PORTLAND, Ore. (KOIN) — Streaked horned larks were once a prevalent bird species in Oregon and Washington, but the Washington Department of Fish and Wildlife has reported that they have become rare due to habitat loss.

Now, the Center for Biological Diversity and the Audubon Society of Portland are suing the U.S. Fish and Wildlife Service for what they believe is the Service’s role in the endangerment of the species.

According to the two organizations, the U.S. Fish and Wildlife Service first listed the lark as “threatened” in 2013 — despite lark experts’ calls to list them as “endangered.” Again in April 2022, the Service announced that the larks remained listed as “threatened” under the Endangered Species Act.

“Ongoing habitat loss is negatively affecting streaked horned larks, but they have adapted to use some managed landscapes,” the Service’s Pacific Regional Director Robyn Thorson said in a release. “We revised the 4(d) rule to promote future conservation and recovery by encouraging activities that support the creation and maintenance of habitat for this subspecies across its range.”

The Center for Biological Diversity and the Portland Audubon have challenged the listing, per their lawsuit that was filed on Tuesday, Jan. 31. The lawsuit states that the larks’ already declining population is now facing extinction due to factors including climate change, invasive species and severe weather events.

“The weight of scientific evidence clearly points to a bird that should be listed as endangered under the Endangered Species Act,” Joe Liebezeit, Portland Audubon’s staff scientist and avian conservation manager, said. “We need to give this bird a fighting chance to recover from extinction’s doorstep.”

The Portland Audubon estimates that between 1,170 and 1,610 larks are left in Washington and Oregon. It also said that Taylor’s checkerspot butterflies, Willamette daisies and Kincaid’s lupines are among the species with declining populations.

KOIN 6 reached out to the U.S. Fish and Wildlife Service for comment.