The Cormorants of Australia: Masters of Air, Water, and Land
Australia is home to five distinct species of cormorants, remarkable waterbirds that have captivated observers with their unique adaptations and behaviors. These skilled fish-hunters are among the few bird species capable of excelling in three realms: flying strongly over long distances, swimming with lengthy underwater dives, and walking on land. While there are approximately 30 to 40 species of cormorants worldwide, Australia's five endemic varieties showcase the diversity and adaptability of this ancient family of birds.
The Five Australian Species
Great Cormorant (Phalacrocorax carbo) The Great Cormorant holds the distinction of being the largest cormorant in Australia and ranks among the largest in the world. This impressive bird is almost entirely black in plumage, distinguished by a white and yellow chin and small white patches on each thigh during breeding season. The bill is grey, while the legs and feet are black. Young birds display a more dusky-brown coloration compared to adults.
Despite preferring extensive areas of permanent freshwater, the Great Cormorant adapts readily to coastal inlets and estuaries. It is probably the most widespread member of the cormorant family globally, with populations extending across North America, Europe, Africa, China, India, Southeast Asia, New Zealand, Papua New Guinea, and throughout most of Australia, though it is more numerous in the southeast and southwest regions.
Australian Pied Cormorant (Phalacrocorax varius) The Pied Cormorant is a large bird standing between 65 to 85 centimeters tall with a wingspan of 110 to 130 centimeters. Males typically weigh around 2.2 kilograms, while females average 1.7 kilograms. This species is predominantly black on its back and upper wing surfaces, with striking white underparts. A distinctive yellow-orange patch sits between the bill and eye on each side of the head, which likely inspired some of its historical common names.
The Pied Cormorant possesses large webbed feet for pursuing fish underwater while steering with half-opened wings. Its large hooked bill, green eyes with blue eye rings, and special nictitating membranes for underwater eye protection make it a formidable underwater predator. Although typically found in marine habitats, either solitary, in pairs, or in vast flocks numbering in the hundreds or thousands, it is also attracted to inland waters including lakes, deep wetlands, and rivers.
Little Pied Cormorant (Microcarbo melanoleucos) Standing at around 50 centimeters, the Little Pied Cormorant is the smallest of the Australian cormorants and one of the most common waterbirds in Southeast Australia. It is easily recognizable, being entirely black above and white below. The face is dusky, and in adult birds, the white underside extends above the eye.
Despite its abundance, the Little Pied Cormorant is primarily a solitary bird, rarely seen in flocks. It will fish, feed, and fly independently, often perching happily with wings spread on wharfs, sea walls, and beaches. This species occurs on water bodies of almost any size throughout Australia.
Little Black Cormorant (Phalacrocorax sulcirostris) The Little Black Cormorant is a small bird, measuring about 60 centimeters high, with a slim build and, as its name suggests, totally black plumage featuring a greenish sheen on the back. It has a slender grey hooked bill. During breeding season, adults develop fine white flecks on the head and neck, and the green tinge becomes more bronze.
This species congregates in larger flocks than other cormorants and flies in distinctive V-shaped formations. Foraging flocks may number in the hundreds or possibly thousands, often feeding cooperatively. They employ sophisticated hunting strategies, surrounding schools of fish in open water and forming lines across marine inlets to catch fish washed out on ebbing tides. The Little Black Cormorant is found throughout Australia, including Tasmania, as well as from Borneo and Java to Papua New Guinea, Vanuatu, New Caledonia, Solomon Islands, Palau, and New Zealand.
Black-faced Cormorant (Phalacrocorax fuscescens) The Black-faced Cormorant is Australia's only fully marine cormorant, often called a "shag" in traditional nomenclature. This large pied species measures between 60 to 75 centimeters and features a distinctive naked black face. The upper parts are black while the underparts are white, with a black mark on each thigh. The bill is dark grey, eyes are blue-green, and legs and feet are black. It can be distinguished from the similarly sized Pied Cormorant by its black (rather than yellow-orange) facial skin and darker grey bill.
Physical Adaptations and Hunting Behavior
All Australian cormorants share several remarkable physical adaptations that make them exceptional aquatic hunters. Their large, fully webbed feet serve as powerful propellers underwater, allowing them to pursue prey with remarkable agility. They possess special nictitating membranes that cover and protect their eyes during dives, enabling excellent underwater vision even in murky conditions.
Cormorants are renowned for their diving prowess. Typical dive times average around 40 seconds, with recovery periods of 10 to 15 seconds between dives, though this varies depending on depth and hunting success. The Great Cormorant can dive for up to one minute, swimming and pursuing prey using its feet rather than wings for propulsion.
Their diet consists primarily of fish, particularly benthic species measuring 6 to 15 centimeters in length from waters less than 10 meters deep. This is supplemented by crustaceans such as prawns and shrimp, mollusks, cephalopods, aquatic insects, and occasionally frogs and sand worms. King George Whiting juveniles are among the known prey species.
The Wing-Spreading Phenomenon
One of the most iconic sights associated with cormorants is their distinctive posture of perching with wings outstretched after fishing. This behavior has generated numerous theories over the years, including suggestions that it aids thermoregulation, digestion, balance, or signals the presence of fish. However, detailed studies of the Great Cormorant have conclusively determined that this behavior serves to dry the plumage.
Cormorants have preen gland secretions used to maintain their feathers, but these provide inadequate waterproofing compared to many other waterbirds. This relative lack of waterproofing may actually be advantageous, as it reduces buoyancy and allows cormorants to spend longer periods underwater while hunting. However, it necessitates the regular drying of feathers after fishing expeditions.
Social Behavior and Breeding
Cormorants display fascinating social behaviors that vary by species. The Great Cormorant is highly sociable, forming colonies of about 2,000 birds during breeding season, with colonies of up to 20,000 birds having been reported. The Little Black Cormorant also forms large congregations, not just for breeding but regularly throughout the year, while the Little Pied Cormorant tends toward solitary behavior.
Breeding can occur at various times depending on food supply, with the Great Cormorant typically breeding between August and January. Both sexes collaborate in building nests, which are large stick structures placed either in low trees or on the ground. Both parents share incubation duties and care for the young.
Banding studies have revealed that Pied Cormorants do not travel far from their colonies, typically remaining within 20 kilometers. Their flight is generally at low altitude, as they possess weaker flight capabilities compared to other species in their family. When traveling in flocks, they often form V-shaped formations or fly in long lines.
Habitat and Distribution
Australian cormorants are coastal rather than oceanic birds, having successfully colonized the continent's estuaries and inland waters. They demonstrate remarkable adaptability to various aquatic environments, from freshwater lakes and rivers to brackish wetlands and marine coastal areas. The birds appear unaffected by variable salinity, turbidity, and shoreline vegetation types, provided suitable perches are available.
The Great Cormorant occurs throughout most of Australia but is more numerous in the southeast and southwest. The Pied Cormorant can be found in all states except Tasmania, while the Little Pied and Little Black Cormorants are distributed throughout Australia, including Tasmania. The Black-faced Cormorant, being strictly marine, has a more limited coastal distribution.
Conservation Status and Threats
The conservation status of Australian cormorants varies by species and region. Most species are considered secure at the federal level, though some face localized threats. The Pied Cormorant is listed as near threatened in Victoria. These birds face several human-related challenges:
Fishing Industry Interactions: Cormorants have been calculated to be at high to moderate risk from fishing activities, particularly from set and inshore drift nets. Birds in colonies are often observed entangled in recreational fishing line with hooks embedded in their bodies. Historically, cormorants were viewed as competition for commercial fishing operations and were sometimes shot, though this practice has largely ceased.
Habitat Degradation: While the deep open waters and estuaries favored by species like the Little Black Cormorant have been less affected by drainage than some other wetland habitats, breeding areas face threats from increased salinity, grazing, land clearing, and more frequent burning regimes.
Human Disturbance: As coastal and inland waterways become increasingly developed, cormorants must adapt to greater human presence, though many species, particularly the Pied Cormorant, show remarkable tolerance of human activity.
Cultural Significance
Cormorants hold special significance in Indigenous Australian culture. The Noongar Aboriginal people of southwestern Western Australia believe that the Pied Cormorant, known as "medi," is responsible for transporting the souls of deceased persons across and beneath the Western sea to their final resting place, called Kurannup. The term "medi" can be translated as "agent" or "medium," possibly referring to the bird's role as an intermediary between the living world and the afterlife. According to Noongar belief, spirits of the deceased rest temporarily on the moojar (Western Australian Christmas tree) before being carried by easterly winds or flowing waters to the sea, where the spirit joins with the medi for its final journey.
Observing Cormorants
For birdwatchers and nature enthusiasts, cormorants provide excellent opportunities for observation. Their tendency to roost in conspicuous locations on rocks, logs, jetties, and trees, combined with their characteristic wing-drying posture, makes them easy to spot. Early morning is an ideal time to observe their cooperative feeding behavior, as flocks marshal themselves at favorable locations and work their way along waterways in coordinated lines, driving schools of fish before them.
The diversity of Australian cormorant species means that observers can encounter different species depending on their location and habitat preferences. Coastal areas may reveal the exclusively marine Black-faced Cormorant, while inland freshwater bodies might host the Great or Little Pied varieties. The Little Black Cormorant's impressive flocking behavior and V-formation flights provide spectacular viewing opportunities.
Conclusion
Australia's five cormorant species represent a remarkable example of evolutionary adaptation and ecological success. Their mastery of multiple environments—air, water, and land—combined with sophisticated hunting strategies and complex social behaviors, makes them among the most fascinating waterbirds on the continent. From the majestic Great Cormorant to the diminutive Little Pied, each species fills a unique ecological niche in Australia's diverse aquatic ecosystems.
Despite facing various human-related threats, most Australian cormorant populations remain robust, testament to their adaptability and resilience. As both important components of aquatic food webs and subjects of cultural significance, these birds deserve our attention, respect, and conservation efforts. Whether observed solitary on a coastal rock, diving in coordinated flocks, or perched with wings spread in the morning sun, cormorants continue to captivate and inspire those fortunate enough to witness their remarkable behaviors.
