Which of the following is an example of a threatened species?

The California condor is an example of a threatened species primarily because it has faced significant population declines due to habitat destruction, lead poisoning, and other human-related factors. In the 1980s, the species was on the brink of extinction, with only a few individuals remaining in the wild, prompting conservation efforts that included a captive breeding program. Today, while the population has increased due to these conservation measures, the California condor is still classified as threatened due to its limited population size and ongoing risks to its habitat.

In contrast, while the gray wolf and American bison have also faced threats in the past, their populations have recovered sufficiently in many areas, leading to their reclassification in some regions. The common sparrow, being a widespread species, is not considered threatened, showing strong resilience and adaptability in various habitats. Therefore, the California condor stands out among the options presented as a species that requires continued conservation attention.