Flightless Cormorant

Flightless Cormorant

Galapagos cormorant

Kingdom
Phylum
Class
Subclass
Infraclass
Superorder
Order
SPECIES
Phalacrocorax harrisi
Population size
1,602
Life Span
13 yrs
WEIGHT
2.5-5 kg
LENGTH
89-100 cm

Cormorants are water birds, largish, with elongated bodies, short legs that are set back, large, webbed feet, and long necks with long, hooked bills used for catching fish underwater. They can be difficult to spot when on the water’s surface, as they keep their body low, sometimes only their head and neck showing. They are rather ungainly on land, walking slowly and methodically. When returning to land after feeding at sea, they stretch out their wings to dry. This cormorant is the only flightless one, and is the one variety of cormorant living on the Galápagos Islands. Males and females look similar, although males are usually much larger.

Distibution

This unique cormorant (also called the Galapagos cormorant) is endemic to Ecuador’s Galapagos Islands, where its range is very restricted, to just two volcanic islands: Isabela on the western and northern coasts, and on Fernandina, where it inhabits the rocky shores. It forages in the shallow waters around the coast, including bays and straits, rarely venturing more than 1 km from the breeding areas.

Geography

Continents
Countries

Climate zones

Habits and Lifestyle

The loss of flight in this species is thought to be due to a long evolutionary period on islands that are isolated and predator-free, and also because they forage within a very small range. Unlike penguins, which use their flipper-like wings to ‘fly’ through the water, the Flightless cormorant moves along by kicking with its strongly-built legs. Cormorants are aquatic predators; however, they do not have waterproof feathers. A characteristic behavior of cormorants when coming out of the water is to hold the wings open to dry the feathers, and Flightless cormorants do this too, and are often seen holding their little ragged wings out from their sides. These are sedentary birds, limited by their particular build. They form a strong attachment to their breeding grounds, remaining within one kilometer, even for feeding. These birds are usually silent except for during the breeding season, and the low growling sounds they make often relate to breeding or roosting behavior.

Diet and Nutrition

Flightless cormorants are carnivores (piscivores), they mainly eat fish, like eels and rockfish. Near the bottom of the sea it will forage for octopus and squid.

Mating Habits

MATING BEHAVIOR
REPRODUCTION SEASON
March-September
INCUBATION PERIOD
35 days
INDEPENDENT AGE
6 months
BABY NAME
shaglet, chick
BABY CARRYING
2-3 eggs

Flightless cormorants are a serially monogamous species, and pair-bonds last for one clutch only, sometimes two. Laying may take place at any time of the year but is usually between March and September. Two clutches may be produced at this time. Breeding colonies of about 12 pairs form. Courtship behavior starts in the sea, with the male and female swimming around each other, their necks bent in a snake-like position. Then they move onto land. Their bulky seaweed nest, positioned just above the high-water mark, has ‘gifts’ added to it, such as pieces of flotsam like rope and bottle caps, presented by the male to the female. 2-3 white eggs are laid and both parents take turns incubating them for 35 days. They will often exchange coarse grunts during the changeover, and the one returning to the nest offers a piece of seaweed to its mate to strengthen their pair bond. Usually 2 eggs hatch, but just one chick fledges. The newborn chicks are naked, but their blackish down grows very quickly. Fledging is after 2 months but a chick depends on its parents for about 4 more months and will reach maturity in its second year.

Population

Population threats

Not being able to fly and not dispersing means that this species is highly vulnerable to human disturbance and environmental disasters like oil pollution. It is also entirely fearless of humans, further increasing its susceptibility to disturbance. The potential introduction of cats or rats on Fernandina Island is a huge threat. Net fishing reduces the availability of this bird’s food, and often they are caught in them and die. El Niño and other natural disasters also kill many of them.

Population number

According to the IUCN Red List, the total number of Flightless cormorants is 1,602 mature individuals. There are 700 - 800 pairs in 100 small colonies living on the Galapagos Islands, according to the Quasar Expeditions resource. Currently this species is classified as Vulnerable (VU) on the IUCN Red List, but its numbers today remain stable.

Fun Facts for Kids

  • The feathers of Flightless cormorants are not waterproof.
  • Adult Flightless cormorants have an amazing turquoise eyes color. Young birds’ eye color is dull brown.
  • The wings of this species no longer work for flying, but it can swim and dive to catch prey better than cormorants which can fly.
  • There are two likely reasons that this species is the only Flightless cormorant: first, all the food it needs is within only about 100 meters from the shoreline and, second, these birds have no natural large predators on land.
  • The body feathers of the Flightless cormorant are much more luxurious than the feathers of the flying cormorants. They are thick, soft and dense, to protect them from the water and help keep them afloat. When air is trapped within these dense feathers, this helps them float, acting like a protective vest.

References

1. Flightless Cormorant Wikipedia article - https://en.wikipedia.org/wiki/Flightless_cormorant
2. Flightless Cormorant on The IUCN Red List site - http://www.iucnredlist.org/details/22696756/0

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