Wild, Wild Life

Black-headed grosbeaks are now singing in the Valley, there were more orioles on Thursday's birdwalk, and several dozen yellow-rumps encountered in 3 flocks -a tiny portion of them singing. Three Vaux's swifts patrolled over the Valley Visitor Center. Hummingbirds are doing display flights. About a month ago NPS volunteer interpreter Kirsten discovered a rare Virginia Rail near the boardwalk in Cook's Meadow.
On the mammal side, a dark brown bear has been grazing the Ahwahnee Meadow area lately. Two rescue helicopters there on Tuesday night didn't disturb its feeding. Biologists researching our fisher populations are delighted to have encountered a mother with young, moving them from place to place in the south area of the park. Good news for predators and general food web health; bad news for mice and squirrels.
Road crews are grinding away at the extra-deep snow on both Glacier Point and Tioga Roads, slowly making progress to open up the high country for our cars. Tomorrow morning might be cold enough for frazil production, but then it warms up for the early part of the week. There is still a chance for big frazil flows for another few weeks; just because April's over doesn't mean that we won't have some sub-freezing nights in Yosemite Valley.

Slow spring

Too warm for frazil ice, too cool for rapid snowmelt, our recent unsettled weather continues this week with a bit of cloudy damp. The weather forecast leads us to anticipate no frazil ice this week.
Black oak leaves are not quite starting to burst out of buds yet, though they have lower down. Cottonwood flowers are out along the river. Insectivorous orioles are in the Valley now, ahead of most insect food. Redwings are singing in Cook's Meadow, mallards swim in pairs, yellow-rumped warblers sing a bit on sunny days.
Former Yosemite employee Paul Keel, back for a visit, added a new species to the park's birdlist: our first ever white-faced ibis. Paul is a state park ranger now, down on the coast, and he got good photos of the ibis in El Capitan Meadow. You never know what you'll come across, if you're paying attention.
This morning we watched a male belted kingfisher working the oxbow lake in Cook's Meadow. Fun to see a fish predator well away from the river channel.
More predators will be on display in the Conservancy's "Hawks and Owls" field seminar the first weekend of June. Park ornithologist Sarah Stock and great grey owl specialist Joe Medley (yes, the son of Steve Medley) are the two instructors. We are delighted to have these two knowledgeable experts (and charming individuals) teaching this fun program. There's still space available; free camping and free park entry are part of the package. Raptors rule the skies...

National Parks Week

I am back in Yosemite after two weeks away, and what changes there are. The free entrance to Yosemite for National Parks Week, combined with some school spring breaks has meant a busy week in the park. The natural scene is busy, too.
Snow is gone from the Valley floor except in a few shady spots. Waterfalls are bigger than average, with the recent warmth getting a start on melting off our exceptional snowpack. Cooks, Leidig, El Capitan, Stoneman, Ahwahnee and Slaughterhouse (lovely, I know) Meadows all have standing and/or running water in them now; some paths are blocked, but none of the main ones yet. Table Rock, our local visual river gauge for Valley commuters, is underwater.
Frazil ice forecast for this weekend: POOR.
Yellow-rumped warblers are at their brightest in the black oak canopies, where tiny pink leaves are barely starting to emerge in the Valley. Black-throated gray warblers are doing their excited, buzzy call in the live oaks in the Valley now, too. A great gray owl was reported on its nest up near Crane Flat, though there's so much snow there still, their food is out of reach and it's hard to imagine successful breeding at this point.
Our "Moonbow Photography" Outdoor Adventures course was a success on Sunday night, with a bright bow visible for a couple hours in-between overcast periods. Next up is Ken Rockwell and Dave Wyman's "Spring Light Photography" course, and then an excellent "Hawks and Owls" program the first weekend of June.
Our regular public birdwalk will be seeking John Muir's favorite bird tomorrow, Cinclus mexicanus. Thursday is his 173rd birthday. Friday is Earth's birthday; stand up for what you stand on, as they say.

Yosemite Recovered

The storm of 20-21 March goes into the record books as one of the most significant in decades: over 12 feet of snow at the 7-8000' level, and 9 inches of heavy snow that broke down thousands of live oaks and other trees at the 2000' level. Electricity was restored after 6 days, and visitation has now picked up.
We've had very warm weather the past few days. Bird activity has increased, flowers are on the rebound, and the Merced River has doubled in volume and is really turbid. The river has gone over 1500 cfs at Pohono Bridge, more than twice the average flow for this date. Sierra-wide snow surveys show 165% of normal water content in the snowpack; our local results come out shortly and will surely be comparably abundant.
We all look ahead to the waterfall season of the next 3 months, hoping that all this snow runs off over a long span of summer, rather than all at once. Photographers Ken Rockwell and Dave Wyman have timed their "Spring Light Photography" course to coincide with predicted high volume, 19-22 May.
We're also coming into peak frazil season this month. The frazil ice forecast is poor for the next few days, as temperatures are mild. But the warmth makes more mist, which will produce more frazil particles when the temperature does drop again.
I'll be away from the park the next two weeks.

Yosemite Recovers

Electricity is supposed to be restored to El Portal and Yosemite Valley today (Saturday). Most park roads are now open, though with chain restrictions on all of them. Highway 140 is closed between Mariposa and El Portal by a rockslide near Briceburg; it should be open by Monday or sooner. Badger Pass is closed, but hopes to open for its last weekend of the season, April 1-3. There is over 14 feet of NEW snow at Badger!
The Valley floor has 1- 1.5 feet on it. DNC is using these rare conditions to lead springtime snowshoe walks from the Ahwahnee this weekend. The Visitor Center is fully staffed, and a few visitors are trickling through. It's snowing in the Valley now, but snow isn't sticking much below the 3500' level. Though Hwy. 41 is open, buses are being turned away from the south entrance at the moment. You MUST call 209/372-0200 to check on road conditions before heading to the park.
The Conservancy's annual Spring Forum was supposed to be held today, but conditions obviate that possibility; we'll try again next year. Tomorrow's wildflower field seminar in El Portal is also cancelled; Michael Ross is teaching two other botany courses in the summer where we hope snow won't be a factor.
Warm weather returns to the Sierra next week, with sunny and low 60's in Yosemite Valley. We should see a big spike in runoff by late in the week, with lots of wet meadows, though we probably won't really approach flood level. It's going to be a terrific season for Yosemite waterfalls.

Yosemite Closure

An unusually cold and wet storm has delivered a lot of snow, causing extensive tree damage in Yosemite. All roads into Yosemite are closed. Power is expected to be out for 5-7 days. At under 2000' El Portal got 8-9 inches of snow, something not seen in decades. Most of the damage is to live oaks, with hundreds of trees and large limbs down in El Portal alone. The rest of the Merced Canyon has numerous small rockfalls and landslips partly blocking roads between Mariposa and Yosemite Valley. The snowfall took place mostly overnight on Sunday. Skiers exiting Ostrander Hut on Sunday worked as a 20-person team to break trail. They scooped up others along the Glacier Point Road who had dropped from exhaustion pushing against the heavy accumulation. When they reached the trailhead, they couldn't leave Badger Pass; about 60 people spent the night in the day lodge at Badger. Yosemite West has run out of water and all residents and guests have been escorted out of the park. Community meetings later today will tell us more, but it's possible that the park will be closed and all remaining visitors and non-essential employees evacuated. The generators that keep the lights and heat working can only do so much, and they're needed to operate water and wastewater systems, too.
I'll post more when I can.

Wintery Equinox

Yosemite Valley's mostly bare ground got a few inches of snow overnight and it even accumulated as low as El Portal; most park roads are R2 this morning. Another wave of snow arrives early Sunday morning.
We had frazil ice in the Valley this week, with Yosemite Creek sending frazil into the Merced twice, and Ribbon Creek even fraziling all the way into the river on Thursday. The snow cone at Upper Yosemite Fall is as big as ever. Frazil forecast for the next several days: moderate, best on Monday morning.
Sentinel, Eagle and Horsetail Creeks flow to the river. Wosky Pond is very full.
Varied thrushes, which have not been very evident here this winter, were making their odd squeaks in Yosemite Village yesterday. Karen Amstutz and Michael Ross heard and saw a phainopepla in El Portal earlier. Karen noted a disoriented flock of Canada geese in the rainy nighttime of Badger Pass last weekend, likely drawn to the illuminated slopes.
Tonight's full moon coincides with perigee (the point in its elliptical orbit where it's closest to earth) so will appear a bit larger and about 15% brighter than an average full moon; this happens about every 20 years. Elsewhere in the sky this weekend: vernal equinox on Sunday when the sun rises due East and sets due West, and our day and night are about equal in time. Vernal means springtime, so Sunday is the first day of astronomical spring for the northern hemisphere. Vernal also is a big waterfall that will be running strong this season - given its current name by the first Euro-Americans in the Valley who saw its ferns and moss as springlike. Just upstream was a bigger, but somehow colder-looking waterfall that they named Nevada, meaning snowy.
This weekend is thus both 'vernal' in astronomy and 'nevada' in weather - Yosemite perfection.