60 birds were recorded seen in Idaho in September in our iNaturalist sample; 5 of the top 50 are at their peak this month. The list is ranked by number of research-grade observations.
Top birds in September

Mallard
Swainson's Hawk

Red-tailed Hawk

White-crowned Sparrow

Great Blue Heron

Ring-billed Gull

Black-capped Chickadee
Canada Goose
Black-billed Magpie

Wild Turkey

Osprey

Northern Flicker
All birds seen in Idaho in September
| # | Species | Scientific name | Family | Obs. | Peak in state |
|---|---|---|---|---|---|
| 1 | Mallard | Anas platyrhynchos | Ducks, Geese, and Swans | 262 | Apr (past peak) |
| 2 | Swainson's Hawk | Buteo swainsoni | Hawks, Eagles, and Kites | 220 | Aug (past peak) |
| 3 | Red-tailed Hawk | Buteo jamaicensis | Hawks, Eagles, and Kites | 216 | Mar (past peak) |
| 4 | White-crowned Sparrow | Zonotrichia leucophrys | New World Sparrows | 207 | Sep (peak) |
| 5 | Great Blue Heron | Ardea herodias | Herons, Egrets, and Bitterns | 148 | Apr (past peak) |
| 6 | Ring-billed Gull | Larus delawarensis | Gulls, Terns, and Skimmers | 146 | Feb (past peak) |
| 7 | Black-capped Chickadee | Poecile atricapillus | Tits, Chickadees, and Titmice | 144 | Apr (past peak) |
| 8 | Canada Goose | Branta canadensis | Ducks, Geese, and Swans | 138 | Apr (past peak) |
| 9 | Black-billed Magpie | Pica hudsonia | Crows, Jays, and Magpies | 135 | May (past peak) |
| 10 | Wild Turkey | Meleagris gallopavo | Pheasants, Grouse, and Allies | 128 | Apr (past peak) |
| 11 | Osprey | Pandion haliaetus | Ospreys | 117 | Apr (past peak) |
| 12 | Northern Flicker | Colaptes auratus | Woodpeckers | 115 | Mar (past peak) |
| 13 | Red-breasted Nuthatch | Sitta canadensis | Nuthatches | 112 | Sep (peak) |
| 14 | Double-crested Cormorant | Nannopterum auritum | Cormorants and Shags | 111 | Apr (past peak) |
| 15 | Cooper's Hawk | Astur cooperii | Hawks, Eagles, and Kites | 111 | Apr (past peak) |
| 16 | Turkey Vulture | Cathartes aura | New World Vultures | 108 | Apr (past peak) |
| 17 | American Kestrel | Falco sparverius | Falcons and Caracaras | 106 | Jan (past peak) |
| 18 | Yellow-rumped Warbler | Setophaga coronata | New World Warblers | 103 | May (past peak) |
| 19 | American White Pelican | Pelecanus erythrorhynchos | Pelicans | 99 | Jun (past peak) |
| 20 | American Robin | Turdus migratorius | Thrushes | 99 | Mar (past peak) |
| 21 | Song Sparrow | Melospiza melodia | New World Sparrows | 98 | Apr (past peak) |
| 22 | Bald Eagle | Haliaeetus leucocephalus | Hawks, Eagles, and Kites | 97 | Jan (past peak) |
| 23 | American Coot | Fulica americana | Rails, Gallinules, and Coots | 96 | Apr (past peak) |
| 24 | Great Horned Owl | Bubo virginianus | Typical Owls | 96 | Apr (past peak) |
| 25 | Dark-eyed Junco | Junco hyemalis | New World Sparrows | 91 | Jan (past peak) |
| 26 | California Quail | Callipepla californica | New World Quails | 87 | May (past peak) |
| 27 | Great Egret | Ardea alba | Herons, Egrets, and Bitterns | 84 | Sep (peak) |
| 28 | Western Grebe | Aechmophorus occidentalis | Grebes | 83 | May (past peak) |
| 29 | Killdeer | Charadrius vociferus | Plovers and Lapwings | 82 | May (past peak) |
| 30 | Cedar Waxwing | Bombycilla cedrorum | Waxwings | 71 | Jun (past peak) |
| 31 | Belted Kingfisher | Megaceryle alcyon | Kingfishers | 69 | Jan (past peak) |
| 32 | Common Merganser | Mergus merganser | Ducks, Geese, and Swans | 69 | Apr (past peak) |
| 33 | Savannah Sparrow | Passerculus sandwichensis | New World Sparrows | 69 | Sep (peak) |
| 34 | European Starling | Sturnus vulgaris | Starlings | 69 | Apr (past peak) |
| 35 | Brewer's Blackbird | Euphagus cyanocephalus | New World Blackbirds and Orioles | 67 | May (past peak) |
| 36 | Wood Duck | Aix sponsa | Ducks, Geese, and Swans | 64 | Nov (rising) |
| 37 | California Gull | Larus californicus | Gulls, Terns, and Skimmers | 63 | Mar (past peak) |
| 38 | American Crow | Corvus brachyrhynchos | Crows, Jays, and Magpies | 63 | Mar (past peak) |
| 39 | House Finch | Haemorhous mexicanus | Finches, Euphonias, and Allies | 62 | Apr (past peak) |
| 40 | Ruby-crowned Kinglet | Corthylio calendula | Kinglets | 62 | Apr (past peak) |
| 41 | Eurasian Collared-Dove | Streptopelia decaocto | Pigeons and Doves | 60 | Apr (past peak) |
| 42 | Northern Harrier | Circus hudsonius | Hawks, Eagles, and Kites | 58 | Mar (past peak) |
| 43 | Mourning Dove | Zenaida macroura | Pigeons and Doves | 57 | Apr (past peak) |
| 44 | Mountain Bluebird | Sialia currucoides | Thrushes | 57 | Jun (past peak) |
| 45 | Ruffed Grouse | Bonasa umbellus | Pheasants, Grouse, and Allies | 56 | Sep (peak) |
| 46 | Downy Woodpecker | Dryobates pubescens | Woodpeckers | 56 | Apr (past peak) |
| 47 | Western Tanager | Piranga ludoviciana | Cardinals and Allies | 55 | Jun (past peak) |
| 48 | Sandhill Crane | Antigone canadensis | Cranes | 53 | Apr (past peak) |
| 49 | Clark's Nutcracker | Nucifraga columbiana | Crows, Jays, and Magpies | 51 | Aug (past peak) |
| 50 | American Goldfinch | Spinus tristis | Finches, Euphonias, and Allies | 51 | May (past peak) |