DEAR JOAN: A female house finch, I believe, that has been visiting our backyard feeders for several days in a row, has a very deformed beak. It appears that her lower beak is grossly long and her ...
How do you know that finches' beak depth is heritable? You can see from Figure 2 that there is a correlation between the parents' and offsprings' beak size. How did the finch population change from ...