ANCHORAGE, Alaska (AP) — A federal study says more shrubs growing on Arctic tundra likely will have little effect on the abundance of most bird species until the vegetation grows tall.
The study by U.S. Geological Survey researchers says the height of shrubs growing on tundra is a critical factor in whether birds will stick around.
Research wildlife biologist Sarah Thompson says the study looked at 17 bird species on Alaska's Seward Peninsula over three breeding seasons.
She says multiple studies have shown tundra getting "shrubbier" as the climate continues to warm and the growing season expands.
Thompson says the research didn't explain why tall shrubs made tundra less appealing to birds.
She says the study was aimed at assessing how birds may exist as habitat changes with future climate warming.