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Birds like white-crowned sparrows are originally evolved from Theropods. Because scientists discovered that Archaeopteryx has unique features that are somewhat related to Theropods making the Theropods the ancestor of birds as well.

The origin of birds. Evolution.berkeley.edu. (2021). Retrieved 21 September 2021, from https://evolution.berkeley.edu/evolibrary/article/evograms_06.

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The origin of birds

The discovery that birds evolved from small carnivorous dinosaurs of the Late Jurassic was made possible by recently discovered fossils from China, South America, and other countries, as well as by looking at old museum specimens from new perspectives and with new methods. The hunt for the ancestors of living birds began with a specimen of Archaeopteryx, the first known bird, discovered in the early 1860s. Like birds, it had feathers along its arms and tail, but unlike living birds, it also had teeth and a long bony tail. Furthermore, many of the bones in Archaeopteryx's hands, shoulder girdles, pelvis, and feet were distinct, not fused and reduced as they are in living birds. Based on these characteristics, Archaeopteryx was recognized as an intermediate between birds and reptiles; but which reptiles?

In the 1970s, paleontologists noticed that Archaeopteryx shared unique features with small carnivorous dinosaurs called theropods. All the dinosaur groups on this evogram, except the ornithischian dinosaurs, are theropods. Based on their shared features, scientists reasoned that perhaps the theropods were the ancestors of birds. When paleontologists built evolutionary trees to study the question, they were even more convinced. The birds are simply a twig on the dinosaurs' branch of the tree of life.

In theropods even more closely related to birds, like the oviraptorosaurs, we find several new types of feathers. One is branched and downy, as pictured below. Others have evolved a central stalk, with unstructured branches coming off it and its base. Still others (like the dromaeosaurids and Archaeopteryx) have a vane-like structure in which the barbs are well-organized and locked together by barbules. This is identical to the feather structure of living birds.

Another line of evidence comes from changes in the digits of the dinosaurs leading to birds. The first theropod dinosaurs had hands with small fifth and fourth digits and a long second digit. As the evogram shows, in the theropod lineage that would eventually lead to birds, the fifth digit (e.g., as seen in Coelophysoids) and then the fourth (e.g., as seen in Allosaurids) were completely lost. The wrist bones underlying the first and second digits consolidated and took on a semicircular form that allowed the hand to rotate sideways against the forearm. This eventually allowed birds' wing joints to move in a way that creates thrust for flight.

The functions of feathers as they evolved have long been debated. As we have seen, the first, simplest, hair-like feathers obviously served an insulatory function. But in later theropods, such as some oviraptorosaurs, the feathers on the arms and hands are long, even though the forelimbs themselves are short. What did these animals do with long feathers on short arms? One suggestion comes from some remarkable fossils of oviraptorosaurs preserved in the Cretaceous sediments of the Gobi Desert. The skeleton of the animal is hunched up on a nest of eggs, like a brooding chicken. The hands are spread out over the eggs as if to shelter them. So perhaps these feathers served the function of warming the eggs and shielding them from harm.
Birds after Archaeopteryx continued evolving in some of the same directions as their theropod ancestors. Many of their bones were reduced and fused, which may have helped increase the efficiency of flight. Similarly, the bone walls became even thinner, and the feathers became longer and their vanes asymmetrical, probably also improving flight. The bony tail was reduced to a stump, and a spray of feathers at the tail eventually took on the function of improving stability and maneuverability. The wishbone, which was present in non-bird dinosaurs, became stronger and more elaborate, and the bones of the shoulder girdle evolved to connect to the breastbone, anchoring the flight apparatus of the forelimb. The breastbone itself became larger, and evolved a central keel along the midline of the breast which served to anchor the flight muscles. The arms evolved to be longer than the legs, as the main form of locomotion switched from running to flight, and teeth were lost repeatedly in various lineages of early birds. The ancestor of all living birds lived sometime in the Late Cretaceous, and in the 65 million years since the extinction of the rest of the dinosaurs, this ancestral lineage diversified into the major groups of birds alive today.

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The origin of birds The discovery that birds evolved from small carnivorous dinosaurs of the Late Jurassic was made possible by recently discovered fossils from China, South America, and other countries, as well as by looking at old museum specimens from new perspectives and with new methods.

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Archaeopteryx lithographica (150.8 million years - 125.45 million years)

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Archaeopteryx lithographica (150.8 million years - 125.45 million years)

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Archaeopteryx lithographica was discovered in 1861 by the paleontologist Christian Erick Hermann von Meyer. It was considered as the first bird in the world, it was believes that this species are belong reptiles, but it changed to Aves because it has a feature of a bird.  It is believed that it lived until the late cretaceous era 65 million years after extinction.

Ji, Q., & Ji, S. (2001). On the Discovery of the earliest fossil bird in China (Sinosauropteryx gen. nov.) and the origin of birds. Chinese Geological Museum, Beijing.

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An ornithologist who described the features and developed the first classification system of all the then-known birds in the world. He and published the book of "Ornithologiae Libri Tres" with the help of his friend, John Ray.

Francis Willughby - Wikipedia. En.wikipedia.org. (2021). Retrieved 21 September 2021, from https://en.wikipedia.org/wiki/Francis_Willughby#Subjects_of_his_studies.

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He modified the Classification system of Francis Willughby into Taxonomy Classification system. He's also the one who gave scientific name the Passeriformes to sparrows, which are one of the first among animals to be given a scientific name.

Carl Linnaeus - Wikipedia. En.wikipedia.org. Retrieved 21 September 2021, from https://en.wikipedia.org/wiki/Carl_Linnaeus.

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A French polymath who introduced the family Passeridae as Passernia.
According to the Handbook of the Birds of the World, there are three main groups of sparrows and those sparrows are the true sparrows (Passer), the snowfinches (Montifringilla), and the rock sparrows (Petronia). The sparrow-weavers (Plocepasser) and several other African taxa (Ploceidae) that are morphologically similar to Passer are also included in some classifications.

Old World sparrow - Wikipedia. En.wikipedia.org. Retrieved 21 September 2021, from https://en.wikipedia.org/wiki/Old_World_sparrow.

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It is a group of sparrows that belongs to the Passer, one of the main group of sparrows. These sparrows are considered as the original sparrows which is why they're also called the True Sparrows. These sparrows are small, plump brown-gray birds with short tails and small but powerful beaks.

Old World sparrow - Wikipedia. En.wikipedia.org. Retrieved 21 September 2021, from https://en.wikipedia.org/wiki/Old_World_sparrow.

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One of the types of sparrow is the White-Crowned Sparrow.
J.R. Forster is a German naturalist and first person who studied and described the White crowned sparrows as “elegant little species”.

Chilton, G., Baker, M., Barrentine, C., & Cunningham, M. (2021). White-crowned Sparrow (Zonotrichia leucophrys). Birdsoftheworld.org. Retrieved 19 September 2021, from https://birdsoftheworld.org/bow/species/whcspa/cur/introduction.

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White-crowned Sparrows can frequently see in winter over much of North America to grace our gardens. Its dashing look combined with crispy gray breast and black-and-white head has made them as one of the surest sparrow identification in North America. As spring approaches, listen out for this bird’s thin, sweet whistle.

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An american ornithologist who studied the different song structure and variation of the bird.

Barbara Blanchard DeWolfe – Museum of Vertebrate Zoology. Mvz.berkeley.edu. (2021). Retrieved 19 September 2021, from https://mvz.berkeley.edu/announcement/barbara-blanchard-dewolfe/.

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From his research, he found that the songs of male white-crowned sparrows are normally acquired by learning from adults. Male white-crowned sparrows raised in individual or group isolation developed abnormal songs. It was found that the crucial period of exposure to normal song is from 10-50 days for normal song development.

Marler, P. (1970). A comparative approach to vocal learning: Song development in white-crowned sparrows. Journal Of Comparative And Physiological Psychology, 71(2, Pt.2), 1-25. https://doi.org/10.1037/h0029144

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Song Dialects and Genetic Differences in white-crowned sparrows

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Song Dialects and Genetic Differences in white-crowned sparrows

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The research found that dialect populations are contagious; those male white-crowned sparrows who live in common geographic areas exhibit common dialects.

Baker, M. (1974). SONG DIALECTS AND GENETIC DIFFERENCES IN WHITE‐CROWNED SPARROWS (ZONOTRICHIA LEUCOPHRYS). Evolution, 29(2), 226-241. https://doi.org/10.1111/j.1558-5646.1975.tb00203.x

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He conducted dozens of research on different bird species; however, he was most recognized for his study on the habits of white-crowned sparrows. The contributions of Dr. Luis became fundamental to understanding bird communication and vocalization. He described the sparrows as “the white rat of ornithology.”

Luis F. Baptista; Ornithologist Mastered the Dialects of Birds. Los Angeles Times. (2021). Retrieved 19 September 2021, from https://www.latimes.com/archives/la-xpm-2000-jun-15-me-41262-story.html.

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The first sparrow that declared extinct in 1990.

Dusky seaside sparrow - Wikipedia. En.wikipedia.org. Retrieved 21 September 2021, from https://en.wikipedia.org/wiki/Dusky_seaside_sparrow.

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Studied the preference of different subspecies, either male or female, of white crowned sparrow in terms of their songs for mating purposes.

Nelson, D. (2000). A preference for own-subspecies' song guides vocal learning in a song bird. Proceedings Of The National Academy Of Sciences, 97(24), 13348-13353. https://doi.org/10.1073/pnas.240457797

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The condition of nestling House Sparrows Passer domesticus in relation to diet composition and the total amount of food consumed.
Alena KLvanova states that breeding and nesting is affected by the scarcity of food and nutrients that will soonly affect the growth and development of the population.

Klvaňová, A., Lusková, M., Hořák, D., & Exnerová, A. (2012). The condition of nestling House SparrowsPasser domesticusin relation to diet composition and the total amount of food consumed. Bird Study, 59(1), 58-66. https://doi.org/10.1080/00063657.2011.643291

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This sparrow was considered as the biggest sparrow in the world.

Harris's sparrow - Wikipedia. En.wikipedia.org. Retrieved 21 September 2021, from https://en.wikipedia.org/wiki/Harris%27s_sparrow.

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The researchers discovered that young birds like white-crowned sparrows may be more sensitive to and focused on noises from their own species. In comparison to other species, there sparrows chirps more in response to the replay of white-crowned songs, showing that it is a more pronounced stimulus to them and hence the one that catches their attention, even at this early stage.

Baker, M. (1983). The behavioral response of female Nuttall's White-crowned Sparrows to male song of natal and alien dialects. Behavioral Ecology And Sociobiology, 12(4), 309-315. https://doi.org/10.1007/bf00302898

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Migratory Sleeplessness in White-Crowned Sparrow 

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Migratory Sleeplessness in White-Crowned Sparrow 

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An article that explains the travel and the hours of sleep of white crowned sparrows to different places during seasonal migration and how they maintain their neurological focus throughout the travel.

Rattenborg NC, Mandt BH, Obermeyer WH, Winsauer PJ, Huber R, Wikelski M, et al. (2004) Migratory Sleeplessness in the White-Crowned Sparrow (Zonotrichia leucophrys gambelii). PLoS Biol 2(7): e212. doi:10.1371/journal.pbio.0020212

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Researched about displacement of white crowned sparrows through migration and how far they can travel while migrating.

Åkesson, S., Morin, J., Muheim, R., & Ottosson, U. (2005). Dramatic Orientation Shift of White-Crowned Sparrows Displaced across Longitudes in the High Arctic. Current Biology, 15(17), 1591-1597. https://doi.org/10.1016/j.cub.2005.07.027

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She discovered that white-crowned sparrows are close-ended learners where they learn a song a few months after hatching. The phase is called sensorimotor phase.

Wada, H. (2010). The Development of Birdsong | Learn Science at Scitable. Nature.com. Retrieved 19 September 2021, from https://www.nature.com/scitable/knowledge/library/the-development-of-birdsong-16133266/.

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The evolution of the dialects of white-crowned sparrows in line with the environmental change and the impact of the increasingly noisy city on bird songs. Biologist David Luther and his colleagues have documented that these birds have shifted to a dialect more audible above the urban din but still, many birds vanish from areas as it affects the growth of young birds because they rely most heavily on sound.

Todd, K. (2016). Bay Nature Magazine: Sparrows Lose Their Language With Urban Noise. Bay Nature. Retrieved 19 September 2021, from https://baynature.org/article/the-language-of-sparrows/.

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When the pandemic quieted San Francisco, these birds could hear each other sing.

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When the pandemic quieted San Francisco, these birds could hear each other sing.

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According to the behavioral ecologist Liz Derryberry's experiment, the urban birds' calls became higher in quality and each is packed with more information during the pandemic, making mating easier for the birds. They also added that noises from oil and gas drilling, basically urban noises, can lower bird fertility.

Arnold, C. (2020). When the pandemic quieted San Francisco, these birds could hear each other sing. Animals. Retrieved 19 September 2021, from https://www.nationalgeographic.com/animals/article/pandemic-san-francisco-birds-song-improved.

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House Sparrows are usually noisy sparrows that flutter down from eaves and fencerows to hop and peck at crumbs or birdseed. You can normally see them flying in and out of nest holes, behind traffic lights, or hanging around parking lots foraging crumbs and insects off car grills.

House Sparrow Identification, All About Birds, Cornell Lab of Ornithology. Allaboutbirds.org. Retrieved 21 September 2021, from https://www.allaboutbirds.org/guide/House_Sparrow/id.

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This species is a very common and close relative of the House Sparrow. Slightly smaller than House Sparrow with an entirely rufous cap, black and white cheek, and limited black in the throat. Males and females are similar. You can see them flying around flocks, oftentimes in more natural areas.

Eurasian Tree Sparrow - eBird. Ebird.org. Retrieved 21 September 2021, from https://ebird.org/species/eutspa.

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Lark Sparrow has its unique black, white, and rufous face pattern. They are large and boldly patterned sparrows. Favors open areas when breeding and often forms flocks in brushy areas in winter. In flight, notice a long tail with broad white corners.

Lark Sparrow - eBird. Ebird.org. Retrieved 21 September 2021, from https://ebird.org/species/larspa.

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Song "Dialects" in Three Populations of White-Crowned Sparrows.  

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Song "Dialects" in Three Populations of White-Crowned Sparrows.  

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Song patterns of three White-crowned Sparrow populations, two close together and one far apart, demonstrated an exceptional level of homogeneity in such characteristics within each population. In one case, the breeding patterns remained consistent over two breeding seasons. There were also obvious and consistent variances between the three populations' singing patterns, with the biggest divergence occurring between those separated by the greatest distance. This is one of the prominent examples of “dialects” in bird song.

Marler, P., & Tamura, M. (1962). Song "Dialects" in Three Populations of White-Crowned Sparrows. The Condor, 64(5), 368-377. https://doi.org/10.2307/1365545

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The functional significance of song sharing in the White-crowned Sparrow

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The functional significance of song sharing in the White-crowned Sparrow

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Different theories have been proposed to explain the adaptive value of learning a dialect of a white-crowned sparrows. The assortative mating theory claims that birds learn dialects in their natal area throughout a brief sensitive phase. Another theory, the social adaptation theory, suggests that birds learn dialects in places where they have resided after being dispersed from their natal/birthplace. The social adaptation idea is supported by the majority of evidence.

Baptista, L. (1985). The functional significance of song sharing in the White-crowned Sparrow. Canadian Journal Of Zoology, 63(8), 1741-1752. https://doi.org/10.1139/z85-263

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Range wide and local barriers of White crowned sparrow wherein the experiment suggests that there are dialects coming from each bird from different places through migration.
It is also believed that songbirds change in tune in urban places; territorial experiment where white crowned sparrows change their song to be able to adapt to loud surroundings. In addition, they are territorial when it comes to their songs.

Welke, C. (2012). RANGEWIDE AND LOCAL BARRIERS TO GENE FLOW IN WHITE- CROWNED SPARROWS (ZONOTRICHIA LEUCOPHRYS) (Master of Science). University of Lethbridge.
David A. Luther, Elizabeth P. Derryberry. Birdsongs keep pace with city life: changes in song over time in an urban songbird affects communication. Animal Behaviour, 2012; 83 (4): 1059 DOI: 10.1016/j.anbehav.2012.01.034