Las Vegas Sun

March 28, 2024

Going, going, gone?

Scientists this summer have been unable to find a single living Mount Charleston blue butterfly, a rare denizen of isolated habitats in the Spring Mountains west of Las Vegas.

Researchers said the fact that the butterfly has not been seen despite efforts throughout the summer in habitats on both the Kyle Canyon and Lee Canyon sides of Mount Charleston is potentially bad news for the species.

Dennis Murphy, a UNR biology professor, said it could indicate that the animal, suspected to be either a subspecies or possibly a unique relative of California's Shasta blue butterfly, is extinct in the Spring Mountains.

"It's a pretty dramatic outcome," Murphy said. "There are two potential explanations. One is that the butterfly has gone extinct on the mountain - gone from low population numbers to absolutely vanishing.

"The other possibility is that conditions have been pretty extreme. We have had as deep a drought following as wet a year as one could imagine It could be that those eggs did not hatch this year and the eggs are waiting for better circumstances to hatch as caterpillars."

The butterfly is about a half-inch long, and a deep blue or violet color. Adults usually emerge from their cocoons in mid- to late summer. They live for less than a week on the high mountain meadows that are their cool, wet alpine islands, a world apart from the dry, hot desert around the mountains.

Habitat loss and extreme weather over the last two years have probably hurt the population of many Spring Mountain butterfly species, Murphy said.

"I think that we're not going to see the (Mount Charleston blue) butterfly this year," he said, "and there is at least the possibility that we may not see it again."

Bruce Boyd, a researcher working with Murphy, said he has seen the butterfly every year since 1994 - until this year: "This is the first time to our knowledge that this has occurred, that the species did not fly."

Boyd said no formal counts of the Mount Charleston blue have been done . In "periods of peak flight," however, he has seen as many as several hundred in one high-elevation meadow in Lee Canyon. The insect has been found in a dozen or so of the meadows high on the mountain.

Boyd said he could not rule out the possibility that some Mount Charleston blues emerged from caterpillar cocoons and took flight, but his search included the entire eastern slope of the Spring Mountains, including "every known historical location" for the butterfly, throughout the late spring and summer.

Last year, a California conservation group filed a request with the U.S. Fish and Wildlife Service to grant the butterfly emergency protections under the federal Endangered Species Act. The service rejected the emergency petition but began a 90-day review as required by law.

Cynthia Martinez, Fish and Wildlife assistant field supervisor, said the agency's finding of "substantial or not substantial" need for federal protection as an endangered or threatened species has been completed and was not likely to include the latest information from the scientists.

That finding is under internal review and will go to the Fish and Wildlife Service's regional offices in California in mid-September for additional review. Once past that hurdle, it will go to the agency's offices in Washington and finally to a decision entered into the Federal Record in November, Martinez said.

The agency will not release its decision during the review process, she said.

Martinez said her agency was working with the U.S. Forest Service, which oversees most of the mountain, to identify issues affecting the Mount Charleston blue and to develop a management plan for the area.

Karen Harville, a Forest Service biologist, said her agency did not have any formal monitoring efforts targeting the Mount Charleston blue over the summer, when the butterfly usually takes flight. The agency did a survey of other butterfly species on lower elevations on the mountain, and the populations of about a dozen species appeared to be lower than in previous counts.

"It wasn't very good this year," Harville said, adding that the results do not mean a permanent disappearance of any species. The insect larvae, the immature forms of the insect, can remain dormant for years.

Beth Moore, a Forest Service spokeswoman, agreed: "There's nothing alarming or out of the norm."

Boyd acknowledged the butterflies could return next year.

"It could be that the environmental cues that would tell this thing to emerge this year told it instead to not emerge this year," Boyd said. "That is not to say that everything is fine and dandy. The threat to this species is probably greater than we had perceived."

The butterfly researchers did not have access this year to conservation funds generated by the sale of federal land in Clark County. Murphy said he used funds from other, statewide research projects to pay for what he described as modest efforts to count the Mount Charleston blue and other species.

The lack of federal funding for summer research projects sparked concern from some scientists and environmentalists. Clark County and federal agencies work together to approve and fund research and conservation projects under the umbrella of the Clark County Multi-Species Habitat Conservation Plan.

Next year, the habitat funds from the sale of federal lands should provide more research money for the butterflies and other warm-weather species.

Murphy contrasted the Mount Charleston blue's situation to that of Northern Nevada's Sand Mountain blue butterfly, a species that is not directly related to the Clark County insect. Fish and Wildlife has moved to list the Sand Mountain butterfly as endangered.

Murphy, who has been researching the butterfly this summer, said there are perhaps 500,000 to 1 million on a couple of square miles outside Fallon.

The Mount Charleston blue is in a much tougher spot, he said: "(It) is unequivocally the state's most at-risk invertebrate at this point, and may be the state's most at-risk species."

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