What is the expected effect on variation from a founder effect occurring in a small population of birds?

The founder effect occurs when a small group from a larger population establishes a new population in a different location. This small group may not represent the genetic diversity of the original population due to its limited size. As a result, the new population is likely to have reduced genetic variation compared to the source population. This decrease in variation is primarily because the genes in the founding individuals constitute only a subset of the total genetic diversity present in the larger population.

When a small number of individuals found a new population, certain alleles may be overrepresented or underrepresented simply due to chance. Additionally, if the founding group possesses specific traits or characteristics that differ from the original population, these traits may become more pronounced in subsequent generations. Consequently, inbreeding and genetic drift can further exacerbate the loss of variation over time. A smaller gene pool means fewer genetic combinations are possible, leading to an overall decrease in variation within that population.