of the bird are black and the underparts are white. The face, throat, and neck of the bird are black, and the eyes are a bright blue color.

The bill is long and hooked, and the legs and feet are black.

Similar Species

The Campbell Islands shag is often confused with the Stewart Island shag, with which it shares a similar appearance. However, the distinguishing feature of the Campbell Islands shag is its bill, which is longer and more hooked than that of the Stewart Island shag.

Furthermore, the Campbell Islands shag has a blue eye-ring, whereas the Stewart Island shag has a yellowish eye-ring.

Plumages

The Campbell Islands shag has two distinct plumages: the breeding plumage and the non-breeding plumage. The breeding plumage is characterized by a distinct crest of feathers on the forehead, throat, and neck, which is absent in the non-breeding plumage.

Molts

The Campbell Islands shag goes through an annual molt, which occurs after the breeding season. During the molt, the feathers on the bird’s body are shed, and new feathers grow in their place.

The molt can take several months to complete, and during this time, the bird is unable to fly, as its wings are not fully developed.

Conclusion

In conclusion, the Campbell Islands shag is an interesting species of bird that is easily identifiable by its black and white plumage, long hooked bill, and blue eye-ring. Its two distinct plumages and annual molt provide further insights into the lifecycle and behavior of this remarkable bird.

Whether you are a seasoned birder or a first-time observer, the Campbell Islands shag is a fascinating species that is sure to captivate your attention.

Systematics History

The Campbell Islands shag, Leucocarbo campbelli, was originally described by ornithologist John Edward Gray in 1846, who included it in the genus Phalacrocorax. Later, based on morphological data and DNA evidence, the genus was split, and the Campbell Islands shag was placed in the genus Leucocarbo.

Geographic Variation

The Campbell Islands shag has a restricted range and is found only on the Campbell Islands, which are located in the Southern Ocean. However, populations on the northern part of the island have different plumage characteristics from the southern populations.

Subspecies

There are no currently recognized subspecies of the Campbell Islands shag. However, the populations on the northern part of the island have been proposed to be a distinct subspecies based on their plumage characteristics.

Related Species

The Campbell Islands shag is part of the cormorant family and is closely related to other shag species, such as the Stewart Island shag and the spotted shag. DNA analysis has shown that these three species are sister taxa and are more closely related to each other than to any other species in the family.

Historical Changes to Distribution

The Campbell Islands shag has a restricted distribution and is only found on the Campbell Islands. However, historical evidence suggests that the bird may have had a wider distribution in the past.

Early explorers reported seeing shags on mainland New Zealand, but it is unclear whether these were Campbell Islands shags or another species of shag.

The arrival of humans on the Campbell Islands in the 1800s had a significant impact on the Campbell Islands shag population.

The introduction of rats, cats, pigs, and other invasive species led to a decline in the bird’s numbers, and by the early 1900s, the species was thought to be extinct. However, in the 1940s, a small population of Campbell Islands shags was discovered on Dent Island, a small islet off the coast of the main island.

This population was found to be isolated from the mainland population and was thought to be a remnant of an ancient population that had survived the impact of human settlement. Since the discovery of the Dent Island population, conservation efforts have been made to protect and conserve the species.

Predator control programs have been implemented, and the bird’s population has gradually increased. Today, the Campbell Islands shag is still an endangered species, but its population is stable, and conservation efforts continue to ensure its survival.

Conclusion

In conclusion, the Campbell Islands shag is a unique and fascinating bird with a restricted distribution on the Campbell Islands. The northern and southern populations have distinct plumage characteristics, and the bird is closely related to other shag species in the cormorant family.

Human impact and the introduction of invasive species led to a decline in the bird’s numbers, but conservation efforts have helped to protect and conserve the species. The story of the Campbell Islands shag is a reminder of the importance of conservation efforts in protecting and preserving the natural world.

Habitat

The Campbell Islands shag is a marine bird that is found on the rocky shores of the Campbell Islands. The bird is generally found in areas that are not exposed to the open ocean, such as bays and inlets.

The vegetation on the islands is limited and consists mainly of tussock grass and low shrubs, which the bird uses for nesting.

Movements and Migration

The Campbell Islands shag is a non-migratory bird and is believed to remain on the Campbell Islands throughout the year. However, the bird is known to make seasonal movements within the islands in response to changes in food availability.

During the breeding season, which occurs from October to January, the Campbell Islands shag nests on the rocky cliffs of the island. The bird builds its nest from sticks, grass, and seaweed, and lays two to three eggs.

Both parents participate in incubating the eggs and raising the chicks. The chicks hatch after around 30 days and are fed regurgitated fish by their parents.

After the breeding season, the Campbell Islands shag undergoes a molting period, during which it is unable to fly. During this time, the bird remains on the island and is vulnerable to predation.

However, molting periods do not occur in all individuals at the same time, and some birds may delay their molt until food is abundant. Outside of the breeding season and molting period, the Campbell Islands shag spends much of its time foraging in the waters around the islands.

The bird is adapted for diving and can dive up to 50 meters below the water’s surface to catch fish and other prey. The diet of the Campbell Islands shag consists mainly of fish, but it also feeds on squid, octopus, and other marine invertebrates.

Conclusion

In conclusion, the Campbell Islands shag is a non-migratory bird that is adapted to life on the rocky shores of the Campbell Islands. The bird’s movements within the islands are driven by changes in food availability, and the breeding season is a time of intense activity for the species.

Despite the bird’s vulnerability to predation during the molting period, conservation efforts have helped to protect and conserve the species. The Campbell Islands shag is a remarkable species that provides important insights into the behavior and ecology of marine birds in the Southern Ocean.

Diet and Foraging

Feeding

The Campbell Islands shag is a marine bird that is adapted to life in the water. It is a skilled swimmer and diver, using its wings to propel itself through the water.

The bird is able to dive to considerable depths – up to 50 meters – to catch fish and other prey.

Diet

The diet of the Campbell Islands shag is primarily fish, with the bird feeding on a variety of species. The most common fish species consumed by the bird include red cod, blue cod, and greenbone.

The bird also feeds on squid and octopus, as well as a range of other marine invertebrates.

Metabolism and Temperature Regulation

The Campbell Islands shag has a high metabolic rate compared to other birds, which is thought to be an adaptation to its diving behavior. When the bird is submerged in water, its metabolic rate increases to provide the energy needed to swim and dive.

This high metabolic rate also helps the bird to maintain its body temperature in cold water. To reduce heat loss, the Campbell Islands shag has a thick layer of feathers that insulates its body.

The layer of feathers traps a layer of air next to the bird’s skin, which helps to keep it warm. The bird also has an oil gland at the base of its tail, which produces oil that the bird spreads over its feathers to make them more waterproof.

Sounds and Vocal Behavior

Vocalization

The Campbell Islands shag is generally a silent bird, but it does make a variety of sounds for communication during the breeding season. The most common sound made by the bird is a croaking call, which is used for territorial defense and communication between mating pairs.

The bird also makes a variety of other calls during the breeding season, including a series of short, harsh squawks and a long, gutteral growl. These calls are used to signal aggression, assert dominance, and attract mates.

In addition to vocalizations, the Campbell Islands shag also uses body language and visual signals to communicate. During displays of aggression, the bird will flare its feathers, stretch its neck, and point its bill towards its opponent.

The bird also uses visual displays, such as head-raising and bill-nipping, to signal its intentions to other birds.

Conclusion

In conclusion, the Campbell Islands shag is a marine bird that is well-adapted to life in the water. Its diving ability and high metabolic rate make it an excellent hunter, and the bird feeds primarily on fish.

The bird’s thick layer of feathers and oil gland help it to regulate its body temperature and stay warm in cold water. Although generally a silent bird, the Campbell Islands shag can make a variety of vocalizations during the breeding season for communication and signaling.

The bird’s unique adaptation to its environment makes it a fascinating species to study for birdwatchers and ornithologists alike.

Behavior

Locomotion

The Campbell Islands shag is a skilled swimmer and diver, using its wings to propel itself through the water. When on land, the bird walks on its webbed feet, but it is not as agile as other shorebirds due to its large size and body shape.

Self Maintenance

The Campbell Islands shag regularly preens its feathers to keep them clean and waterproof. The bird also has an oil gland at the base of its tail, which produces oil that the bird spreads over its feathers to make them more waterproof.

Agonistic Behavior

The Campbell Islands shag is a territorial bird and will defend its nest site aggressively against intruders. Displays of aggression include head-lowering, bill-nipping, and feather-fluffing.

The bird is also known to make a loud, guttural growling sound to signal its aggression.

Sexual Behavior

During the breeding season, males will perform displays to attract mates. These displays involve stretching the neck upwards, opening the mouth, and calling loudly.

Males also defend territories and will engage in aggressive displays to keep rivals away from potential mates.

Breeding

The breeding season for the Campbell Islands shag occurs from October to January. During this time, the bird nests on the rocky cliffs of the Campbell Islands.

The nest is constructed from sticks, grass, and seaweed, and the female will typically lay two to three eggs. Both parents participate in incubating the eggs and raising the chicks, with chicks hatching after around 30 days.

Demography and Populations

The Campbell Islands shag has a restricted distribution and small population size, making it vulnerable to declines and extinction. However, since the discovery of the Dent Island population in the 1940s, conservation efforts have been implemented to protect and conserve the species.

Predator control programs have been established to reduce the impact of invasive species, such as rats and cats, on the bird’s population. In addition, habitat restoration programs have been established to restore areas of the island that have been impacted by human activity.

The Campbell Islands shag is currently classified as an endangered species by the IUCN. However, the bird’s population has shown signs of recovery in recent years, with the population estimated to be around 1,500 individuals.

Continued conservation efforts will be needed to ensure the long-term survival of this unique and fascinating species.

Conclusion

In conclusion, the Campbell Islands shag is a fascinating species with unique behaviors and adaptations that make it well-adapted to life in the Southern Ocean. The bird’s breeding season, territorial behavior, and sexual displays provide a fascinating insight into the bird’s behavior, while conservation efforts have ensured the survival of this unique species.

Despite its restricted distribution and small population size, the Campbell Islands shag continues to be a resilient and charismatic bird with much still to learn about its behavior and ecology. In conclusion, the Campbell Islands shag is a remarkable bird that has adapted to life in the harsh environment of the Southern Ocean.

Its unique characteristics, such as its black and white plumage, long hooked bill, and diving ability, make it a fascinating species to observe and study. The bird’s restricted distribution and small population size make it an endangered species that requires continued conservation efforts to ensure its survival.

The Campbell Islands shag serves as a reminder of the importance of protecting and conserving our natural world and the remarkable diversity of life it supports. By studying and protecting species like the Campbell Islands shag, we can continue to learn more about our planet and the vital ecosystems that sustain us all.

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