In Yasukawa' s month-long study of blackbirds, the percentage of smaller birds that survived the duration of the study exceeded the percentage of larger birds that survived
However, Yasukawa' s conclusion that size is a determinant of a blackbird' s chances of survival over a month-long period is probably mistaken, since smaller blackbirds are generally younger than larger ones
With a larger sample of blackbirds, the percentage of smaller birds that survive a one-month period would be the same as the percentage of larger birds that survive.