Technology solves wildlife mysteries
The night was as dark as the eyeholes of a skull when video surveillance cameras on the Golden Gate Bridge captured the images of a coyote on the walkway. The coyote was trotting from the Marin Headlands across the bridge and into San Francisco.
That was 15 years ago, the first photos that verified how some coyotes reached The City.
In the time since, cams positioned for surveillance and security, both in cities and in the wild along game trails, have captured some electrifying wildlife moments in California.
In the past few months, photos and videos from cams have verified mountain lions in San Francisco and Los Angeles, and wolf pups in a pack west of Eagle Lake in remote Lassen County.
Trail cams, GPS collars and DNA taken from scat show how technology can provide glimpses into a largely secret world where people are otherwise denied entry.
For unique and provocative wildlife species, the technology is helping to solve many mysteries.
Wolves
With GPS collars and trail cams, the Department of Fish and Wildlife was able to verify last year that a female wolf and her mate produced three pups. The pack is living in a range east of Lake Almanor in northern Plumas County and west of Eagle Lake in Lassen County, according to GPS data. DNA from scat shows the male wolf is from the Rogue Pack out of Oregon, the same genetics as OR-7, the famous first wolf the DFW collared. About 10 years ago, a Chronicle story reported that a few residents said they were seeing wolves in Lassen and Modoc counties. It wasn’t until 2011 when trail cams captured OR-7 that DFW confirmed the sightings. This is now the protocol. Earlier this year, for instance, there were multiple sightings of wolves on the flank of Mount Hood, east of Portland. It became news last week when two wolves in this area were photographed on trail cams for the first time.
Wolverine
In 2008, a trail cam in the central Sierra Nevada captured the first image of a wolverine in California in 86 years. Wildlife biologists then placed bait on a tree, adjacent to the trail cam, to lure the wolverine back. DNA from scat traced the wolverine to the Sawtooth Range in Idaho. The remaining mystery is that nobody knows how the wolverine reached California. This wolverine is now believed to be reaching the later stages of its life, and no juveniles or other wolverines have been verified.
Mountain lions
In early November, nobody would have believed a mountain lion was roaming in San Francisco’s Sea Cliff area, but then a security camera captured video evidence of its presence. The lion then showed up 5 miles away in Diamond Heights, where a wildlife officer from DFW darted it with a tranquilizer gun. The lion was transplanted to Peninsula wildlands. Years ago, mountain lion sightings in California were rare. Now they are fairly common, and in one region alone, in the Santa Cruz Mountains north to the Skyline region, scientists have collared more than 40 lions with GPS trackers. In October in Southern California, a trail cam photographed a female mountain lion in the Hollywood hills. That lion could end up as a mate for the famous P-22, the male mountain lion who lives in Los Angeles at Griffith Park, just east of Hollywood.
Bears
Wildlife biologists will tell you that the attempt to count bears and document their behavior was once a huge guessing game. In 1981, they estimated the bear population at 10,000 to 15,000. Now, with GPS collars and trail cams, the estimate is 25,000 to 30,000, and many believe the figure is higher. This past summer, in a four-week period, my trail cam in forest along a game trail photographed seven bears, a personal high. In the Ukonom Basin of the Marble Mountain Wilderness, scientists were able to count 40 bears in 10 square miles, the highest bear density outside of Yosemite. I’ve camped at Ukonom several times and always had nightly visits. With GPS collars on bears, scientists have verified that, in the fall, bears often migrate to oak woodlands to gorge on acorns, then return in early winter to the mountains to hibernate.
Rocky Mountain elk
Trail cams, GPS collars and DNA studies have solved one of the biggest wildlife mysteries in North America: the decline of Rocky Mountain elk populations in the greater Yellowstone region. Every spring, grizzly bears once feasted on spawning cutthroat in Yellowstone Creek, which would migrate upstream from Yellowstone Lake. With few cutthroat, scientists say that grizzly bears turned instead to newborn and juvenile elk to replace the meat/fish their diets require in the spring. The result has been a series of years with poor survival rates of juvenile elk and, in turn, a population decline. In a wildlife detective story, park scientists used the new technology to trace the elk decline to the introduction of non-native mackinaw trout that feed on native cutthroat trout in Yellowstone Lake.
Coyotes
A coyote on a rooftop last month — on a commercial building south of Market in San Francisco — may have been the strangest of all the coyote stories to emerge. Wildlife cams have verified the presence of coyotes in many surprise encounters. The coyotes’ ability to adapt and thrive in urban settings is even better verified in Los Angeles, where there have been hundreds of coyote sightings. Most are on city streets, and not just near Griffith Park, but also Echo Park, Hollywood and Westlake.
Sierra bighorns
The new wildlife technology has been a critical piece to help the DFW restore populations of endangered Sierra bighorn sheep. In the late 1990s, DFW said about 100 Sierra bighorns remained. DFW scientists were then able to identify and kill 24 mountain lions that they said were targeting bighorns. This, along with efforts to keep bighorns insulated from disease from domestic sheep, has helped the population expand to roughly 600. The Mountain Lion Federation has supported the recovery, no small concession. “When there were thousands of Sierra bighorns, the size of the herd could handle occasional predation,” said Tom Stephenson, who heads the Sierra Nevada Bighorn Sheep Recovery Program for the Department of Fish and Wildlife. “When you have a few hundred animals of a species left in the world, every individual becomes important.”