Why are places of accumulation of birds called bird colonies. Bird markets. Why do birds get together

Those who have ever traveled by boat have probably noticed that when approaching the land, gulls and other sea birds appear in the sky. In the open sea, they are also found, but this is a rather rare occurrence.

What are they doing here?

First of all, seabirds owe their existence to the ocean that feeds them. Well, finding food is always easier near the shore. It's easy to explain. Krill, crustaceans, shrimp, clams, seaweed are all coastal marine life that fish feed on. Well, the fish serves as food for seabirds, which are skilled fishermen. They can hover over water for hours, looking for prey. If you carefully observe the same seagull, you can see how it falls into the water like a stone, dives, and in a moment appears on the surface with a fish in its beak. But if seabirds can fish all alone, then for the reproduction of offspring they create entire colonies on the shore, consisting of several thousand individuals. This noisy bird market settles down in the most suitable places for nesting.

Why do birds get together?

There are several reasons for this. One of them is the most effective protection against predators that cannot quietly penetrate the bird kingdom. Yes, and it is much easier to defend against them together. The second reason is related to the choice of nesting site. It should be not only convenient and safe, but also allow the birds to find food as quickly as possible. There are not so many such places in the coastal zone of the same Sea of ​​\u200b\u200bOkhotsk. That is why we are witnessing huge bird concentrations in rather small areas.

Guillemots, puffins, gulls, burgomasters occupy eaves and ledges of coastal rocks, build nests and incubate chicks. Periodically between them there are fights because of the territory. There are a lot of birds. At the slightest danger, they rise into the sky in a cloud, covering the sun with themselves. The bird market is always very noisy. The hubbub here does not subside for a minute.

A large number of bird colonies are located along the coast of the Sea of ​​Okhotsk. Near Cape Vostochny there is a group of rocky islands with the interesting name "Three Brothers". They are only a kilometer from the coast. The islands are three separate rocks, which at low tide are connected to each other by a narrow piece of land. This is an ideal place for nesting seabirds. It was chosen by puffins and gulls, which created a huge bird colony here.

Another bird colony is located in the Shelikhov Bay area, namely, on the five Yamsky Islands of the Pacific Ocean. These are small rocky formations, at the foot of which there are beautiful pebble beaches. During high tides, they are inaccessible, as they are flooded with water. The rocks are covered with sparse herbaceous vegetation. On the largest island, called Matykil, there are forb meadows, as well as small areas with dense shrubs. The height of the island above sea level is 700 meters. It is here that the largest bird market in the North Pacific is located. Scientists have counted about 10 million different birds here. These are: guillemots, auklets, guillemots, puffins, white belly, gulls, ipatka, cormorants, fulmars. The latter, there are about one million.

About 116 bird colonies, which are represented by fourteen species of sea birds, are located in the coastal zone of the Tauyskaya Bay. There are more than two million birds here.

Enumerate the locations of huge bird colonies can be endless. They are located along the entire coast of the Sea of ​​Okhotsk. About 147 species of seabirds live on Talan Island alone. Most of them use this place for rest, during long flights. 21 species live here permanently. Of these, only 11 species are seabirds. These are: gulls, puffins, guillemots, kittiwakes, auklets, ipatki, guillemots, white belly, cormorants and some others. Nests here and pretty rare bird- bald eagle.

Huge bird colonies are located on the rocky shores of the Pacific and Arctic Oceans. And this despite the fact that the nature here is quite harsh, and the vegetation is extremely poor. Snow can fall here even in July, and fogs and cold rains are considered a common occurrence. However, coastal waters abound marine life. Shellfish, shrimps, crustaceans, fish - all this attracts sea birds here like a magnet. There is plenty of food for them here, and the rocky and inaccessible shores are an ideal place for nesting.

Bird bazaars are massive (colonial) gatherings of birds (guillemots, gulls, fulmars, auks, etc.), as a rule, on the rocks of sea coasts. They are more common in the northern (polar) regions, on the oceanic islands of the southern hemisphere, less often along the coasts of the temperate and subtropical seas. Particularly large bird markets are formed on Novaya Zemlya, Franz Josef Land, on the Commander and Kuril Islands (guillemots, hatchets, ipatkas, white belly, ko-nugas, etc.). Sometimes in such bird markets the number of birds can reach 300-500 thousand individuals. Nesting in bird markets gives birds a number of advantages: lesser death of eggs and chicks from predators (seagulls and terns drive away arctic foxes and foxes together). Sometimes guano deposits are formed on the sea coasts - excrement of seabirds decomposed in a dry climate (Peru, Chile); often used as a valuable fertilizer.[ ...]

In the bird markets there is a colossal accumulation of birds. Nutrients play the main role here: bird droppings fall into the water: organic matter in the water is mineralized by bacteria, and therefore, in this place algae are concentrated. This in turn leads to an increase in the concentration of planktonic organisms, mainly crustaceans. The latter feed on fish, and on them the birds that inhabit the bazaars. Thus, bird droppings act here as an ecological factor. As an element of the environment, it is indivisible, but it does not act directly, but through complex system interaction of various environmental factors.[ ...]

Organisms form a system. They can form aggregations (colonies, shoals, prides, flocks, flocks, bird rookeries, camps) or be scattered. The habitat of a person can be scattered (a farm, a gatehouse, a manor, an estate) and compact (a camp, a camp, a settlement, a village, a town, a city, a capital).[ ...]

A kind of "gardens" of plankton are coastal annular currents washing steep cliffs with "bird colonies". It is estimated that in the Northern Hemisphere, guillemots alone can fertilize an area equal to that of the Barents Sea, producing up to 3 million tons of natural fertilizers per year.[ ...]

The burgomaster deservedly received his name from the Russian coast-dwellers in the Kola North, where these large gulls settle in bird markets and take tribute from birds in the form of eggs and chicks, take prey from other gulls and auks. In our north, burgomasters also destroy nests, catch ducklings and other chicks, and in general everyone they can overcome and catch, and also feed on carrion, pick up any edible sea waste. If the opportunity turns up, they catch fish and marine invertebrates. In general, they are very similar in nutrition to other large gulls. They also peck fish in nets, pick berries in the tundra.[ ...]

It should be noted that there are also incomplete biocenoses, for example, swamps, where some layers are often absent (primarily woody), tidal systems, bird colonies.[ ...]

negative moment Such settlements are the pollution of the central area with their waste, the trampling of vegetation, the compaction of the soil, etc., which is especially clearly observed in bird colonies. Too high a population density leads to conflict situations.[ ...]

Safe settlements are characterized by a large concentration of individuals in some area that is quite favorable for life. It can be an island in the middle of the ocean, wholly or partly occupied by a colony of birds (bird colonies), it can be a small grove inhabited by a population of birds (remember the accumulation of rooks in city cemeteries), anthills, termite mounds, bee hives, human cities - all these are examples of safe settlements. Aggregation in the central area provides the colony with its advantages: increased security, favorable conditions for mating, saving energy costs for life support due to specialization. At the same time, the entire influx of funds necessary for life comes from outside. The extraction of food takes place not at all in the central area, but in the vast space surrounding this area. In the case of high specialization, food is obtained by individuals specially designed for this, which are freed from other tasks, such as caring for offspring or protecting the settlement from enemies. These functions are performed by other "specialists", who receive for this everything they need for their own life support.[ ...]

In the Arctic deserts, the soil cover is observed only in the valleys of rivers and streams and on sea terraces, where the snow cover completely melts. Animal world poor in species: lemming, or pied, arctic fox, reindeer, polar bear. Found everywhere white partridge, polar owl. There are many bird markets on the rocky shores of the islands, where guillemots, white gulls, fulmars, eiders nest. The southern shores of Franz Josef Land, the western shores of Novaya Zemlya are a continuous bird colony.[ ...]

Animals also indirectly affect lichens by excreting excrement, compacting the soil, damaging substrates, etc. As is known, most lichens can exist in conditions where the supply of nitrates is extremely scarce, since many of them are able to fix atmospheric nitrogen or extract it from solutions washed out of the substrates by rainwater. But there is a special group of nitrophilic lichens, closely associated with nitrogenic habitats. Such lichens usually settle in places of bird colonies, on rocks covered with excrement of birds nesting here. Adaptation to nitrogenous habitats is associated primarily with the physiological adaptation of lichens, their ability, for example, to assimilate nitrogen in the form of ammonium. Under nitrogenous conditions, the thalli of scale lichens often grow strongly and take the form of small bushes.[ ...]

The areas of planned and current oil and gas developments have a high biodiversity index. 108 species of fish, 25 species of marine mammals live here, 11 of which are specially protected. Opposite Piltun Bay in the north-east of Sakhalin are the seasonal habitats of the Okhotsk-Korean population of gray whales, which are listed in the Russian and international Red Books and are on the verge of extinction. The population has about 100 individuals. To the south is a unique island. Tyuleniy, famous for rookeries of fur seals, sea lion seals and bird markets. Numerous lagoons and bays in the northeast of Sakhalin are nesting and stopping places along the migration routes of birds listed in the Russian and international Red Books. The main wealth of the Sakhalin shelf is numerous herds of salmon - pink salmon, coho salmon, chum salmon, sim, chinook salmon, most of which are "wild", i.e. emerged from caviar on natural spawning grounds. Other commercial species of fish also live here (pollock, herring, flounder, navaga, capelin, cod, smelt), crabs and shrimps, squids and sea ​​urchins. Even sturgeons are found in the north of Sakhalin.[ ...]

RESERVE (3.) - a temporarily protected natural area created to restore the population of one or more species of plants or animals, or to protect any interesting and rare natural objects. All species of plants and animals that are not included in the number of protected 3. can be used in accordance with environmental regulations. The share of 3. accounts for about 60% of the entire territory of the protected areas of the Russian Federation. There are 3. federal and regional subordination, their number is 68 and 2976, respectively. The main animals that are protected in 3.: beaver, elk, wild boar, roe deer, sable, muskrat, upland and waterfowl. In addition, some 3. are created to protect paleontological, geological and hydrological objects. The northernmost part of the country, 3. Franz Josef Land, with an area of ​​42,000 km2, was created to protect walruses, polar bears and various birds, including those that form large nests, the so-called bird markets. This 3. prohibits not only the fishing of protected animals, but also any harmful to nature economic activity(drilling to search for oil and gas, testing weapons, etc.).[ ...]

A population is a collection of individuals organized in a certain way. It has an age structure, that is, a certain ratio of the number of individuals of different ages. In animals, for example, juvenile (children), senile (senile, not participating in reproduction) and adult (individuals carrying out reproduction) groups are distinguished. The population is also characterized by a certain sex ratio, and, as a rule, the number of males and females is different (the sex ratio is not equal to 1:1). There are known cases of a sharp predominance of one sex or another, alternation of generations with the absence of males. Each population may also have a complex spatial structure (Fig. 2.11); subdivided into more or less large hierarchical groups - from geographical to elementary (micropopulation). Smaller stable groups are also distinguished, capable of crossing within themselves or within similar neighboring groups. Such are the prides of lions, packs of wolves and other representatives of the canine family, harems of pinnipeds, etc. Many species of birds have a colonial way of life (famous bird rookeries).[ ...]

Arctic (polar) deserts are terrestrial ecosystems that develop in extreme environmental conditions characterized by a lack of heat, widespread permafrost and ground glaciation, species poverty of communities, etc. They occupy the islands of Franz Josef Land, Severnaya Zemlya, the northern part of the Taimyr Peninsula, The Canadian archipelago, Greenland, etc. The climate here is very severe, and low air temperatures are combined with strong winds and significant air humidity. There is a special mode of solar radiation here, which is characterized by a long polar night and a polar day, which requires special adaptations of organisms for their life activity. So, on about. Franz Josef Land terrestrial glaciation occupies 85% of the island's area, in Greenland - about 80%, etc., and ice-free land areas are covered with sparse vegetation, represented mainly by lichens and mosses. On Franz Josef Land, the flora of flowering plants has only 50 species, while lichens and mosses - more than 200 species. Creeping and cushion-like life forms of plants predominate. Biomass of plants - less than 50 c/ha. The low productivity of vegetation is one of the reasons for the poverty of the animal world (lemmings, arctic fox, polar bear, and occasionally reindeer). However, the polar deserts are characterized by the so-called bird colonies, sometimes decorating this white silence. Seabirds are diverse: polar gull, snow bunting, thick-billed guillemot, little auk, silver tern, fulmar, etc. These ecosystems are very sensitive to anthropogenic impacts, therefore, the organization of various natural protected areas has begun here.

Part 1

There are four possible answers for each question. It is necessary to choose only one correct one and enter it into the matrix.

1. The kidney is:
   • a) rudimentary stem;
   • b) a modified sheet;
   • c) rudimentary escape;
   • d) a modified flower.
2. In order for the movement of xylem juice to occur under the action of root pressure, it is necessary:
   • a) sufficient content of mineral salts in the soil;
   • b) sufficient water content in the soil;
   • c) living cells of the root;
   • d) all of the above.
3. Angiosperms are grouped into families based on:
   • a) internal structure stem;
   • b) the structure of the root system;
   • c) leaf venation;
   • d) the structure of the flower and fruit.
4. Angiosperms, unlike gymnosperms, have:
   • a) sexual reproduction
   • b) cellular structure;
   • c) roots and shoots;
   • d) flower and fruit with seeds.
5. The intercellular spaces of the spongy tissue of the leaf are filled with:
   • a) water;
   • b) air;
   • c) air and water vapor;
   • d) carbon dioxide and water vapor.
6. Dioecious plants include:
   • a) bracken-fern;
   • b) pine;
   • c) an apple tree;
   • d) sea buckthorn.
7. Fungi have a higher organization compared to bacteria, as they have:
   • a) the ability to exchange substances and energy;
   • b) cellular structure;
   • c) nucleus and mitochondria;
   • d) the ability to enter into symbiosis with plants.
8. Wood does not include:
   • a) trachea;
   • b) sieve tubes;
   • c) fibers;
   • d) tracheids.
9. The physiological process of evaporation of water by a plant is called:
   • a) diffusion;
   • b) transpiration;
   • c) osmosis;
   • d) lower end motor.
10. Of the listed dry multi-seeded fruit is:
    • a) leaflet
    • b) lionfish;
    • c) achene;
    • d) walnut.
11. Annelids differ from roundworms in having:
    • a) the excretory system;
    • b) nervous system;
    • c) digestive system;
    • d) circulatory system.
12. Insects with incomplete metamorphosis include:
    • a) orthoptera, diptera;
    • b) dragonflies, homoptera;
    • c) Hymenoptera, Lepidoptera;
    • d) Hymenoptera, Homoptera.
13. Tapeworms differ from roundworms in that they lack:
    • a) the nervous system;
    • b) longitudinal muscles;
    • c) cuticles;
    • d) digestive system.
14. Worker bees are:
    • a) females that have laid eggs and started caring for offspring;
    • b) females developed from unfertilized eggs;
    • c) females in which the gonads are not developed;
    • d) young females capable of laying eggs for the next year.
15. Which of the following animals does not have a larval stage of development?
    • a) lamprey;
    • b) perch;
    • c) axolotl;
    • d) agile lizard.
16. Which of the formations by origin is not associated with the hairline?
    • a) whalebone
    • b) rhinoceros horn;
    • c) pangolin scales;
    • d) cat vibrissae.
17. What bones make up the chest of anurans?
    • a) only from ribs;
    • b) only from the ribs and sternum;
    • c) from the ribs, sternum and trunk vertebrae;
    • d) there is no chest.
18. The sternum is absent in:
    • a) grass frog;
    • b) quick lizard;
    • c) river perch;
    • d) platypus.
19. One circle of blood circulation is present in:
    • a) cod;
    • b) crested newt;
    • c) Nile crocodile;
    • d) stegocephalians.
20. The mammals of the Holarctic zoogeographic region include the following species:
    • a) platypus, wolf, marmot, roe deer;
    • b) beaver, bison, lynx, saiga;
    • c) lemming, camel, ermine, ring-tailed lemur;
    • d) ground squirrel, elk, jaguar, desman.

Part 2

You are offered tests with multiple choice answers(from 0 to 5). Indices of correct answers / Yes and incorrect answers / No indicate in the corresponding column of the matrix with an “X”.

1. Simple leaves:
   • a) tomato
   • b) elm;
   • c) hemp;
   • d) carrots;
   • e) clover.
2. The lily family includes:
   • a) peas;
   • b) wheat;
   • c) chamomile;
   • d) goose onion;
   • e) hazel grouse.
3. Multi-seeded fruit in:
   • a) corn
   • b) mountain ash;
   • c) cotton;
   • d) raspberries;
   • e) wheat.
4. The emergence of "bird markets" is due to the fact that:
   • a) there are not enough convenient places for nesting;
   • b) birds nesting here always hunt in large flocks;
   • c) it is easier for chicks to survive, since adult birds returning with prey
   • they feed not only their chicks, but everyone in a row;
   • d) in such clusters, the temperature of the environment is always higher, so less energy is spent on heating the chicks;
   • e) the collective protection of chicks from predators is more effective.
5. In representatives of the class of reptiles, the heart in its structure can be:
   • a) two-chamber;
   • b) three-chamber;
   • c) three-chamber with an incomplete septum in the ventricle;
   • d) four-chamber with a hole in the septum between the ventricles;
   • e) four-chamber.

Part 3

The task of determining the correctness of judgments. Enter the numbers of the correct judgments on the answer sheet.

1. Ephemera are herbaceous perennials with a short growing season.
2. Heliophytes are an ecological group of plants that exist in conditions of excess sunlight.
3. In fresh waters, you can meet representatives of bryophytes, ferns and gymnosperms.
4. All conifers and palms are evergreens.
5. Seed plants lack flagellar cells.
6. The micronucleus of ciliates is a diploid nucleus.
7. Rays and sharks are exclusively marine fish.
8. The metallic blue coloration of bird feathers is not due to the presence of pigments, but to their physical structure.
9. The limbs of insects consist of four sections.
10. At birds of prey with a lack of food resources, mainly older chicks receive food, while the younger ones die.

Part 4

1. Determine which classes the depicted representatives of arthropods belong to:

• A - crustaceans;
• B - chelicerate;
• B - insects;
• G - centipedes.

Enter your answers into the matrix.

2. The figures show modifications of the shoots. Match the drawings with the list of modifications:

1 - bulb; 2 - mustache; 3 - rhizome; 4 - corm; 5 - thorn.

Form for recording answers

Part 1

	2	3	4	5	6	7	8	9	10
11	12	13	14	15	16	17	18	19

Part 2

	1		2		3		4		5
	Yes	No	Yes	No	Yes	No	Yes	No	Yes

Part 3

Correct judgments: ___________________.

Part 4

Type of escape	1	2	3	4	5

Answers

Part 1

	2	3	4	5	6	7	8	9	10
	G	G	G	in	G	in	b	b	a
11	12	13	14	15	16	17	18	19
G	b	G	in	G	a	G	in	a

Part 2

	1		2		3		4		5
	Yes	No	Yes	No	Yes	No	Yes	No	Yes	No

I briefly mentioned the Bird Markets (near which, in fact, diving with guillemots took place). The phrase is quite well-known and generally intuitive. But, nevertheless, I suppose that not everyone knows what it really means ... And very few imagine how it all really looks like! Meanwhile, this amazing a natural phenomenon"and, moreover, quite rare on our planet ...

Bird colonies (sometimes also called "bird mountains") are massive colonial nests of seabirds, usually located on cliffs that drop steeply to the sea.

Their fundamental difference from any other bird colonies is that birds nest in close proximity to each other completely different types. Such a dense neighborhood provides a number of advantages: less death of eggs and chicks from predators, greater synchrony in breeding periods, etc. However, in fairness it should be noted that coexisting birds still differ somewhat in the choice of nesting sites, the set of food and the methods of obtaining them.

Such settlements usually arise where the waters of warm currents meet cold arctic ones. In the places of such "meetings" there are always a lot of microscopic plants and animals, fish... In other words, there is a lot of food, and therefore this is a very comfortable place for nesting.

The Barents Sea is home to some of the largest bird colonies in the world. They are located on the islands of Kharlov and Kuvshin, belonging to the Semiostrovie archipelago, which belongs to the Kandalaksha Reserve. The main population of these bazaars are guillemots and gulls - Mayevka. At the same time, gulls prefer about. Kharlov, and guillemots - Jug. On both islands there are also guillemots, little auks, puffins, burgomasters and some other birds.

So: in the lens of Bird's Bazaars, Fr. Jug!

It must be admitted that the Bird Markets are not called bazaars for nothing. Most of all, these clusters of birds resemble human bazaars, and, moreover, eastern ones ... Noise, constant movement, crowds of “people”, discordant cries, flapping wings, as well as howling wind, light rain and the sound of waves - here it is, the entourage of the local bazaar life! (The smell, by the way, is appropriate.) And all this is on absolutely sheer cliffs, where a person cannot always put a foot ... And the water under the rocks does resemble boiling soup - these are guillemots diving ...

Guillemots in general amazing birds... With their general plainness, the details of their lives are very, very interesting.

For example, they live in colonies and settle on ledges in a large crowd, tightly clinging to each other. At the same time, they choose a couple for themselves once and for the entire nesting season and are considered very good family men. They hatch eggs in turn, and when one partner replaces another, he often sits nearby for a long time, empathizing with the one who remains on duty, and only after some time flies away to warm up and feed! However, even in such strong families, betrayals happen !!! And a male or female returning after a walk can find his other half in the company of a “mistress / lover”, and, of course, this is followed by a scandal with dispersal. And since the birds are usually located in a dense crowd, the neighbors are also drawn into this showdown with pleasure !!!

The way of nesting of guillemots is also amazing. As such, they do not have nests, and they lay their eggs directly on stone ledges! Very hard and tough eggshell prevents the eggs from breaking, and the specific pear-shaped shape prevents them from falling even from an inclined surface. Although, nevertheless, in a crowd of birds, sometimes someone hurts and the eggs still fall. Under water, they look like small, neat pebbles.

With the advent of chicks, the population on each ledge increases. But not for long. Very soon after their “birth”, the chicks are ready to go down to the water. True, for this they need to jump from the sheer walls down into the sea! But this does not frighten them at all, light and fluffy, they plan down like small parachutes. Well, water is their native element.

The nesting period of guillemots is a short northern summer ... They arrive in these places around June, and in August the bazaars are already empty ... For wintering, birds fly to the sea, usually to Norwegian territorial waters and spend the whole winter on the water, almost never returning to the shore.

And in view of the conservation status of these places, tourists are allowed here for a short period of time in June-July, when the birds are sitting on their nests. It is believed that it was at this time that they most calmly react to the appearance of uninvited guests, who, however, are not particularly close anyway. Seeing the chicks is almost impossible, at this time the reserve is officially closed to the public.

I won’t lie if I say that this is one of the most interesting places in the world that I have seen with my own eyes ... I would love to visit those lands again (maybe even without diving), but, unfortunately, there are certain difficulties with organization, hopefully surmountable, sooner or later...

More photos for this story can be found here.

SUB-ORDER CLEANER (ALCAE)

FAMILY ALCIDAE

The largest species in the family was demonwinged auk(Pinguinus impennis). The mass of these birds reached 5 kg. They once bred in abundance on islands along the coasts of Europe and North America. Natural environmental causes brought this species to the brink of disaster, and the predatory collection of eggs and harvesting of adult birds by sailors led to its extinction. The last pair of auks and their egg were destroyed on a small island near Iceland in 1844. People have been actively hunting these auks since prehistoric times. Large accumulations of their bones have been found at ancient sites along the coasts of Europe to the Iberian Peninsula and North America to Florida.

Northern peoples, fishermen and whalers have long exploited bird colonies, harvesting mainly the eggs of auks. In some places they were even organized fishing. Now these crafts are almost everywhere stopped. Many bird markets in different countries commanded, including in our country. However, the number of auks has been greatly reduced in recent years. The reason for this is the mass death of birds from oil pollution of the sea. Particularly serious disasters occur in the Atlantic Ocean.

thick-billed, or short-billed, murre(Uria lomvia) is a medium-sized bird, its mass ranges from 780 to 1470 g.

The plumage is slate-black above, the sides of the head, chin and throat are chocolate-brown. The chest and belly are white. Each wing has a narrow white transverse stripe. In winter, the sides and bottom of the head become white.

The area of ​​distribution of this guillemot covers the north of Europe and Asia, Greenland and the Atlantic coast of North America, Kamchatka, the Kuril Islands, Sakhalin, Alaska and the Aleutian Islands.

The thick-billed murre settles on coastal rocks, as well as on flat islands, forming, together with other species, bird rookeries.

The number of thick-billed murre is high, especially in the northern parts of the range, where it forms huge nesting colonies. In the 20s and 30s. In the current century, 4 million birds nested on Novaya Zemlya.

In spring, guillemots return to their permanent nesting sites. This happens in April - May, after the coastal waters are free from ice.

The thick-billed murre nests on cornices and small ledges of high sheer coastal cliffs, and in some places on the even rocky surface of small islands, where there are no four-legged predators.

Occupation of nesting sites is accompanied by clashes between males and between females. Ledges and cornices 1-2 m wide, convenient for nesting, are occupied by guillemots with maximum density: the birds literally huddle together, covering the entire surface of the cornice.

Colonial instincts are expressed in guillemots to a very strong degree. They never nest in separate pairs away from bazaars. Small isolated colonies in several pairs must be surrounded by a large colony of kittiwakes or other birds. This is explained by the fact that the sexual activity of colonial birds is stimulated by the neighborhood and behavior of their comrades in the colony.

The emergence of coloniality in guillemots, as well as in other inhabitants of bird colonies, has other reasons. These include the lack of nesting-friendly coastal cliffs and the advantage in protecting offspring from predators.

In addition to guillemots, kittiwakes nest in bird markets, attaching their nests to small ledges of rocks. Razors often live in secluded corners of the bazaars. Along the edges of the bazaars, large glaucous gulls nest. Hoarse voices of guillemots, squeals of kittiwakes, sharp cries of large gulls - all these sounds made by tens and hundreds of thousands of birds merge into a continuous rumble that drowns out even the sound of the surf.

The desire of guillemots to nest in a tight heap leads to the fact that the central parts of the bazaars are populated with maximum density. In the center of the bazaars, fierce fights of guillemots break out every minute. Fighting birds act with a strong sharp beak and half-open wings, inflicting very sensitive blows on each other.

Having broken into pairs, guillemots begin to lay eggs. Mass oviposition occurs in the second half of May - the first half of June. The clutch consists of 1 large elongated pear-shaped egg with a thick shell. Egg sizes: 69-87x41-59 mm. The color of the eggs is from dark or bluish green to whitish with dark spots and strokes.

Murmurs do not make nests; eggs are placed on a bare eaves without any bedding. The pear shape gives the egg some stability I on the ledge.

Both parents incubate. When incubating, the guillemot presses the egg to the nest spot, and slips its paws from below. This compensates for the lack of litter. After 33-35 days, the first chicks hatch. They are covered with short, hard dark I down, more like wool. I chicks develop quickly, on the 15-20th day the fluff is completely replaced by a feather. Primary and tail feathers are absent in this plumage; they develop later, after the chick is launched into the water. Parents feed the chicks with small fish, bringing them food 2-3 times a day.

After 2-3 weeks, the chicks are already descending into the sea. Motivated by the cries of his parents, the guillemot stands for a long time on the edge of the ledge and finally decides to rush down. At the time of the jump, he stretches out, spreads his large webbed paws and small wings, making the last quick vibrating movements. From a height of 40-50 m, the chick usually manages to glide onto the water. Sometimes the chick falls on stones, but, as a rule, does not receive any damage.

Mass descent of chicks into the water in different parts of the range occurs on average during August. The descended chick sails with its parents into the sea. Such an early exit to the water is typical only for open-nesting guillemots. The reason for it can be seen in the preservation of chicks from large gulls, which watch in the bazaars of chicks that gape and are not protected by adult guillemots.

Winter migrations of thick-billed guillemots are insignificant. From the northern regions of the range, they move as ice advances to more southern ones. Guillemots migrate in small groups and, apparently, do not adhere to strictly defined migratory routes, dispersing randomly across the ocean.

Guillemots feed in the sea. The basis of their nutrition is small fish - cod, saury, capelin, herring, gerbil, etc. Invertebrates are used in a certain amount, mainly small crustaceans living in the water column.

The collection of eggs of the thick-billed murre in the bazaars, as well as the acquisition of the birds themselves, has long been carried out in many bazaars both in our country and abroad. Immoderate, and sometimes predatory fishing has led in some cases to a sharp reduction in the number of guillemots.

By appearance and biology is very close to the described species thin-billed, or long-billed, murre(U. aalge), which is characterized by a thinner and longer beak.

The slender-billed murre is widespread in the northern parts of the Atlantic and Pacific oceans. Unlike the thick-billed, it does not nest in the polar regions. It is numerous in Iceland, occupies a central place in the bazaars of the Murmansk coast, and is found in the Baltic Sea.

	Yakanovye
	colored snipes