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Worthen's Sparrow

Spizella wortheni

Length: 5 inches Wingspan: 7.5 inches Seasonality: Non-resident in South Dakota
ID Keys: Grey head with rusty crown, white eye-ring, pinkish bill

Worthen's Sparrow - Spizella wortheniThe Worthen's Sparrow was first described by a bird found near Silver City, New Mexico in 1884.  Since that time, it has never again been found in the United States.  The Worthen's Sparrow is now one of the rarest birds in the world, with a tiny range in northeastern Mexico that is no more than 25 square kilometers.  Population estimates vary but there are likely no more than 500 individual birds left, at best, with most estimates putting the total population as less than 150.  They have been recorded as occurring in eight different Mexican states, but their range has shrunk to the point that they are only found in a handful of locations in southeastern Coahuila and western Nuevo Leon.  Habitat loss has been implicated as the primary cause of the species decline.  Conversion of grassland to agriculture, and heavy grazing are primary causes of habitat loss and disturbance at nesting sites.

Habitat: Habitat requirements still are not totally understood.  They are found in arid grasslands with scattered shrubs.  A clue to preferred habitats comes from a location in Caohuila, where a fence divides different land management areas.  The birds strongly prefer the area managed as a natural pasture, with taller grasses and scattered shrubs, as opposed to the overgrazed side with very low grasses.  Overall, breeding has primarily been noted in grasslands with scattered mesquite, juniper, and/or yucca.

Diet: Feeds heavily on seeds, also likely feeds on insects and spiders.

Behavior: Gregarious after the breeding season, forming into flocks that typically reside near permanent water bodies.

Nesting: Poorly understood. Recorded nests have had 3 to 5 eggs, with nests placed low in bushes.

Song: The song is a vaguely musical trilling of a few seconds.

Migration: Considered a permanent resident.  However, birds do form into flocks outside of the breeding season and typically move to areas with adequate foraging opportunities, and a permanent water source nearby.

Interactive eBird map: Click here to access an interactive eBird map of Worthen's Sparrow sightings

Similar Species: Most similar in appearance to the Field Sparrow.

Conservation Status: Populations of Worthen's Sparrows are now only found in 3 distinct sites, all very close to each other.  The total range of the bird has continually declined, as has overall populations.  The IUCN lists the Worthen's Sparrow as "Endangered".   They are considered "regionally extinct" in the United States, as well as in some states in Mexico where they were formerly found.

Further Information: 1) BirdLife International - Worthen's Sparrow

2) Cornell's Neotropical Birds - Worthen's Sparrow

3) Handbook of the Birds of the World - Worthen's Sparrow

Photo Information: Photo by Amy McAndrews - Photo licensed under Creative Commons Attribution NonCommercial NoDerivs 2.0 Generic License


Click below for a higher-resolution map
Worthen's Sparrow - Range Map
South Dakota Status: Non-resident in South Dakota

Additional Worthen's Sparrow Photos (coming soon!!)