This 'conversion' chart stems from a comment overheard at Santa Ana National Wildlife Refuge, where there are no Downy Woodpeckers. In 2006, I led bird walks at Santa Ana and found myself reminding eastern birders that Texas is a whole new ballgame.
All of Texas is a funny place; it's where the bird life from the east meets west and north meets south. So this chart, geared mostly towards eastern US birders, will hopefully keep everyone on their toes. It's as simple as checking a white goose to see if it's Snow or Ross's, but on a regional level. Yes, Downy and Ladder-backed Woodpeckers (and Red-bellies and Golden-fronts and the gnatcatchers) will potentially stump those who bird by ear.
This is by no means an official, 100% foolproof list; birds have wings and don't bother to check the range maps. But I hope it at least points you in the right direction!
If it looks/sounds like..... Make sure it's not..... Because.....
|Mallard||Mexican Mallard||Mexican Mallard is expected|
|Turkey Vulture||Zone-tailed Hawk||Check every bird. Every time. Both absent in winter|
|Red-tailed Hawk||Swainson's Hawk||Swainson's in summer, Red-tail year round|
|Falcons||Aplomado, Prairie, kestrel||Report Aplomado sightings to The Peregrine Fund; they're reintroduced|
|Common Nighthawk||Lesser Nighthawk||Both present in summer; Lessers fly lower and seldom call|
|Chimney Swift||White-throated Swift||Chimneys should not be here|
|Ruby-throated Hummingbird||Black-chinned Hummingbird||...or Rufous, or Anna's, or Broad-tailed, or...|
|Red-bellied Woodpecker||Golden-fronted Woodpecker||Red-bellied should not be here|
|Say's Phoebe||Vermillion Flycatcher||Don't laugh, female/young Vermillions have been mistaken before|
|Great-crested or Brown-crested Flycatcher||Ash-throated Flycatcher||Ash-throated are summer residents, others are accidental|
|Western Kingbird||Cassin's Kingbird||Both are summer residents|
|Cliff Swallow||Cave Swallow||Cliffs may be abundant, but Caves are mixed in with them|
|Common Raven||Chihuahuan Raven||Both are present; larger size and deeper voice separate Common|
|Blue-gray Gnatcatcher||Black-tailed Gnatcatcher||Both present; Black-tails prefer dry scrub habitat in summer|
|Myrtle Yellow-rumped Warbler||Audubon's Yellow-rumped Warbler||Myrtle shouldn't be here|
|Summer Tanager||Hepatic Tanager||Just in case - especially in the mountains|
|Scarlet Tanager||Vermillion Flycatcher||Any Scarlet Tanager requires photo documentation!|
|Northern Cardinal||Pyrrhuloxia||Both present; look for Northern Cardinal in riparian habitats|
|Buntings||Indigo, Varied, Painted||Females will be frustrating, but definitely check all males!|
|Sparrows||Every Sparrow, Every Time||Beware: Cassin's, Rufous-crowned, Chipping, Clay-colored, Brewer's, Field, Vesper, Lark, Black-throated, Lark Bunting, Savannah, Grasshopper, Song, Lincoln's, White-crowned... and more!|
|Eastern Meadowlark||Western Meadowlark||Both are present; listen to voice for ID|
|Common Grackle||Brewer's Blackbird||Check for Red-winged and Yellow-headed, but in winter, Brewer's is default - Common grackles are rare!|
|Brown-headed Cowbird||Bronzed Cowbird||Both occur, Bronzed only in summer|
|Orioles||Orchard, Bullock's, Scott's||Summer residents; Hooded is a possibility as well|
|American Goldfinch||Lesser Goldfinch||Both occur; American in winter, listen for a slurred call for Lesser|
For bonus 'stump the birder' festivities, check out our "Large Brown Bird" post at SeeTrail. And keep in mind that exotic birds also occasionally fall into the description trap... emu, anyone?