This video from the USA is called Swainson’s Warbler.
From Wildlife Extra:
Rare warbler on the increase in USA
The results of the study, which compiled data from 20 years of field studies, suggests that if current trends continue, forests managed as short-rotation pine plantations will support the majority of Swainson’s warbler breeding populations by the end of the 21st century.
The Swainson’s warbler has been a high conservation concern for decades as its 90,000 breeding individuals are sparsely distributed across 15 states in the USA.
The rarity of the Swainson’s warbler was previously blamed on its finicky preference for large areas of densely vegetated breeding habitat in the southeastern U.S. and wintering range in the Caribbean basin. However research carried out in the 1990s revealed that this warbler could be found in a surprisingly wide spectrum of habitats, including young loblolly pine plantations in eastern Texas.
The researchers believe the short-rotation pine plantations have a seven-to-eight-year window when the plantations are dense enough to support populations of Swainson’s warbler. Once this period ends and the plantations thin out, Graves believes that the warblers will likely relocate to nearby younger plantations that exhibit the desired foliage density.
“The Swainson’s warbler is becoming a conservation success story in a habitat that was once feared to be a biological desert,” said lead author Gary Graves from Smithsonian’s National Museum of Natural History in the USA.
“This is a prime example of how intensive management of forest lands for industrial purposes can have a direct impact on bird populations in a positive way.”
The Swainson’s warbler a small olive-brown bird with pale yellowish-white underparts that measures approximately 5.5 inches long and is known for its loud, distinctive song and secretive behaviour. Despite its small size, male Swainson’s warblers defend large territories that range in size from 3 to 18 hectares.