New World Sparrows

Today’s bird family is Passerellidae , which contains the New World Sparrows. The family Passerellidae contains 132 species in 30 generas. Of those, 43 species can be found in North America. Each genera can either contain a single species, like Amphispiza, which just contains the Black-throated Sparrow all the way up to Atlapetes, which contains 33 species. Not all members of this family have the word sparrow in their name though, some are called Juncos, Towhees, Bunting or Finch.

While both New World, Passerellidae, and Old World Sparrows, Passeridae are called sparrows, the New World Sparrows are actually more closely related to Old World Buntings than the Old World Sparrows. These New World Sparrows even used to be classified with buntings in the family Emberizidae until 2017 when they were split from that group. When we talk about New Versus Old world, what that is talking about is where they are from. And this goes for all birds. The New World includes the Americas, North, South and Central. Old world refers to Asia, Africa and Europe. Like many species, they got their name from when European colonizers came over to the new world, our sparrows looked and acted similar to their sparrows, thus were given the same name. Two species I also like to use as another example of this recycling of names is our American Robin and the European Robin, yes, they look very similar, but are completely unrelated. With the American Robin being a thrush and the European Robin being a flycatcher. 

Overall, this group of birds are on the smaller side, with large heads, short necks, long tails and have conical bills. Those in the north are the ones that tend to be more brown, streaked and are the ones with face-patterns, as you go further south, the species tend to become less streaked and start having more blacks, grays, olives and reddish-browns in their plumage. Many in this family also have distinctive face or head patterns, many times you are even able to easily identify the species just by these patterns. Some are boldly patterned with contrasting colors, like the white-crowned sparrow, some are faint, like the field sparrow, or not present at all like in the Towhees or Juncos. New World sparrows also have 10 primary feathers, with the 10th one being usually hidden by other feathers. Not all New World Sparrows have that typical sparrow shape though, species in the neotropics such as Central and South America, can be much larger with brighter colors than North American sparrows. While generally males and females look the same in this family, not all follow this rule. For example, the Eastern Towhee and Lark bunting display sexual dimorphism, meaning the males and females can be distinguished by their plumage. Most species in this family also have dark eyes, some like the Eastern Towhee can have red eyes, yellow like the Volcano Junco or silvery like the Short-billed Chlorospingus.

The smallest member of this family is the LeConte’s Sparrow (Ammospiza leconteii). This little sparrow can be found through parts of Canada down through the central part of North America in marshy habitats. They measure about 4.7 inches long and weigh .4-.6 oz. On the other side of the spectrum, seeming to be the largest member of this family is either the California Towhee or the Canyon Towhee, both measure up to about 9.8 inches long. Though, overall their average length is 6 inches.

As said earlier, these New world Sparrows can be found throughout North, South and central America. Just as diverse this group is, including its impressive range, they also inhabit a wide range of different habitat types. From grasslands, deserts, swamps and marshes, to forests, both temperate and tropical. Some species are more generalists, being found in a wider range of habitats, like the Song Sparrow, who is not too picky on the area they call home. But most species are more habitat specialists. The Saltwarsh sparrow, as its name suggests, is only found in salt marshes along the eastern coast. In the desert regions, you can find species such as the Black-throated Sparrow, Rufous-winged Sparrow or the Canyon Towhee. In fields of grasslands, you will see and hear species such as Field Sparrows, Savannah Sparrows and Grasshopper Sparrows. The tropics forests contain species such as the Chlorospingus. While most species tend to stay in one area year-round, they may migrate slightly south in the winter months.

New World Sparrows tend to feed on a variety of different insects, fruits and seeds. The percentage of each varies between species and time of the year. During the non-breeding season, many species have seeds as a higher percentage of their diet. Some species that like along coastal areas have been known to eat mollusks and crustaceans. Towhees can often be seen foraging among leaf litter on the ground, raking leaves away in search of food, this style of foraging on the ground is shared by many sparrows. Others may prefer to pick insects and seeds directly off various plants and vegetation.

As a whole, this group of birds are generally monogamous with both the male and female caring for the young and their breeding range as a family extends from the Arctic Tundra, like the White-throated Sparrow all the way south to the southern tip of South America. An open cup style nest is the most common style of nest constructed and generally done so by the female, who also does all the incubation. These nests are generally constructed with plant materials such as grasses and small twigs. Nests are built in shrubs, trees, or on the ground. Some species though, like the Backmans sparrow,  build domed nests. In these nests, these sparrows typically have a clutch of one to seven eggs. Afterwards, these eggs are incubated from anywhere from 12 to 15 days and another 7 to 15 days til they fledge. Both parents will then continue to care for the young for up to another month before they become fully independent. An interesting fact about breeding ranges of sparrows is that the Harris’s sparrow is unique for it is North America’s only songbird that’s breeding range lays exclusively in Canada, leading it to be one of last species in North America to have its nest documented.

Of the 132 species in this family, 18 of them are listed as a conservation concern, with seven near-threatened, four vulnerable, six endangered and one critically endangered. The critically endangered Antioquia Brush-finch is only known from three museum specimens. Two expeditions were conducted, one in 2007 and the other in 2008, unfortunately neither of these quests were successful in refinding the species. Habitat loss seems to be the main threat to many of these threatened sparrow species. Many of these threatened species live in very restricted ranges, such as the Pale-headed Brushfinch who has a range of only about 1 km. Or the Zapata Sparrow which can only be found in three wetlands in Cuba. One of the main threats facing these sparrows, especially those with such a small range, is loss of habitat. Crucial habitat is often converted for agricultural use. And lastly, one in the family is extinct, the Bermuda Towhee, which is only known from fossil remains and a few sightings made in 1610-1611.