60 birds were recorded seen in District of Columbia in May in our iNaturalist sample; 17 of the top 50 are at their peak this month. The list is ranked by number of research-grade observations.
Top birds in May

Mallard

American Robin

House Sparrow

European Starling
Gray Catbird

Northern Cardinal

Common Grackle

Great Blue Heron
Canada Goose

Northern Mockingbird

Blue Jay

Mourning Dove
All birds seen in District of Columbia in May
| # | Species | Scientific name | Family | Obs. | Peak in state |
|---|---|---|---|---|---|
| 1 | Mallard | Anas platyrhynchos | Ducks, Geese, and Swans | 588 | Apr (past peak) |
| 2 | American Robin | Turdus migratorius | Thrushes | 403 | Apr (past peak) |
| 3 | House Sparrow | Passer domesticus | Old World Sparrows | 359 | Apr (past peak) |
| 4 | European Starling | Sturnus vulgaris | Starlings | 341 | Apr (past peak) |
| 5 | Gray Catbird | Dumetella carolinensis | Mockingbirds and Thrashers | 242 | Jun (rising) |
| 6 | Northern Cardinal | Cardinalis cardinalis | Cardinals and Allies | 217 | Apr (past peak) |
| 7 | Common Grackle | Quiscalus quiscula | New World Blackbirds and Orioles | 188 | Apr (past peak) |
| 8 | Great Blue Heron | Ardea herodias | Herons, Egrets, and Bitterns | 180 | May (peak) |
| 9 | Canada Goose | Branta canadensis | Ducks, Geese, and Swans | 179 | May (peak) |
| 10 | Northern Mockingbird | Mimus polyglottos | Mockingbirds and Thrashers | 166 | Apr (past peak) |
| 11 | Blue Jay | Cyanocitta cristata | Crows, Jays, and Magpies | 162 | Jun (rising) |
| 12 | Mourning Dove | Zenaida macroura | Pigeons and Doves | 158 | Apr (past peak) |
| 13 | Red-winged Blackbird | Agelaius phoeniceus | New World Blackbirds and Orioles | 128 | Apr (past peak) |
| 14 | Osprey | Pandion haliaetus | Ospreys | 114 | Apr (past peak) |
| 15 | Brown-headed Cowbird | Molothrus ater | New World Blackbirds and Orioles | 106 | May (peak) |
| 16 | Eastern Kingbird | Tyrannus tyrannus | Tyrant Flycatchers | 99 | May (peak) |
| 17 | Carolina Wren | Thryothorus ludovicianus | Wrens | 85 | Apr (past peak) |
| 18 | Wood Duck | Aix sponsa | Ducks, Geese, and Swans | 80 | Apr (past peak) |
| 19 | Black-crowned Night Heron | Nycticorax nycticorax | Herons, Egrets, and Bitterns | 79 | May (peak) |
| 20 | House Finch | Haemorhous mexicanus | Finches, Euphonias, and Allies | 66 | May (peak) |
| 21 | Great Crested Flycatcher | Myiarchus crinitus | Tyrant Flycatchers | 65 | May (peak) |
| 22 | Cedar Waxwing | Bombycilla cedrorum | Waxwings | 62 | May (peak) |
| 23 | Common Yellowthroat | Geothlypis trichas | New World Warblers | 56 | Sep (rising) |
| 24 | Yellow-crowned Night Heron | Nyctanassa violacea | Herons, Egrets, and Bitterns | 55 | Jun (rising) |
| 25 | Indigo Bunting | Passerina cyanea | Cardinals and Allies | 55 | May (peak) |
| 26 | Pileated Woodpecker | Dryocopus pileatus | Woodpeckers | 55 | Apr (past peak) |
| 27 | Red-tailed Hawk | Buteo jamaicensis | Hawks, Eagles, and Kites | 52 | Jan (past peak) |
| 28 | American Goldfinch | Spinus tristis | Finches, Euphonias, and Allies | 52 | Aug (rising) |
| 29 | Song Sparrow | Melospiza melodia | New World Sparrows | 50 | Mar (past peak) |
| 30 | Double-crested Cormorant | Nannopterum auritum | Cormorants and Shags | 50 | Apr (past peak) |
| 31 | Red-shouldered Hawk | Buteo lineatus | Hawks, Eagles, and Kites | 49 | Jan (past peak) |
| 32 | Blue-gray Gnatcatcher | Polioptila caerulea | Gnatcatchers and Gnatwrens | 48 | Apr (past peak) |
| 33 | Barn Swallow | Hirundo rustica | Swallows and Martins | 48 | May (peak) |
| 34 | Red-bellied Woodpecker | Melanerpes carolinus | Woodpeckers | 48 | Mar (past peak) |
| 35 | Scarlet Tanager | Piranga olivacea | Cardinals and Allies | 47 | May (peak) |
| 36 | Wood Thrush | Hylocichla mustelina | Thrushes | 47 | May (peak) |
| 37 | Yellow-rumped Warbler | Setophaga coronata | New World Warblers | 45 | Oct (rising) |
| 38 | Downy Woodpecker | Dryobates pubescens | Woodpeckers | 45 | Mar (past peak) |
| 39 | Northern Flicker | Colaptes auratus | Woodpeckers | 44 | Apr (past peak) |
| 40 | Bald Eagle | Haliaeetus leucocephalus | Hawks, Eagles, and Kites | 43 | Mar (past peak) |
| 41 | Black-and-white Warbler | Mniotilta varia | New World Warblers | 43 | Sep (rising) |
| 42 | Swainson's Thrush | Catharus ustulatus | Thrushes | 43 | May (peak) |
| 43 | Red-eyed Vireo | Vireo olivaceus | Vireos, Shrike-Babblers, and Erpornis | 43 | May (peak) |
| 44 | Baltimore Oriole | Icterus galbula | New World Blackbirds and Orioles | 41 | May (peak) |
| 45 | American Redstart | Setophaga ruticilla | New World Warblers | 38 | Sep (rising) |
| 46 | Eastern Phoebe | Sayornis phoebe | Tyrant Flycatchers | 37 | Apr (past peak) |
| 47 | Magnolia Warbler | Setophaga magnolia | New World Warblers | 37 | May (peak) |
| 48 | Green Heron | Butorides virescens | Herons, Egrets, and Bitterns | 35 | Jul (rising) |
| 49 | Tree Swallow | Tachycineta bicolor | Swallows and Martins | 35 | Apr (past peak) |
| 50 | Ovenbird | Seiurus aurocapilla | New World Warblers | 35 | May (peak) |