NEET BIOLOGY

Detailed explanation-1: -The barn swallow nest is constructed taking mud which is mixed with grass. The swallow bird nest is generally 2 inches deep and 3 inches in diameter and is built on a horizontal surface. Once the nest is all set and ready, the swallow lines it with feathers, grass and lightweight plastic on the inside.

Detailed explanation-2: -Swallows are small birds with dark, glossy-blue backs, red throats, pale underparts and long tail streamers. They are extremely agile in flight and spend most of their time on the wing. They are widespread breeding birds in the Northern Hemisphere, migrating south in winter.

Detailed explanation-3: -Both male and female build the nest cup using mud. They collect mud in their bills and often mix it with grass stems to make pellets. They first construct a small shelf to sit on, then build up the nest’s sides. If built against a wall or other vertical surface the result is a semicircular, half-cup shape.

Detailed explanation-4: -Swallows prefer outbuildings which provide dark ledges and nooks and crannies for nesting. These are cosy in cold weather and cool when it is hot. Swallows can enter a building through a very small hole and need very little light. Brightly lit nest sites are most at risk from predators.