Imagine if every spring your throat turned blue, and you had to build a new house for your family. This is what Brandt’s cormorants do every year.
Brandt’s cormorant (Phalacrocorax penicillatus) is one of 40 species of large seabirds from the family Phalacrocoracidae. The average Brandt’s cormorant stands 79 cm tall, about the size of a typical human toddler, with a wingspan twice as wide as the bird is tall. Juveniles exhibit brown and grey plumage and brown eyes. Adults have black feathers and blue-green irises. In breeding season, a pouch beneath the throat called a gular pouch becomes distinctly blue, along with blue and green tints amid the black plumage. The blue gular pouch distinguishes the Brandt’s cormorant from pelagic cormorants (Phalacrocorax pelagicus), which are of similar plumage but slightly smaller in size.
Habitat and Distribution
The Brandt’s cormorant is closely tied to the California Current, which delivers cold water down the Pacific Coast from Alaska to the Baja Peninsula. A convergence of northern winds generates an upwelling of nutrients along the coast between central Oregon and southern California along the California Current. This upwelling lures smaller fish, such as anchovies and sardines, that cormorants prefer to eat.
Nesting colonies develop on rocky offshore islets. Brandt’s cormorants feed away from nesting areas, floating in deeper coastal waters with spawning fish populations. Brandt’s cormorants move around frequently to find the best places to fish.
Behavior and Feeding
Brandt’s cormorants appear clumsy waddling around on land but are tremendous divers. Fishing vessels have caught them in nets at depths between 55 and 70 m deep. In flight, the birds avoid crossing land, remaining low over the water along shorelines.
Unlike pelagic and double-crested (Phalacrocorax auritus) cormorants who feed closer to shore or in bays, Brandt’s cormorants prefer deep water to hunt. The birds form large rafts, which are floating groups of birds, over open water, then dive deep in flocks, circling fish into tighter schools for more convenient feeding.
Reproduction and Life Cycle
Reproduction begins with the arrival of males to build nests in early spring. They often build in the same location as the previous season and may fight with another bird for the space. From half-constructed nests, males spread their wings, point their beaks to the sky, and tilt their heads back to show off their bright blue gular pouch. Females arrive and choose males based on their display of plumage rather than nest-building skills, as both sexes share in the complex labor of nest construction once the female has arrived.
About three eggs result from these encounters. Older birds show greater reproductive success. They arrive earlier than their younger counterparts, pick partners fast, and are more likely to produce more than one clutch of eggs if predators steal the first clutch. A study of Brandt’s cormorant colonies in the Farallon Islands, California, estimated that 70% of males return to the same nest, versus just 32% of females. Individuals often couple with the same mate over several years.
On expeditions for the Smithsonian Institution in the early twentieth century, ornithologist Arthur Cleveland Bent described a Brandt’s cormorant chick as “blind and naked, an ugly object with greasy black skin.” Soon a soft down coat appears before the bird is half grown. Nestlings are fully feathered by the time they fledge at 5 to 6 weeks old.
Young birds leave the nest and may remain away a year or more before returning to breed. Females breed at two to three years of age, a year earlier than males. The oldest Brandt’s cormorants live up to 18 years.
- Brandt’s cormorant is named for Russian ornithologist J.F. Brandt, who first described the species in 1838. A specimen made its way to Brandt’s desk at the Zoological Museum of St. Petersburg after Russian expeditions along the Pacific Coast in the early nineteenth century.
- Pioneer ornithologist Arthur Cleveland Bent published some of the earliest observations of the Brandt’s cormorant. He observed gulls, much smaller birds, stealing eggs from Brandt’s cormorant’s nests because the gulls could startle “the stupid birds” off their nests with loud noises.
Where to See
Within the Klamath Network parks, a breeding colony of Brandt’s cormorants can be seen with a set of binoculars from shore along the Yurok Loop Trail in Redwood National and State Parks. Boaters will enjoy the best views on rocky islets offshore.