Populations are highly mobile, both in terms of long term movements of individuals relocating their place of residence as well as shorter term mobility such as commuting, seasonal travel and recreational trips. Working with call detail record data from Namibia and Senegal, we study population migration and its link to short term movement. We compare the short term mobility estimates extracted from call detail records to census data in the two countries and find a strong annual relationship, as well as distinct daily patterns in the relationship between long and short term movement.