- Habitat destruction
- Livestock grazing
- Nest predation
Worthen’s Sparrow is a Mexican endemic passerine bird that is named after the American naturalist Charles K. Worthen. Its native habitat only consists of a 25 square kilometre range of open grasslands and arid shrubbery area within the north-eastern part of Mexico and it is not considered a migratory bird.
Population decline of the Worthen’s Sparrow species stems from habitat conversion for agriculture lands. Increase of livestock grazing and application of chemicals within the surrounding areas either reduce the quality of the habitat or cause significant disturbance to nesting birds. Worthen’s Sparrow is also prone to being attacked or eaten by predators including other bird species, coyotes, and snakes.