Question

The white-tailed ptarmigan lives at high elevations on mountains that receive a lot of snow in the winter. During the summer, the ptarmigans’ feathers are mottled brown. The birds lose the brown feathers and grow a new set of white feathers during the winter. Scientists are concerned that rising global temperatures will affect the white-tailed ptarmigan. If global climate change leads to the elimination of snow in the habitat of white-tailed ptarmigans, which adaptation is most likely to occur over many generations? A.Birds with white feathers in areas without winter snow will be easier for predators to find. Over time this could lead to white-tailed ptarmigans that have brown feathers throughout the year. B.Birds with brown feathers in areas without winter snow will be easier for predators to find. Over time this could lead to white-tailed ptarmigans that have white feathers throughout the year. C.Birds with white feathers will be easier to see on the ground in the summer. Over time this could lead to white-tailed ptarmigans that have white feathers throughout the year. D.Birds with brown feathers will be easier to see on the ground in the winter. Over time this could lead to white-tailed ptarmigans that have brown feathers throughout the year.

Answer 1

A. Birds with white feathers in areas without winter snow will be easier for predators to find. Over time this could lead to white-tailed ptarmigans that have brown feathers throughout the year.

Step-by-step explanation:

As stated explicitly in the passage, the white snow allows for easier survival of the ptarmigans who have white feathers covering their whole body. Despite their feathers becoming mottled brown in summers, they shed those brown feathers and grew white feathers in the winters.

This regrowth of white feathers is to offer them better 'concealment' from predators, for their feathers will be the same as those white snows and thus, making it difficult for any predators to locate them quickly. But if the global temperature continues rising rapidly, then the snows will melt and leave the birds vulnerable, with no chance of survival. The elimination of the snow in their habitat will make them easy targets, with their white feathers easily visible amidst the brown mountains instead of the white snow-covered mountains.

Thus, the correct answer is that birds with white feathers will be easier for predators to find in areas where there is no winter snow. This could then lead to white-tailed ptarmigans with brown feathers throughout the year.