Cormorant bird’s other name is shag. These black underwater swimmers have been tamed for fishing. Cormorants dive for and feed mainly on fish of little value to Humans. Cormorant is a beautiful bird with an almost primitive appearance. Its long neck giving it a reptilian look. This Bird is often seen in a pose holding its wings out to dry. This bird is a supreme fisher, and this ability may be used in the Far East to man’s advantage or considered as competition in several other countries where these cormorants are persecuted.
Cormorants inhabit seacoasts, lakes, and some rivers. The nest may be made of seaweed and guano on a cliff or of sticks in a bush or tree. The two to four chalky eggs, pale blue when fresh, hatch in three to five weeks, and the young mature in the third year.
Cormorants and shags are medium-to-large seabirds. They range in size from the pygmy cormorant (Microcarbo pygmaeus), at as little as 45 cm (18 in) and 340 g (12 oz), to the flightless cormorant (Nannopterum harrisi), at a maximum size 100 cm (39 in) and 5 kg.
Cormorant are very Intelligent Birds
in China, hatchlings are taken from nests and hand-raised in baskets with hot-water bottles, and sold and traded for substantial sums. Ancient effigies have been found among the Incas of South America, and cormorants even fished for King James I of England the year 1610 in a specially constructed lake in Westminster. Cormorants that have colonized almost every part of the world — including the Hubbard Glacier of Alaska, where I recently photographed one sitting on a floating “growler.”
The key to their adaptable nature might be their intelligence — as evidenced by their ability to accurately count beyond the number seven. Chinese cormorants on the Li River are allowed to keep every eighth fish they catch. Otherwise they “stubbornly refuse to move again until their neck ring is loosened. They ignore an order to dive and even resist a rough push or a knock, sitting glum and motionless on their perches.”
Cormorant Follow others to catch their prey
A reddit u/SeeThroughCanoe recently posted an OC (original content) video of Cormorant following a large stingray to catch fish scared out of their hiding place in the seagrass by the passing ray [Here is the link to that post]. In comments he explained that this behavior of Cormorant has been observed before where Cormorant follows kayak to catch fish [Link to that video].
Reddit user u/SeeThroughCanoe said that there isn’t any information about this feeding behavior. To my knowledge it hasn’t been studied but I have seen it a few times. Cormorants also follow kayaks and other small boats to catch fish startled from their hiding places by the passing shadows of the boats. Although I’ve seen this a little bit in other parts of Florida, it seems like St Petersburg / Tampa area is where they do this the most frequently.
Cormorants almost went extinct along with the Bald Eagle
Many people think Cormorants are an invasive species. This is because they almost went extinct along with the Bald Eagle due to the use of the pesticide DDT in the middle of the last century. When DDT was banned in 1972 the Cormorant & Bald Eagle populations made a dramatic comeback.
In St Petersburg, Florida the cormorants often follow kayaks and paddleboards in shallow water to catch the fish that are startled out of their hiding places by the shadows of kayaks passing over them.
Edit addition = In general, fisherman hate Cormorants. Like many other animals such as dolphins, they blame them for a lack of fish. Numerous studies have been done that show that Cormorants are not the reason for declining fish populations in various parts of the country, but that doesn’t keep people from blaming the Cormorants.
Cormorants also nest in colonies, and their feces often kills the trees and vegetation after a few years. However, there are a LOT of bird species that nest in colonies and have adverse effects on the vegetation. It’s all part of the cycle of life though. And it’s worth noting that it pales in comparison to the damage that humans do to their environment.
Some Facts about Cormorants
Cormorants are expert divers, dive up to 4 minutes looking for food. Some types of Cormorant diving as deep as 45 meters (148 feet). They speed along underwater via their webbed feet, using their wings as rudders.
Some cormorant species are migratory, whereas others are sedentary.
All are fish-eaters, dining on small eels, fish, and even water snakes. They dive from the surface, though many species make a characteristic half-jump as they dive, presumably to give themselves a more streamlined entry into the water.
They have short wings for a flying bird due to their need to swim. Because of this they have the highest flight cost of any flying bird.
They are considered seasonally monogamous. The male chooses the nest site and then attracts a female. Nests can be on the ground, on rocks or reefs with no vegetation or atop trees.
Cormorants seem to be a very ancient group, with similar ancestors reaching back to the time of the dinosaurs. In fact, the earliest known modern bird, Gansus yumenensis, had essentially the same structure.
Humans have used cormorants’ fishing skills in various places in the world. Archaeological evidence suggests that cormorant fishing was practiced in Ancient Egypt, Peru, Korea and India, but the strongest tradition has remained in China and Japan, where it reached commercial-scale level in some areas.