Seabirds, including cormorants, generally live in flocks. A bird living in a colony feels much more secure, is less likely to fall into the clutches of a predator, and has a greater chance of successfully raising its young. The cormorant is a black seabird belonging to the order Pelecaniformes and the genus Cormorantidae.
Cormorants are duck-like in size, with a body length of 5–100 cm and a wingspan of 80–160 cm. Females are generally smaller than males. The feather color changes as it matures: Juveniles have lighter, brown plumage, which becomes darker with age, acquiring a black color with a bluish or metallic tint.
All representatives of the cormorant genus have a long, thin beak, similar to a fish hook, bare areas of skin around the eyes and on the head, and a throat pouch.
Types
There are more than 30 subspecies of the cormorant genus in nature: freshwater and marine, sedentary and migratory.
- Small variegated;
- crested;
- big;
- Indian;
- red-faced;
- Berings;
- Antarctic blue-eyed;
- eared;
- Brandt;
- Biguansky;
- Bougainvillea;
- Cape;
- Persian;
- Magellan;
- reed;
- forelock;
- New Zealand;
- Steller's;
- white-breasted;
- Auckland and others.
The crested and white cormorants are considered to be among the rarest species.
White is born yet less common than white crowsThis subspecies is distinguished by its greyish or white plumage.
The crested one is quite rare. and is listed in the Red Data Book of Ukraine. In Russia, the nests of this species are also protected.
This subspecies is found on the Kola Peninsula (Russia), Africa, the Black and Mediterranean coasts, Ireland, England, and Norway. Three varieties of the Great Cormorant are distinguished based on bill color and proportions.
The birds are both sedentary and nomadic lifestyleThey spend most of their time at sea and rarely appear on land—only when they begin nesting.
Life in a pack and "marital unions"
Cormorants prefer to form large, even enormous colonies, which sometimes contain hundreds of thousands of birds, along with other marine animals and birds, such as fur seals and penguins.
It is believed that these Birds are monogamous, creating a union, they live with their "chosen one" ("chosen one") throughout their lives. They build nests from twigs and grass in bushes, rocks, trees, and even directly on flat surfaces.
In the spring (only when it's warm), females lay eggs (2-5). The male and female incubate them in turn, and both parents share the responsibility of feeding the chicks: while one sits in the nest with the "children," the other forages for food, and vice versa.
In hot weather both parents hunt only in the morning and eveningDuring the day, they sit in the nest, shielding their chicks from the scorching sun with their wings. To help the brood cope with the heat, the cormorants bring wet seaweed to the nest.
Newborn chicks are helpless and hairless, and their first plumage appears only after 30 to 80 days (depending on the variety). But even The grown chicks continue to live with their parents, who continue to feed them. They leave their parental home only after they have started their own family. The time to sexual maturity also depends on the species and ranges from 2 to 4 years.
Nutrition
Fish is a favorite food of these birds, and they can go fishing in large groups, inviting their pelican friends along. The group drives the fish to shallow water, where they then share the fish.
The basis of the diet is small or medium-sized fish: sardines, herring, anchovies, capelin. However, they are not averse to enjoy sea turtles, insects, and mollusksThese birds can stay underwater for about two minutes, diving to depths of up to 15 meters. Cormorants dive directly from the surface or leap from branches, creating no waves and making absolutely no noise. A cormorant can eat up to 500 grams of fish per day.
Freshwater cormorants, in addition to fish, also feed on frogs and crayfish.
Man and Cormorant
For many years, fishermen in Japan and China used members of this genus for fishing. Today, this tradition survives only as a form of entertainment for tourists: specially trained birds dive for fish at night, and the coastline is illuminated by lit torches. Besides being a beautiful and mesmerizing sight, the attraction is also beneficial: in a very short time, you can catch a whole basket of fish.
Groups of cormorants, either permanently inhabiting the coast or staying for the winter, create many problems for local residents. The reason is that The birds are very voracious and can eat up to 500 grams of fish per day., and a large population of these birds in a single body of water significantly reduces the fish stock. The guano-bird droppings of cormorants are used by humans as a valuable fertilizer.
Enemies
The cormorant's worst enemies are considered to be crows, which try to steal eggs from the nest, sometimes with the same purpose Seagulls and starlings are trying to get into the cormorant's "home"And hatched chicks risk becoming prey to raccoons, coyotes, and wild foxes.
Habitats
This bird species lives in both hot and cold climates. They inhabit river and lake shores, coastal areas, and some even settle in swamps. Thus, cormorants are found almost everywhere.
There are 6 species found in Russia, of which the most common is the great cormorantBesides this, the following subspecies are also found:
- small;
- red-faced;
- Berings;
- crested;
- Japanese.
The little cormorant and the great cormorant are listed in the Red Data Book of Russia. The great cormorant is found on five continents. These birds typically inhabit coastal areas, but can sometimes be found in the estuaries of lakes and rivers, and even more rarely in continental regions.
Interesting facts
In dangerous situations, birds swim underwater, keeping only their neck and head above the surface. Swallows flying low over the water can also become prey for cormorants.In dry and hot weather, parents bring water to their chicks directly in their beaks.
Although some consider cormorants to be stupid and gluttonous birds, these birds are actually beautiful and intelligent in their own way. Sensing danger, they instantly decide to hide. Moreover, cormorants are excellent divers and excellent family members.
