Of the 400+ species recorded in Iowa over the years, the variety changes from season to season. Spring migration has the most diversity as birds quickly move north to their breeding grounds. Fall migration brings about an increase in diversity but is slower and spread out over several months. eBird bar charts are a great tool to learn about when to expect different species.

Avid birders sometimes attempt "Big Days" to record as many different species as possible in a twenty-four hour time period. Those are recorded and are presented here to give you an idea of seasonal changes and what to expect.