Swifts fly to nesting sites last, and fly away first to winter. Rooks are the first to arrive in the spring and the last to fly away. How can you explain the differences in the timing of arrival and departure of birds? What signals do birds use in our geographic area to determine arrival and departure times?
In migratory birds, during the period of preparation for migrations, metabolism changes, leading to the accumulation of significant fat reserves with increased nutrition. The change in the nature of the metabolism that prepares the body for flight is provided by a combination of the internal annual rhythm of physiological processes and seasonal changes in living conditions, primarily, a change in the length of daylight hours (lengthening in spring and shortening in late summer). In addition, seasonal changes in feed are of great importance.
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