The Blue-winged Warbler has both two different calls and two different songs. One call sounds like “tzipp,” while the other sounds like “zzrrttt.” The “tzipp,” call is used as an alarming sound, and is usually used when the Blue-winged Warbler is engaged in a fight. Females use this call early in the season while they are nest building or to promote pair formation, and to inform males of female’s location. This call is also rarely used after nest-building. The other call, sounds like a begging call of a young fledgling, and females use it when first arriving at a new territory. (Axelson).

The two songs are known as Song I, which has both type A and B, and Song II. Both songs sound like a high-pitched noise and are almost insect-like in their noise. Song I is known as the territorial song, and gives off a “bee buzzzzz” noise. There are two different kinds of song I (Ia and Ib); the only difference being that song 1b has a downward slur of bee phrase, which makes the buzz sound higher pitched. Territorial songs are broken down into two to three phrases or components with the first phrase (component A) normally consisting of continuous, and non-pulsating notes that cannot be heard by the human ear until slowed down from 200-240 Hz to one-sixteenth of that. The second phrase (component B) consists of pulsating syllables that are delivered at about 40-50 Hz. The last phrase (component C) consists of a continuous buzzy vibration. Normally males only have one Song Type I that varies in aspects like central frequency, and modulation rate. Song I is used as a recognition signal for mate selection, and days of courtship are begun with song type I. Males sing song type 1 almost exclusively when arriving at a new territory, and in fact, some blue wing males sing golden-wing rather than blue-wing type 1 song.

Song II on the other hand is known as the nesting song. It sounds like a trill buzz, and is used on territorial boundaries when interacting with other males. Song Type II never consist so component B, sometimes consists of component A and C, but always consists of component D. These components are of both low intensity and high intensity buzz vibration. Males primarily sing Song Type I usually beginning 15 minutes before sunrise. They continue to sing Song Type I throughout the date at a rate of 4-6 songs per minute. The only time males sing Song Type II is when they are interacting with other males.

Even though there are two separate songs, neither has an exact concrete use. For example, even though song type I is known as the territorial song, it’s also used for mate attraction. And even though song type II is known as the nesting song, it can also be used in close encounters with other males when defending one’s territory and not just for mateship. A sonogram of both song type I and song type II can be observed below (Frank, Canterbury, and Confer).

To hear the different song types you can click on the link below, and not only hear the song but also see its corresponding sonogram as it plays.

https://birdsna.org/Species-Account/bna/species/buwwar/multimedia/audio

“Song” represent song I, and “Alternate song” represents song II.

Dialect

The Blue-winged Warbler does have a dialect. Although there are two patterns of Song type I used in Long Island, NY only song type Ia is commonly sung in Michigan. When studying the Blue-winged Warblers dialect Kroodsma did not observe any differences between the dialects used in the NE and the midwest. Depending upon the region there may be a different accented ending song. Modulation rates of buzz vary among regions. For example, in Michigan the buzz is preceded by a high pitched slur instead of a brief burst of song type Ia (Frank, Canterbury, and Confer).

It’s been found that there are more dialects of song type II than song type I. During a playback experiment it was observed that males have a higher and stronger response to local than to foreign songs. Song type II varies from western Massachusetts to eastern NY in the USA. Although males differentiate with song type II, they do not distinguish a difference between local and foreign song type I. One can observe the small variance in dialect between regions in the above picture of the sonograms of song type I and II from birds singing in different geographic regions (Kroodsma, Meservey, Whitlock).

If you care curious about how the song II sounds differently depending on the region, you can access the website below and click on different geographic regions and then hear the corresponding song sung in those locations.

http://www.xeno-canto.org/species/Vermivora-cyanoptera?pg=2

 Song Behavior

Male Blue-Winged Warbler Singing:

http://nancybirdphotography.com/photographing-a-wave-of-migrating-birds/

Young male Blue-winged Warblers learn their songs from their fathers often while being feed. According to Don Kroodsma’s studies where he hand reared young male Warblers and tutored them with Common Yellowthroat song, young male Warblers have the ability to learn song (Kroodsma, Meservey and Pickert). Often male birds are unable to develop normal song without social interaction, suggesting that social interaction plays a crucial part in the Blue-winged Warblers ability to produce song. These experiments suggest that song form and function are learned and adjustable (Frank, Canterbury, and Confer).

 Possible Future Research

Golden Winged-Warbler:

http://wildlife.org/blue-winged-golden-winged-warblers-not-all-that-different/

Blue-winged Warblers (Vermivora cyanoptera) and Golden-winged Warblers (Vermivora chrysoptera) are often considered different species, however, new research suggests that this two birds could in fact be apart of the same species. Based on research from the Cornell Lab of Ornithology Golden-winged Warblers and Blue-winged Warblers are 99.7 percent alike. These birds are normally categorized as different species because of their distinct appearance, different songs, and different places of residence. Researchers Taylor and Toews found in their analysis of the genomes of the two species that the .03 percent of difference comes from a gene controlling the color of the bird’s throat. Golden-winged Warblers have a recessive Mendelian trait for their black colored throat. Another gene that differed most likely controls the body color of these two types of birds; Blue-winged Warblers have a recessive trait for their yellow body. According to the Cornell Lab, these difference are similar to the difference in a person with freckles and one without (Axelson).

In Canada’s species at Risk Act, Golden-winged Warblers are listed as endangered, however, in the United States these species are not considered federally protected (Kobilinsky). This discrepancy in whether or not the Golden-winged Warblers should be protected is due to their crossbreeding with Blue-winged Warblers. Since there is no consensus on whether or not these two birds are of different species people are having a hard time determining whether or not Golden-winged Warblers should be considered threatened.

In order to determine why Blue-winged Warblers are overtaking Golden-winged Warblers we could conduct multiple experiments to see whether or not Blue-winged Warblers are in fact the superior species. If Blue-winged Warblers are the superior species than they will overthrow Golden-winged Warblers. Based off of our hypothesis we’ve predicted either sexual selectional, ecological superiority, or genetic introgression may be the causation of the Golden-winged warblers being pushed out by the Blue-winged Warblers (Frank, Canterbury, and Confer). An experiment testing sexual selection would be to present a female Golden-winged Warbler with a male Blue-winged Warbler and a male Golden-winged Warbler and observe who she chooses to mate with. We would also perform this test on a Golden-winged female. If both females choose the male Blue-winged Warbler than this proves that Blue-winged Warblers are superior to Golden-winged Warblers. To test for ecological superiority we would observe both a male blue and golden winged warbler and see which one better survives in their environment. We would see which species better survives in their environment by comparing the number of mates they have and the lifespan of each bird. Depending upon our results we would be able to confirm or cast out the prediction of ecological introgression. To test for genetic introgression we would crossbreed crossbreed a Golden-winged Warbler and Blue-winged Warbler and see if their offspring flourish more than the individual parents did. If the offspring is better suited for its environment than genetic introgression is a causation of the Blue-winged Warblers overtaking the Golden-winged Warblers.

References:

Gill, Frank B., Ronald A. Canterbury and John L. Confer. 2001. Blue-winged Warbler

(Vermivora cyanoptera), version 2.0. In The Birds of North America (P. G. Rodewald,

editor). Cornell Lab of Ornithology, Ithaca, New York,

USA.https://doi.org/10.2173/bna.58

Axelson, Gustave. Blue-winged Warbler. (n.d.). The Cornell Lab of Ornithology All About

Birds. Retrieved November 12, 2017, from

https://www.allaboutbirds.org/guide/Blue-winged_Warbler/id#

Axelson, Gustave. 2016. Golden-winged and blue-winged warblers are 99.97 percent alike

genetically. The Cornell Lab of Ornithology All About Birds. Summer

2016.https://www.allaboutbirds.org/mixed-wing-warblers-golden-wings-and-blue-wings-

are-99-97-percent-alike-genetically/

Kobilinsky, Dana. 2016. Blue-winged, golden-winged warblers not all that different. The

Wildlife Society. http://wildlife.org/blue-winged-golden-winged-warblers-not-all-

that-different/

Kroodsma, D., W. Roger Meservey, & Roberta Pickert. (1983). Vocal Learning in the

Parulinae. The Wilson Bulletin, 95(1), 138-140. Retrieved from

            http://www.jstor.org/stable/4161725

Kroodsma, D., W. Roger Meservey, Alison L. Whitlock, & W. Matthew VanderHaegen.

(1984).

Blue-Winged Warblers (Vermivora pinus) “Recognize” Dialects in Type II but Not

Type I Songs. Behavioral Ecology and Sociobiology, 15(2), 127-131. Retrieved from

http://www.jstor.org/stable/4599708