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Bears that normally hibernate in winter are active in February heat wave


NPS / Yosemite National Park A mother black bear pauses in forest near Hetch Hetchy in this photo shared Saturday on multiple social media platforms by Yosemite National Park staff.

It’s so warm and dry right now in the Central Sierra, some bears that normally hibernate in the coldest depths of winter are active, out and about, and looking for food.

A cinnamon-colored mother bear and her cubs have been spotted and photographed in the Tuolumne River watershed, near the Hetch Hetchy entrance station to Yosemite National Park, and a smaller, light-brown bear has been seen in the Merced River watershed around Yosemite Valley.

Bears are awake and active in early February, snowpack is melting, people are sunbathing and thinking about swimsuits, and the current heat wave that started more

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It’s so warm and dry right now in the Central Sierra, some bears that normally hibernate in the coldest depths of winter are active, out and about, and looking for food.

A cinnamon-colored mother bear and her cubs have been spotted and photographed in the Tuolumne River watershed, near the Hetch Hetchy entrance station to Yosemite National Park, and a smaller, light-brown bear has been seen in the Merced River watershed around Yosemite Valley.

Bears are awake and active in early February, snowpack is melting, people are sunbathing and thinking about swimsuits, and the current heat wave that started more than a week ago is supposed to carry on past Valentines Day next week.

“As far as we can tell, the next week and half looks dry, and probably longer as well,” Tom Dang, a meteorologist with the National Weather Service in Sacramento, said Tuesday. “The last rain in Sonora was Jan. 25. This streak of 60s or greater started Jan. 28.”

One local record for the daytime high temperature was tied Sunday when it was 69 degrees in Groveland, equaling a mark set in 2009, Dang said. The two hottest early Februarys on record in Sonora since 1902 were in 1962 and 1965, when it was at least 5 degrees warmer each day than it’s been so far this February.

It’s not unusual to have warm, dry spells in winter in the Central Sierra, Dang said. Even in extreme wet winters like last year, there were brief breaks from storms and cold. But the current heat wave is the second one so far this winter, counting one in December, which was drier than normal.

Water supply

Many of the Golden State’s major reservoirs, including New Melones and Don Pedro, are more than 80 percent full due in part to the near-record wet winter a year ago. But snowpack for the Central Sierra this week showed snow water equivalents of just 5.8 inches, 30 percent of average for the date Feb. 5.

Tom Haglund, general manager for Tuolumne Utilities District, says there’s still a lot of winter left for more storms and colder weather. But if warm, dry trends continue, conservation measures may be in store for 44,000 people who get their water from TUD.

Current snowpack in the South Fork Stanislaus watershed that includes Pinecrest Reservoir is similar to what it was in early February 2014 and 2015, Haglund said. Thanks in part to last winter, reservoir levels are quite a bit higher this year compared to the same date in 2014 and 2015.

“For the time being, this storage is providing us some buffer as we monitor the weather,” Haglund said. “It is important to note that even as dry as conditions were in 2014 and 2015, Lyons and Pinecrest reservoirs did eventually fill and spill.”

Feb. 1 storage at Pinecrest was 3,000 acre-feet in 2014, 6,200 acre-feet in 2015, and it was 10,500 acre-feet a few days ago. Hopefully that means Pinecrest will fill and spill this spring, in spite of the current heat wave.

“We are still short of snow for this year however, we do have a few months left where we normally do receive precipitation and snow,” Haglund said. “If we get anywhere near normal amounts in March, April and May, then Pinecrest is likely to fill and spill this year as well.”

If forecasts and conditions continue to remain dry through about March 1, Haglund said, people at TUD may begin to alert customers of water supply conditions and possible water conservation measures.

Bears awake

Yosemite National Park staff put photos of active bears on Twitter, Instagram and Facebook over the past weekend.

“Be aware: Some bears are still active at lower elevations in the park!” park staff posted.

Black bears don’t always den in the winter, park staff said in their post. If food is available year-round, many bears decide to skip their winter naps. Pregnant sows always den because they give birth during hibernation to protect newborn cubs during their first few weeks of life.

Asked Tuesday for perspective on how the early February heat wave is affecting bears and other animals, John Buckley with the Central Sierra Environmental Resource Center called from Yosemite Valley.

“Here in Yosemite today, it’s T-shirt weather, people are in shorts,” Buckley said. “In the sun it’s incredibly warm. Over in the shady side of the valley it’s cooler, some people are in down coats. It feels like about 70 over here.”

On Monday this week, CSERC staff set up wildlife cameras in several locations in the Stanislaus National Forest to try to keep track of Pacific fishers, ringtail cats, American martens and other special status species.

They are fur-bearing animals with very thick coats that tend to hang out where it’s coolest in the Central Sierra, Buckley said. They choose to minimize their exposure to heat, and none of them hibernate.

“This exceptional weather is affecting wildlife,” Buckley said. “When it’s warm weather, the bears don’t stay hibernating. They’re moving around.”

‘Heat wave in winter’

People will see bears in Yosemite and other places, Buckley said. They’ll come out because they’re hungry. In some Stanislaus National Forest communities, and even down into the foothills near New Melones, bears will be out at lower elevations.

“This is truly like a heat wave in winter,” Buckley added.

For bears at elevations of 7,500 feet, 8,000 feet and higher, the current warm, dry spell is less intense and it’s more likely they are still hibernating.

The challenge for active bears right now is finding enough to eat when food is limited. One of the reasons they hibernate in winter is because food supply is typically scarce.

“It can be stressful for them this time of year because they’re struggling to find fresh, green growth and acorns from last fall,” Buckley said. “The limited food means it’s an added stress for species that have to go through a long time without eating. Now they’re out and about and they’ve got to find food because they’re moving around and burning more calories.”

It’s so warm and dry right now, and so much snow is melting, some people are talking about whether Tioga Pass will open early.

“Back in the drought we had access to Tioga Pass in late January,” Buckley said. “It could happen again. It’s so exceptionally warm right now, and there’s very little snowpack at the moment and that could melt off fast.”

A National Park Service list of Tioga Pass closing and opening dates going back to 1980 shows the latest closing date was Jan. 17, 2012. The earliest opening date for Tioga Pass since 1980 was April 29, 1988. Warren Alford with Caltrans District 10 in Stockton says the earliest opening for Sonora Pass was April 8, 1977. The earliest opening date for Ebbetts Pass was March 28, 2003.

Contact Guy McCarthy at gmccarthy@uniondemocrat.com or (209) 588-4585. Follow him on Twitter @GuyMcCarthy.