Those are all great pika pictures (though it's hard to go wrong when you do get a photo...).
A study was done on the interior desert ranges and found that rising temperatures has caused the extinction of some populations on some of these "islands" of mountains. What happens is pikas have a very narrow temperature range they can forage in. When it's too hot for too long, they can't get enough food during the day. The 2003+ repeat of the Grinnell wildlife transect of Yosemite, first done in about 1914 - 1920 or so, found that pikas and some other small mammals had moved up about 1,000 vertical feet.
Too much information:
Museum of Vertebrate Biology, Grinnell Resurvey Grinnell Resurvey Pikas I've found this to be true in the southern Sierra. For instance, in the 80s, pikas used to be more common along the San Joaquin south of the Piute entrance to Kings Canyon (8,500'). Now they're pretty much gone (though I heard one two years ago -- but that was the only sighting I had there for years). They don't become common until about 10,000'.
In the Whitney area, they're still common from about Guitar Lake and up.
In Sequoia Kings, Dave Graber, the chief research scientist, has asked backcountry rangers to note the location of all pika sightings. No trend is emerging, but at least we'll have a baseline.
In addition, the belding ground squirrel is losing lower elevation habitat and moving up in elevation. In the 80s, I'd see as many as 20 in McClure Meadow. Two years ago there were maybe 5. Last year there were none. In the last 30 years, they've disappeared from Big Pete Meadow (LeConte area) as well as all of the meadows Evolution Valley (though found on the Darwin Bench and Evolution Lake).
George
