On Monday Kendra saw 5 sites x 7 birds/site = <<5*7=35>>35 different birds
On Tuesday Kendra saw 5 sites x 5 birds/site = <<5*5=25>>25 different birds
On Wednesday Kendra saw 10 sites x 8 birds/site = <<10*8=80>>80 different birds
In total Kendra saw 35 birds + 25 birds + 80 birds = <<35+25+80=140>>140 different birds
In total Kendra visited 5 sites + 5 sites + 10 sites = <<5+5+10=20>>20 sites.
On average Kendra saw 140 birds / 20 sites = <<140/20=7>>7 different birds at each site
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