Learning the songs of warblers can be a great help in locating and identifying them during the spring. Many skilled birders identify warblers by song before they see the singer, and sometimes, they hear warblers without seeing them. Not all warblers vocalize, so you cannot rely only on song. This is especially true during the latter stages of the spring migration when an increasing number of non-vocalizing females visit the park. Warblers sometimes vocalize during the fall migration, but much less frequently.
Some warblers have simple mnemonics to help a birder to remember their song, such as the Hooded Warbler's I wanna rent a video. Unfortunately, most warblers do not, which can make learning warbler song difficult. For space reasons and to avoid confusing people, the examples on most commercial birdsong recordings (and listed below) are the most common song or songs of each warbler, even though a species can have many different vocalizations. For instance, the Cornell Lab's comprehensive set of recordings for the birds of North America has 18 different Magnolia Warbler songs and calls, and some sound distressingly like the vocalizations of other species.
One day when I was at Monticello Park, I heard a song I could not identify. I found the singer, who turned out to be a Common Yellowthroat. A bit later, other people came to the park while the bird was still singing. They asked about the song, and I told them it was a Common Yellowthroat. They did not believe me, and after they went and found the bird, they said, "It's a yellowthroat".
Learning birdsong is easier if you have musical skills. I have a relative who was a concert violinist with perfect pitch. She does not know much about birds, but once when she was on a nature walk, she would hear a birdsong and say, "That bird is singing in C-sharp." I lack her musical ability, so I need to find other methods for remembering.
The loudness of a song might give you a clue about how high a bird is likely to be. Birds who stay on or near the ground sing louder, because sound does not travel as well on the forest floor. Birds who spend most of their time in the treetops are more likely to have quiet songs, because there are fewer impediments to block the sound. Some of the quiet songs from the treetops can be difficult to hear.
At Monticello Park in the spring, two of the more difficult warbler songs are the ones you are likely to hear most frequently: the Yellow-rumped Warbler during the first half of migration, and the American Redstart during the second half. The 2015 Stephenson and Whittle Warbler Guide presents a phrase for each species which is characteristic of the song. For instance, they want you to remember the trill of the Yellow-rumped Warbler with the phrase, "Sitting on your rump, mumbling the same Phrases, never makes a strong point". This system does not work for me, because I have more trouble remembering the phrase than remembering the song itself. They characterize the song of the American Redstart as, "American red team starts with 4 running steps, then jumps up/down for success". When I hear an American Redstart song, I count to five very quickly, because that is roughly how many notes the song has. One song goes ZEE-ZEE-ZEE-ZEE-o, with the last syllable dropping off, but this is one of many redstart songs.
Some of the best recordings for learning warbler songs are from the Peterson Field Guide Series. Richard Walton's and Robert Lawson's Birding by Ear has 10 warbler species, and More Birding by Ear has an additional 25. You also should spend time listening to birdsong in the field. Don't be discouraged if you can't identify certain songs. Learning warbler songs is difficult and takes a lot of practice. And don't be afraid to ask for assistance from other birders. Most birders will be glad to help you.
Below are descriptions of the warbler songs heard at Monticello Park, along with hyperlinks to the Cornell Lab webpages where you can listen to the vocalizations.
Here are the songs of the Yellow-rumped Warbler and American Redstart.
Yellow-rumped Warbler - A variable loose trill, usually with two parts
American Redstart - A short, sharp, quick phrase, usually with about five notes
Some warblers have mnemonics or song qualities that are relatively easy to learn.
Black-throated Blue Warbler - I'm so la-ZEE or beer-beer-beer-BEE
Yellow Warbler - A perky sweet, sweet, sweet, a little more sweet
Common Yellowthroat - witchety-witchety-witchety
Ovenbird - teacher - teacher - teacher which gets progressively louder
Hooded Warbler - I wanna rent a video or A-Whee-Ta-Whee-Ta-Whee-Teo
Black-throated Green Warbler - Daytime song is zee-zee-zee-zoo-zee; dawn or aggressive song is Trees, Trees, Murmuring Trees
Chestnut-sided Warbler - Pleased Pleased Pleased to Meetcha
Magnolia Warbler - Like a truncated Chestnut-sided song — Pleased to MEET-cha
Mourning Warbler - A burry Pleased Pleased Pleased to MEET-cha — the burriness is more important than what the bird is singing
Kentucky Warbler - churry-churry-churry — it is loud and can be confused with a Carolina Wren
Prairie Warbler - Song that goes up the musical scale
Blue-winged Warbler - Bee-Buzz or Bee-Buzz-Buzz
Golden-winged Warbler - Bee-Buzz-Buzz-Buzz — some Blue-winged Warblers put one or more extra buzzes on the end, and the hybrid warblers of the two species also might sing a song with more than one buzz
Some warblers have short songs. The last three are soft and usually sung from high in the trees, so they can be difficult to hear.
Black-and-white Warbler - Sounds like a squeaky wheel - wee-sa, wee-sa, wee-sa, wee-sa
Canada Warbler - Variable, short, and abrupt, sometimes sounding like Fie dippety, swee ditchety
Blackpoll Warbler - Sounds like tinkling wind chimes — an important song to know toward the end of the migration
Bay-breasted Warbler - A high-pitched tee-see tee-see tee-see, like a Black-and-white, but shorter
Cape May Warbler - A high-pitched tink-tink-tink-tink-tink
Some of the more difficult warbler songs involve trills.
Pine Warbler - A loose musical trill with a soft, lazy quality — it can be confused with Chipping and Swamp Sparrows and Dark-eyed Juncos
Palm Warbler - A weak buzzy trill
Wilson's Warbler - A slow trill that drops off at the end
Worm-eating Warbler - A dry insect-like trill
Northern Parula - A buzzy trill that gets progressively louder and then drops over the top — the last drop-off makes it fairly easy to identify
Cerulean Warbler - Four quick buzzy notes, leading to a buzzy trill at the end
Blackburnian Warbler - A series of two-note phrases with a thin high-pitched final phrase which can be difficult to hear from the treetops
Nashville Warbler - A two-part see-bit see-bit see-bit see see see see, with the last phrases sounding like a slow trill
Some warbler songs are long and complex.
Tennessee Warbler - 3-part thucka-thucka-thucka-swit-swit-chew-chew-chew-chew
Louisiana Waterthrush - Long slurred introductory whistles at the beginning which descend into a jumble of quieter notes
Northern Waterthrush - Loud and evenly paced, with a CHEW-CHEW-CHEW at the end
Some warblers are infrequently seen at Monticello and even less frequently heard, but here are their songs.
Prothonotary Warbler - The only bird who sings Tweet-tweet-tweet-tweet-tweet
Orange-crowned Warbler - A staccato trill that falls at the end
Yellow-Throated Warbler - Look-Look-Look-Come-Look-at-ME — you can hear them singing on territory near the picnic area at Leesylvania State Park