This is the time of year when the adult birds that arrived in spring are now combined with all the fledglings of the summer to create a peak population of birds in the northern hemisphere.
Peak Bird Mass in North America
Peak Bird Mass in North America
Peak Bird Mass in North America
This is the time of year when the adult birds that arrived in spring are now combined with all the fledglings of the summer to create a peak population of birds in the northern hemisphere.