Nesting of the common redstart

In the context of ever-increasing anthropogenic impact on nature, the issues of protection and rational use of animal resources are becoming extremely relevant. In this regard, timely assessment of the state of the population, identification of the main trends in changes in the animal population globally and regionally are of paramount importance (Sokolov et al. 1978, Syroechkovsky, Rogacheva, 1978, Ravkin 1979, Sokolov 1979). Particularly important research is the region where, due to the harsh climate, ecosystem reserves are not large, and the consequences of human economic activity are difficult to predict.

The study of the ecology and biology of nesting birds in the Dzhegalakh area has its own characteristics that are of scientific and practical interest. We think that the study and observation of the avifauna of Dzhegalakh provides new useful material.

Based on this, we have identified the object of study: nesting of a rare bird species.

Conditions for nesting birds in Yakutia

Temperature conditions: The entire territory of Yakutia is characterized by a sharply continental climate and short summers. The duration of the frost-free period is 100, in Yakutsk 95 days.

The average date of the onset of spring (the transition of the average daily temperature is -5C) in the Suntarsky ulus falls on April 14. After about 10 days, the daily average crosses 0 C. The snow melts in the first ten days of May.

Precipitation: the total annual precipitation does not exceed 300 ml, which corresponds to our zone. Of these, more than 50% occur in the summer months. Spring and the first half are usually dry, with 16–23 mm falling in May, 29–40 mm in June, and 40–45 mm in July. precipitation. In the first half of May, short-term snowfalls and mixed precipitation, which, combined with strong winds, negatively affect the foraging activities of most bird species. With the exception of this phenomenon, nesting conditions for this indicator are generally favorable.

Wind: in Suntar, according to long-term data, the following number of days with strong winds (above 10 m/s) is observed: in April - 6, in May - 8, in June - 8, in July - 8, in August - 4 days. Strong winds undoubtedly have a negative effect on birds that obtain food on the fly and by soaring, as well as on species that have large nesting structures in trees.

Hydrological regime: high flood levels and its protracted nature limit nesting sites, which negatively affects the reproduction of many bird species. In particular, A.A. Maksimov (1974) showed that a prolonged flood leads to a general reduction in the numbers of many species and completely eliminates the possibility of nesting for early arriving birds. However, the most harmful for already nesting birds is the repeated summer rise of water, some years exceeding the level of the spring flood. The feeding conditions of birds largely depend on the nature of the spills.

Feeding conditions: the characteristics of nesting birds are largely determined by feeding conditions. More than 1000 vascular plant species grow on the territory of Yakutia (Karavaev, 1965; Karavaev, Skryabin 1971). A significant part of the flora consists of herbaceous plants, the seeds of which play a particularly important role in the nutrition of birds during migration. Some berries are preserved and some birds feed on them after winter. Seeds of tree species are important for sedentary and nomadic birds (Dektyarev, Illarionov, Germagenov, Sidorov, 1980).

Anthropogenic factors: the significance of direct and indirect human influence on the fauna of nesting birds is determined by the dense population of the region. Burning and mowing of grasses is widespread, covering almost all areas of floodplain meadows. Spring fires, destroying rags in the meadows and reed thickets, worsen their nest and protective conditions. In a dry spring, fires and agricultural burns can completely destroy nests not only on the ground, but also on trees and bushes. One of the most negative factors for the life of birds nesting on the ground and not high above it is grazing by livestock. Intensive grazing destroys almost all clutches of meadow and forest edge birds.

Enemies: the natural enemies of nesting birds are small predatory animals. However, they can have a certain effect on birds only during a period of acute shortage of the main types of food - mouse-like ones. One of the most dangerous enemies of birds are ravens.

Characteristics of the reservoir and area of Dzhegalakh

The area of Djegalakh in the area with the lake occupies a small area of about 6.84 km2. A swampy lake stretches over an area of approximately 1.6 km2, providing convenient nesting sites for waterfowl: mallards, pintails, and black-headed gulls. The length of Lake Dzhegalakh is 1.5 km, width – 0.7 km. Almost on all sides there is a mixed forest: larch and spruce. The lake has poor coastal vegetation. More or less significant thickets of coastal vegetation are confined to the shores of wind-protected bays and forest streams. However, the poverty of the surface flora here is compensated by the abundance of phyto- and zooplankton. The lake water appears like a mushy liquid in summer. What is found in abundance in this water provides a good food supply for waterfowl, which is a good condition for nesting.

The dominant type of vegetation in the Dzhegalakh area is forest, which occupies about 60% of the area. In larch forests and spruce forests, the undergrowth is poorly developed and in the most humid places it consists of wild rosemary, moss and lingonberries, and along the edges of meadows - from Siberian juniper. The spruce here grows in a ring, forming the edge of the forest.

A lot of residential buildings have recently appeared in the Dzhegalakh area. Almost all residents have livestock.

The presence of a lake, the edge of a forest, and residential buildings create favorable conditions for nesting of many species of birds.