Bird O'clock

Discover the Fascinating Behavior and Ecology of Black-Faced Cormorants!

Black-faced Cormorant: A Master Diver of the Pacific OceanImagine a bird that can swim up to 50 meters deep and stay underwater for a minute while searching for food. This bird is the Black-faced Cormorant, a fascinating species of cormorant that inhabits the Pacific Ocean.

In this article, we will discuss how to identify Black-faced Cormorants, including their plumages and molts, and identify some of the similar species.

Identification

Field Identification

The Black-faced Cormorant is a large, dark seabird with a wingspan of up to one meter. Unlike other cormorants, this species has a white rump, a black face, and a small, yellow patch of skin on the neck.

Their distinctive features make it easy to identify them from a distance. You may see them perching on rocks or cliffs near the shore, or flying low over the water in search of prey.

Similar Species

There are a few similar species that require attention to detail to differentiate them from the Black-faced Cormorant:

1. Double-crested Cormorant: This species is similar in size and shape to the Black-faced Cormorant but has white patches on its face and around the neck.

2. Pelagic Cormorant: This species is smaller than the Black-faced Cormorant and has a blacker face with a white chinstrap.

3. Brandt’s Cormorant: This species is larger than the Black-faced Cormorant and has a conspicuous white flank patch.

Plumages

Like most birds, the Black-faced Cormorant goes through several molts during its lifetime. Molting is the process of losing and replacing feathers.

The plumages of adult Black-faced Cormorants can be divided into three categories:

1.

Breeding Plumage: During the breeding season, adult Black-faced Cormorants have black feathers on their heads, necks, wings, and tails.

They have a small, yellow patch of bare skin on the neck, and the eyes are surrounded by a blueish-white ring. 2.

Alternate Plumage: During non-breeding seasons, the adult Black-faced Cormorants have brownish-black plumage on their heads, necks, and upperparts. The eyes are surrounded by a grayish-white ring, and the feathers on their bellies are white.

3. Basic Plumage: The basic plumage of Black-faced Cormorants is similar to the alternate plumage but is more faded and less defined.

Molts

Black-faced Cormorants go through two primary molts each year, the prebasic and prealternate molts. The prebasic molt occurs in the late summer and early fall when adult Black-faced Cormorants replace their feathers just before migrating to their wintering grounds.

The prealternate molt occurs in the late winter and early spring, just before the breeding season, when birds replace their winter feathers with their breeding plumage. In conclusion, the Black-faced Cormorant is a fascinating bird species with unique characteristics that make them recognizable from a distance.

It is a master diver that can swim up to 50 meters deep and stay underwater for a minute while seeking prey. It’s important to know how to identify Black-faced Cormorants, including their plumages and molts, and also recognize other similar species that can be mistaken for them.

These large, dark seabirds are a remarkable and valued member of the Pacific Ocean ecosystem.

Systematics History and

Geographic Variation of Black-faced Cormorant

Black-faced Cormorants are fascinating seabirds that are native to the coasts of New Zealand, Tasmania, and the southern parts of Australia. They are members of the cormorant family (Phalacrocoracidae), which includes about 40 species of birds worldwide.

In this article, we will explore the systematics history of Black-faced Cormorants, their geographic variation, subspecies, and related species.

Systematics History

Phalacrocoracidae, or the cormorant family, is a part of Pelecaniformes, which also includes pelicans, egrets, herons, and ibises. The phylogeny of Pelecaniformes is still being researched, and the classification of its families has changed over time.

Initially, cormorants were classified as a monophyletic family, and the genus Phalacrocorax included all species. However, recent molecular studies have demonstrated that Phalacrocorax is not monophyletic.

Instead, most of the species have been placed in other genera, and some new genera have been proposed. The exact placement of Black-faced Cormorant within the family is not entirely resolved, but it is currently classified in the monotypic genus Phalacrocorax fuscescens.

Geographic Variation

The Black-faced Cormorant has a remarkably restricted geographic range, with breeding populations confined to the southern parts of Australia, Tasmania, and New Zealand. However, within this small range, there is considerable geographic variation.

Subspecies

There is no consensus on the subspecies within the Black-faced Cormorant, but some have proposed that the species is divided into four or five subspecies based on geography and morphology. 1.

Phalacrocorax fuscescens fuscescens: This subspecies is native to southern Australia, from Cape Leeuwin in the west to Cape Howe in the east.

2.

Phalacrocorax fuscescens richardsi: This subspecies is found in Tasmania and adjacent islands. It is slightly smaller than the nominate subspecies, with an overall smaller bill.

3. Phalacrocorax fuscescens albiventer: This subspecies is found in far southern Australia, from the Nullarbor Plain to the Eyre Peninsula.

It has a broader bill than other subspecies. 4.

Phalacrocorax fuscescens worcesteri: This subspecies is found on the Chatham Islands, east of New Zealand. It is the most distinct subspecies, with a paler face and different vocalizations.

Related Species

Black-faced Cormorants are closely related to other cormorant species found in the Australasian region. These include:

1.

Little Pied Cormorant (Microcarbo melanoleucos): This small cormorant is found throughout Australia, and its range overlaps with that of the Black-faced Cormorant. 2.

Australian Pied Cormorant (Phalacrocorax varius): This species is also closely related to Black-faced Cormorants and is found along the coasts and rivers of Australia. 3.

Imperial Cormorant (Phalacrocorax atriceps): This large cormorant is found in the southern parts of South America and is the closest living relative of the Black-faced Cormorant.

Historical Changes to Distribution

The distribution of the Black-faced Cormorant has changed significantly in recent times. The species’ numbers have declined in some areas, while it has expanded its range in others.

The reasons for these changes are complex but include a combination of natural factors and human impacts. Historically, Black-faced Cormorants were distributed throughout most of southern Australia, including the coasts of Western Australia and the Northern Territory.

However, by the mid 20th century, their range had shrunk considerably, and they were confined to the coasts of southern Australia, Tasmania, and New Zealand. This decline was likely due to the depletion of their prey, environmental changes, and hunting by humans.

In recent decades, Black-faced Cormorants have been expanding their range in some areas. For example, breeding populations have been documented along the coast of Western Australia, where the species was previously absent.

It is not entirely clear why they are expanding their range, but some suggest that changes in prey availability and climatic conditions may be factors.

In conclusion, Black-faced Cormorants are fascinating birds that are closely related to other cormorants in the Australasian region.

Their geographic range is restricted but has considerable variation within that range. The systematics history of cormorants is complex and has changed over time with the development of new research methods.

The distribution of Black-faced Cormorants has changed significantly over recent decades, and the reasons for these changes are complex but likely related to both natural and anthropogenic factors. The study of Black-faced Cormorant systematics and distribution provides valuable insights into the dynamics of seabird populations and their responses to environmental change.

Habitat and Movements of Black-faced Cormorant

The Black-faced Cormorant is a seabird that is found primarily in the southern parts of Australia, Tasmania, and New Zealand. They inhabit rocky coasts, offshore islands, and sometimes dive in estuaries, bays, and inlets.

In this article, we will explore the habitat and movements of the Black-faced Cormorant, including its migration patterns.

Habitat

Black-faced Cormorants prefer to nest on rocky ledges and cliffs overlooking the ocean. These rocky coasts provide an abundance of food, including fish, squid, and crustaceans.

They are also occasionally found in shallow, brackish lagoons, estuaries, and bays where they can find prey in shallower waters. These birds are generally found at low altitudes and do not venture far from the coast.

During breeding season, they may form colonies, often with other seabirds such as gulls or other species of cormorant. Black-faced Cormorants may also be seen roosting on offshore rocks, sometimes in large numbers, particularly outside of breeding season, when birds gather in communal roosts.

Movements and

Migration

Black-faced Cormorants are generally non-migratory, with most individuals living along the coasts of their breeding range year-round. However, some movements away from their breeding range can occur in response to food availability or other environmental factors.

During breeding season, Black-faced Cormorants may make locally movements to find suitable nesting sites and fishing grounds. These movements can vary, depending on the breeding colony’s location and the availability of food resources, but they generally do not travel more than a few kilometers from their breeding area.

Outside of the breeding season, birds can undertake longer-range movements. A few sightings of Black-faced Cormorants in southeastern Australia have been recorded, but these movements are relatively rare.

There is also some evidence that Black-faced Cormorants may undertake southward, coastal movements during the austral winter, most likely in search of food.

Migration

Some Black-faced Cormorants are known to disperse from their breeding grounds. These birds typically move only a few kilometers and often remain along the coast.

In some years, movement and dispersal may be more widespread, especially during declines in food abundance or in response to changes in weather patterns. Although Black-faced Cormorants are generally considered non-migratory, some individuals may occasionally be seen outside of their breeding range.

Birds have been sighted in areas along the coasts of southeastern Australia, and there is some evidence that Black-faced Cormorants may undertake more extensive coastal movements to find food and suitable habitat. It is not yet clear what factors drive these movements by Black-faced Cormorants, but it is likely that they are related to changes in the availability of prey, temperature, and ocean conditions.

In conclusion, the Black-faced Cormorant is a seabird species that prefers to inhabit rocky coasts and offshore islands. They are typically non-migratory but can make local movements throughout the year to find suitable nesting sites and fishing grounds.

Some birds may also undertake longer-range coastal movements, but the reasons for these movements are not yet fully understood. The study of Black-faced Cormorant habitat and movements provides valuable insights into the behavior and ecology of this fascinating seabird species.

Diet and Foraging Habits, and Sounds and Vocal Behavior of Black-faced Cormorant

The Black-faced Cormorant is a fascinating seabird species that inhabits the southern coasts of Australia, Tasmania, and New Zealand. They are members of the cormorant family, which includes birds that are adapted to foraging in marine environments.

In this article, we will explore the diet and foraging habits of the Black-faced Cormorant, as well as its sounds and vocal behavior.

Diet and Foraging Habits

Feeding

Black-faced Cormorants are expert divers and forage mostly by diving in the ocean. They have been recorded diving to depths of up to 50 meters, though most of their dives average around 10 to 20 meters.

Black-faced Cormorants are known to dive for periods of up to a minute, using their webbed feet to propel themselves through the water in search of prey. They typically hunt fish, squid, octopus, and crustaceans.

Diet

The diet of Black-faced Cormorants is likely to change between breeding and non-breeding seasons, depending on the availability of prey. During non-breeding seasons, their diet mainly consists of small fish, squid, and crustaceans.

In contrast, during the breeding season, the diet shifts to larger fish species, with fish species such as snapper, whiting, and leatherjacket being recorded in the diet. Black-faced Cormorants have a unique method of hunting that involves regurgitating food to entice prey to the surface.

They also swallow rocks and small stones, which help them in digestion by grinding the prey they consume.

Metabolism and Temperature Regulation

Black-faced Cormorants, like other seabirds, have a high metabolic rate that enables them to maintain their body temperature in cold marine environments. This high metabolic rate requires the birds to consume a large amount of food to fuel their metabolism.

The Black-faced Cormorant has adapted to this high-energy need by developing a gastrointestinal tract that is more efficient in absorption of nutrients and allowing for a higher-energy diet. The birds, however, also experience a balancing act between having a high metabolism and excessive energy expenditure.

They periodically rest on land or rocks to conserve energy and avoid exposing themselves excessively to oceanic winds and cold waters.

Sounds and Vocal Behavior

Vocalization

The Black-faced Cormorant is not as vocally active as other birds, but it does make a range of distinctive noises. The birds are sometimes heard making low-pitched grunting or moaning sounds.

They also make a variety of calls during courtship or when communicating with their young or other birds in the colony. During breeding season, males produce quiet, grunting vocalizations, especially when they interact with females.

Females, in turn, make a coarser, guttural call as a response to the males’ vocalizations. In addition to these vocalizations, Black-faced Cormorants also use non-vocal sounds, such as bill clattering, to communicate with each other.

In conclusion, Black-faced Cormorants are seabirds that are adapted to foraging in marine environments, mainly diving for their prey and consuming fish, squid, and crustaceans. They also possess uniquely designed gastrointestinal tracts that help in efficient nutrient absorption and a high metabolic rate needed to maintain body temperature in their cold marine environments.

The birds have a vocal repertoire that is not very diverse but includes distinctive noises such as grunting vocalizations during courtship or communication, and non-vocal sounds such as bill clattering. Studying the diet, foraging habits, and vocal behavior of Black-faced Cormorants provides insights into the ecology of these fascinating seabirds.

Behavior,

Breeding, and Demography and Populations of the Black-faced Cormorant

The Black-faced Cormorant is a seabird species that is distributed along the southern coasts of Australia, Tasmania, and New Zealand. These birds display a range of fascinating behaviors, including their locomotion, self-maintenance, agonistic behavior, sexual behavior, and breeding behavior.

In this article, we will delve into the different behaviors exhibited by this species and examine how demography and populations are affected by these behaviors.

Behavior

Locomotion

Black-faced Cormorants are master divers with strong, webbed feet that enable them to swim quickly and efficiently underwater. They propel themselves by vigorously flapping their wings and change direction by using their legs as rudders.

On land or rocks, they move by walking awkwardly or sliding on their bellies.

Self Maintenance

Black-faced Cormorants are highly social birds and spend a considerable amount of time grooming their feathers, a behavior that helps maintain their insulating properties, waterproof qualities, and make them more aerodynamic for flying. They use their bills to preen and arrange their feathers to remove dirt, oil, and other contaminants from their plumage.

Agonistic Behavior

Black-faced Cormorants are territorial birds, especially during the breeding season, and they defend their nesting area aggressively to prevent other birds from encroaching. They also engage in aggressive interactions with other cormorants or other birds who may come too close to their hunting grounds or nesting area.

Sexual Behavior

During the breeding season, Black-faced Cormorants engage in elaborate courtship behavior. Males often perform a head-tossing motion where they present themselves to females with fully expanded wings and head held forward.

They also produce quiet, grunting vocalizations, and females respond with guttural calls. The pair then perform a series of synchronized, underwater twists and turns.

After mating, pair bond is maintained for the following breeding seasons.

Breeding

Black-faced Cormorants breed during the austral spring and summer. During the breeding season, they form breeding colonies on rocky ledges overlooking

Popular Posts