Baird's junco (''Junco bairdi'') is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

junco A junco (), genus ''Junco'', is a small North American bird in the New World sparrow family Passerellidae. Junco systematics are still confusing after decades of research, with various authors accepting between three and twelve species. Desp ...

, a group of small, grayish

New World sparrow New World sparrows are a group of mainly New World passerine birds, forming the family Passerellidae. They are seed-eating birds with conical bills, brown or gray in color, and many species have distinctive head patterns. Although they share th ...

s. It is endemic to the forests in the higher elevations of the

Sierra de la Laguna The Sierra de la Laguna is a mountain range at the southern end of the Baja California peninsula in Mexico, and is the southernmost range of the Peninsular Ranges System. It is located in La Paz Municipality, Baja California Sur, La Paz Municipa ...

mountain range of the southern Baja California peninsula in

Baja California Sur Baja California Sur, officially the Free and Sovereign State of Baja California Sur, is a state in Mexico. It is the 31st and last state to be admitted, in 1974. It is also the second least populated Mexican state and the ninth-largest state by ...

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

Taxonomy and systematics

While originally described as a distinct species, it was once considered a subspecies of the

yellow-eyed junco The yellow-eyed junco (''Junco phaeonotus'') is a species of junco, a group of small New World sparrows. Its range is primarily in Mexico, extending into some of the mountains of the southern tips of the U.S. states of Arizona and New Mexico. It ...

(''Junco phaeonotus'') before being recognized as a distinct species again in 2014 by the AOS after further research. Within the genus junco, Baird's junco is the outgroup to all other juncos with the exception of the volcano junco, having diverged from other members of the genus more than 350,000 years ago despite retaining a phenotype similar to other North American juncos.

Etymology

The type specimens of Baird's junco were collected on February 2, 1883, by

Lyman Belding Lyman Belding (June 12, 1829 – November 22, 1917) was a prominent American ornithologist. Biography Lyman Belding was born to Joshua Belding and Rosetta Cooley Belding on June 12, 1829, at West Farms, Massachusetts, but later moved to King ...

at "Laguna, Lower California"

Baja California Baja California, officially the Free and Sovereign State of Baja California, is a state in Mexico. It is the northwesternmost of the 32 federal entities of Mexico. Before becoming a state in 1952, the area was known as the North Territory of B ...

and it was named for

Spencer Fullerton Baird Spencer Fullerton Baird (; February 3, 1823 – August 19, 1887) was an American naturalist, ornithologist, ichthyologist, Herpetology, herpetologist, and museum curator. Baird was the first curator to be named at the Smithsonian Institution. He ...

, an American ornithologist and naturalist, by

Robert Ridgway Robert Ridgway (July 2, 1850 – March 25, 1929) was an American ornithologist specializing in systematics. He was appointed in 1880 by Spencer Fullerton Baird, secretary of the Smithsonian Institution, to be the first full-time curator of birds ...

, the curator of birds at the

United States National Museum The Smithsonian Institution ( ), or simply the Smithsonian, is a group of museums, Education center, education and Research institute, research centers, created by the Federal government of the United States, U.S. government "for the increase a ...

at that time.

Description

Baird's junco is approximately average-sized for a New World sparrow, with males being (on average) larger than females and most individuals being approximately in length with a mass of approximately . Baird's junco have the shortest wings () and the shortest tails () of any member of the genus ''Junco'', something that is likely correlated to their sedentary, non-migratory nature.

Plumage

Baird's juncos are sexually monomorphic, and adult Baird's juncos have gray heads with black lores, buffy brown backs, wings, and flanks, and paler gray or white throats blending into a pale whitish chest, belly, and vent. Some individuals are browner below, with color from the flanks covering more of the undersides. Like other members of the genus junco, the outermost tail feathers are white, giving a distinct white flash when birds fly. Baird's juncos have bright yellow eyes, and dull pinkish to pinkish-horn or yellow-orange bills with a maxilla usually darker than the mandible, giving a bicolored appearance to the bill.

Vocalizations

The vocalizations of Baird's junco are quite distinct, and are significantly different from other populations of "yellow-eyed" juncos in North America. Baird's junco songs are fairly complex, especially for the genus junco, and consist of longer songs with multiple unique phrases and few repeats of phrases within each song.

Distribution and habitat

Baird's junco is restricted to the higher elevations of the Sierra de la Laguna, Baja California Sur, Mexico, where it nests in pine-oak forests. This species is largely restricted to the higher elevations above where appropriate habitat occurs, but non-breeding individuals do wander lower down, with previous sources considering the bird common above in elevation and more contemporary sources noting records as low as in elevation. These low elevational records have been attributed to non-breeding individuals, and no significant pattern of elevational migration has been noted.

References

{{Taxonbar, from=Q31872941 Baird's junco Birds of Mexico Baird's junco Endemic birds of Mexico Taxa named by Robert Ridgway