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Re: American pika disappears from large area of California's Sierra Nevada mountains

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avatar American pika disappears from large area of California's Sierra Nevada mountains
August 31, 2017 11:24AM
The American pika, a small mammal adapted to high altitudes and cold temperatures, has died out from a 165-square-mile span of habitat in California's northern Sierra Nevada mountains, and the cause appears to be climate change. Researchers surveyed pika habitat throughout the north Lake Tahoe area and found that pikas had disappeared from an area that stretches from near Tahoe City to Truckee, more than 10 miles away, and includes Mount Pluto.

https://www.sciencedaily.com/releases/2017/08/170830202154.htm
more bad news, but its been coming now for a number of years, or so I believe. I was lucky enough to see one part way up the 'golden staircase' a few years ago, where not a lot grows. apparently there's a lack of food at the altitudes they live at.White flag
Hm... I thought their little bodies are so adapted to cold temps that even a small increase in average temps causes them difficulty... ? But where did I read that..? Was a while ago..

Anyway... basically a whole month plus in the Sierra from Northern Yos to southern Sequoia... lots of time over 10k'... including almost a week between 10-12k' straight... lots of marmots... zero pika sightings and no recall of hearing their alarm cry.. very sad..
Re: American pika disappears from large area of California's Sierra Nevada mountains
September 11, 2017 05:46PM
I recall hearing of the pressure on pika habitat, linked to climate change.

Luckily, they aren't all gone, even from the Sierra. Saw a few, and heard many more of the little critters between 10-12k' on the east side just last week.

In addition to the altitude/temperature, I believe they also prefer very rough boulder fields. At least, that's the only places that I've ever seen them (not claiming that's definitive).

They sure are a lot of fun to hear, and even more fun to actually see them. When they sound the alarm, their whole body seems to be recruited into the effort - they may even leave the ground for a moment... :-)





Edited 4 time(s). Last edit at 09/12/2017 08:25AM by ags.
I've mentioned before, I think...

But the only creature we have ever seen scratching at our bear can was a pika! Once they are used to you, they are immensely curious...

It ran right next Basilbop and stood on its back legs and scratched at the can for some time. It was 2 feet from Basilbop. Neither of us moved so as not to scare it, but no cameras nearby!

Another cute visitor was at Moose Lake, where it came right into camp and chomped on some flowers. We got a pic of it. It's in the thread Moose Redux. Being lazy and not copying link as I'm on my phone. May do in a bit...

But this year, no alarms, no sightings. Unusual. Glad you saw them!
Re: American pika disappears from large area of California's Sierra Nevada mountains
September 12, 2017 08:35AM
Finally remembered how to link a photo... (above)
Would expect the 4 year drought caused significant species declines of numbers of species in many Sierra Nevada areas including pika at marginal elevations per that report. Without snow covering ground that provides an insulative layer, animals are subject to harsh atmospheric cold. As a snow skier, have also noticed the last decade has generally had rather mediocre early season snow. During the previous couple decades, skiing at Thanksgiving was a gamble but during this last decade the same could be said about the Christmas holiday period. Without snow cover, at marginal elevations, cold rains during the period cause ice at the near surface soil areas where such small mammals live. Another issue is a source of water. The marginal elevations during the drought dried out early in May and June causing plants they eat to have a short early cycle versus normal June through August. Thus some may have died from lack of water.

During the last couple years of above normal precipitation, the reverse occurs as species extents expand. One lush productive zone where expansion did not occur were along riparian areas as many streams rose to decade highs levels. Any animals living near such streams that did not manage to scurry up above flood levels perished. And within streams those high flood levels certainly took a toll on trout unable to cope with the raging torrent levels. To the south in the High Sierra there are areas where pika no doubt also declined but for opposite reasons. Some of the shady high altitude areas have had decades high levels of summer snow. In some cases creatures that had moved into those areas, could not escape from beneath feet of snow have no doubt perished.

Many of us were rather surprised at the low numbers of one species that after wet El Nino years often explodes. That is not to say that species was dense in some local areas but rather over the full range, many reports showed piddly numbers. And that is the mosquito that apparently took a significant hit during the 4 year drought that a single really wet winter was not enough to quite bring back to normal.

During my 3 backpacks this summer in the High Sierra I saw usual numbers of pika, and also saw a few pika on my one backpack at Desolation that was also significantly higher than the Truckee zone.


David




http://www.davidsenesac.com



Edited 1 time(s). Last edit at 09/12/2017 10:53AM by DavidSenesac.
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