TELLURIDE – Faced with continuing population declines among the few remaining Gunnison Sage-grouse living in the San Miguel Basin, the Colorado Division of Wildlife will implement a predator control program in the Miramonte Basin in the coming weeks.
Centered on the Dan Noble State Wildlife Area at the west end of San Miguel County and extending to private lands immediately surrounding it, the program will be enacted in partnership with United States Department of Agriculture’s Animal and Plant Health Inspection Service.
Coyotes, foxes and ravens will be the primary targets of the control program, while secondary targets include raccoons, skunks, and possibly bobcats, badgers and ground squirrels, depending on the level of threat they pose to the bird species.
“We will target raccoons and skunks in the area if they’re close to the nesting areas,” said APHIS Grand Junction District Supervisor David Moreno, who will oversee the operation.
“Ravens will be a target species for sure,” he continued. “Ravens are a threat to any ground or tree nesting bird.”
The fate of bobcats and badgers is less certain.
“If their activity is close to a lek [breeding area] or strutting ground then we have to be concerned,” said Moreno, who indicated that his office plans on using active control measures from the start of the program later this month until the early summer when the juvenile birds are able to fly and, therefore, better equipped to avoid predation.
“Up to that point they tend to be more helpless,” he explained.
Although Gunnison Sage-grouse were once found throughout the Southwest, today an estimated 4,000 breeding individuals live in seven populations in isolated areas of southwest Colorado and southeast Utah, or about 10 percent of their historic range.
The core population is located in Colorado’s Gunnison Basin where it numbers about 3,000. Other Colorado satellite populations are found in the San Miguel Basin, Monticello-Dove Creek, Piñon Mesa, Crawford, Cerro Summit-Cimarron-Sims Mesa, and Poncha Pass areas.
The decision comes after nearly a decade of work to protect and improve habitat and conditions for birds in the San Miguel Basin, where CDOW researchers last year counted 25 males on 11 known leks following their annual spring count of the birds. The number represented the fifth straight year of local population declines since 2006. Counts of females are less reliable because they are so well camouflaged.
A total of 123 Gunnison Sage-grouse are now estimated to remain in the San Miguel Basin, with its core population found in the Miramonte Reservoir area. There, researchers counted 14 males last spring, down from 18 in 2009.
In 2007 the agency implemented a juvenile survival and dispersal study that concluded in 2010. It included the Miramonte and Gunnison Basin population segments and the Miramonte results were considered “particularly disturbing,” according to the predator control plan.
“Out of the hens radio collared during the four-year study, no chick survival was observed. In nearly every instance nest or chick predation was to blame,” it stated.
“The Division has avoided predator control from the very start,” said Montrose-based CDOW Wildlife Conservation Biologist Jim Garner, of the decision to implement the two-year predator control program that was recently approved by the Colorado Wildlife Commission and has received support from the local San Miguel Basin Gunnison Sage-grouse Working Group.
Garner said that predator control is not a preferred option simply because its effects are short lived, but that the CDOW is concerned that time is running out for the bird. Last fall the US Fish and Wildlife Service listed it as a warranted for protection under the federal Endangered Species Act, but precluded from listing by higher priority species.
That said, USFWS Western Colorado Field Supervisor Al Pfister confirmed earlier this week that a proposed rule to list the species for ESA protection could be published by the agency within the next 12 to 18 months, if funding and authorization to proceed are received, resulting in the “pretty high likelihood” that the bird will receive federal protection in the next two to three years.
“It’s sort of like a bucket in the ocean,” Garner described predator control, explaining that eliminating one type of predator from the Miramonte area will make it possible for predators from other areas to move in and replace them.
“It’s not a long-term solution, but we have pretty much emptied our toolbox,” he said, explaining that the land protection and habitat work done to date are not having their desired effects quickly enough.
“It takes years to see any response and we’re running out of time,” he said.
“We’re afraid the population is going to be gone.”
Despite the shortfalls of predator control, the CDOW still believes it is worth trying to give the Miramonte Gunnison Sage-grouse a temporary reprieve from as many predators as possible in order to them an opportunity to rebound.
“Their biggest defense is numbers,” Garner said.
In the Miramonte area now, however, it’s not uncommon to see lone hens, or perhaps duos, trying to protect their broods. (Flocks in the healthier Gunnison Basin population typically number 25-30 birds).
“That’s why the predators are having such an impact,” he said. “They just can’t deal with them.”
In fact, “The population is just so low we think we may have reached a threshold where even under normal predation the numbers can just not recover,” he said.
While snow cover remains on the ground, APHIS personnel will eliminate targeted animals through aerial gunning. The spring thaw will bring about the use of different measures including calling and shooting, in which calls of distressed animals such as rabbits or fawns are played in order to lure coyotes near, and various forms of traps.
When coyotes are known to travel through an area but other animals are not, neck snare traps, which are immediately lethal provided an animal is caught by its neck, will be employed.
In instances where other, non-target animals may be mistakenly caught, non-lethal padded leg-hold traps and cage traps will be used. Targeted predators caught in those traps will be quickly and humanely dispatched with a shot to the head, said Moreno.
In conjunction with the elimination of adult coyotes, any spring pups will also be targeted by means of cartridges that release a toxicant composed primarily of carbon monoxide into their dens.
“It’s the most efficacious, efficient and timely way of euthanizing the pups,” said Moreno, noting that the cartridges are approved for use by the US Environmental Protection Agency.
Following the first period of active control the CDOW will monitor the birds throughout the rest of the summer and fall. Then APHIS will step in mid-winter of 2012 to resume active control when coyotes begin pairing up to mate once again.
“We're not that crazy about having to do predator control, but we realize that it’s necessary,” said Leigh Robertson, coordinator of the San Miguel Basin Gunnison Sage-grouse Working Group, where the topic has been under discussion for about a year.
While a number of members of that group, particularly landowners, have proposed predator control for some time, even those most resistant to the idea are lending their grudging support.
“All the eggs are getting eaten and no young are surviving to replace the adults,” she explained.
“Our members realize that at least for a while we might have to do predator control just to give the grouse a chance to come back.”
In an effort to further the successful conservation of the species, the group will hold a special program on Tuesday, Feb. 8 at the US Forest Service office in Norwood, 1150 Forest St., to which the public is invited.
From 3-5 p.m. the Working Group will discuss its 2010 accomplishments and plans for 2011 during its regular meeting. After a dinner break (bring your own or dine out), refreshments will be served at 6 p.m. followed by a presentation from attorney Jim Link concerning conservation easements and estate planning from 6:30-7:30 p.m.
Dan Reinkensmeyer of the USFS will then discuss the possibility of the Gunnison Sage-grouse being listed for federal protection and the impacts such a listing could have to landowners. At 8 p.m. landowners will have an opportunity to learn about a program that helps pay for improvements to Gunnison Sage-grouse habitat.
For more information, contact Leigh Robertson at 970-708-7131 or see www.freewebs.com/sanmiguelsagegrouse.