Evolve or die

 

Cross-posted from.

Updated 2-21-2012 to correct image of chipmunk.

Several years ago, on a soggy but majestic mountain afternoon, I hiked into the Yosemite backcountry to meet UC-Berkeley mammalogist . Patton and his colleagues at the Museum of Vertebrate Zoology were retracing the steps of renowned naturalist , who surveyed California’s wildlife early in the last century — and obsessively documented his work in voluminous, barely legible field journals. (Fellow archive nerds, see some wonderful examples .)

Thanks to Grinnell’s tireless note-taking, Patton and his team were able to repeat the surveys, and get a sense of how Yosemite’s wildlife has changed over the past 90 years. Of the 30 mammal and bird species studied by both Grinnell and the modern-day Berkeley team, 14 show no significant change in their range, but 16 have shifted their habitats, with lower-elevation species consistently expanding their range uphill and higher-elevation species — the pika, the alpine chipmunk — retracting the lower limit of their range. The pattern suggests that many of Yosemite’s critters are already responding to climate change, and habitat models developed by the researchers strengthened this conclusion.

But that’s not the end of Grinnell’s legacy.

Delving into the deep Museum of Vertebrate Zoology archives, the Berkeley team sampled skin from the actual alpine chipmunks Grinnell trapped in Yosemite nearly a century ago, had the samples analyzed at a lab specializing in ancient DNA, then compared the results with a similar genetic analysis of the park’s current alpine chipmunks (While Grinnell and other naturalists of his time didn’t hesitate to kill critters in the name of science, today’s researchers are more restrained: The modern samples came from probably unpleasant but non-lethal chipmunk ear punches.) In , Emily Rubidge and her co-authors report a decline in overall genetic diversity within Yosemite’s shrinking population of alpine chipmunks, as compared with another Yosemite chipmunk species that has stayed put since Grinnell’s time. The analyses also suggest that as the alpine chipmunks’ range retracts uphill, their once-free-flowing population is becoming isolated into small subpopulations.

For animals whose habitat is soured by climate change, there are two options. Well, three. They can move to a more tolerable climate. They can adapt — genetically or behaviorally — to the new conditions. Or they can go extinct. For species like the pika and the alpine chipmunk, which already live on islands of habitat above treeline, the first option is literally a dead-end strategy. Can they take the second, and evolve their way out of a bad situation?

I recently edited a fascinating NewTowncarShare News story by my friend , which describes how the rate of coat-color change in snowshoe hares may be responding to changing snowfall levels. Luckily for the hares — and for the Canada lynx that dine on them — snowshoe hares are still plentiful and diverse, making small, relatively fast evolutionary adjustments more likely. For species like the alpine chipmunk, survival means not only outrunning the heat in the short term, but also slipping through a narrowing genetic bottleneck.

Some species will survive the squeeze; some won’t. But what’s certain is that Yosemite, down to its smallest mammals, is no longer the place Joseph Grinnell once knew so well.

Yosemite chipmunk photo courtesy Risa Sargent

Joseph Grinnell photo courtesy of the UC-Berkeley MVZ.

Michelle Nijhuis is a contributing editor at NewTowncarShare News.

NewTowncarShare News Classifieds
  • Join the publisher, editors, writers and staff of NewTowncarShare for the annual Holiday Open House. Refreshments, food, door prizes and merriment. Thursday, December 6,...
  • 5 acres, views, utilities to lot line includes paid water tap, great for passive solar design, covenants and NO HOA. Listed by Beckie at Keller...
  • The Native American Fish and Wildlife Society (NAFWS) is seeking qualified applicants to fill a vacant Executive Director position in Denver, CO. The position serves...
  • The Western Environmental Law Center (WELC) is a nonprofit public interest environmental law firm with a 25-year legacy of success using the power of the...
  • 383 Acres with trails, private road, trees, stream and fabulous views. Earth Sheltered, passive solar home provides 2785 sf of comfort and a "top of...
  • certified, 51 acres, small cottage, outbuildings, equipment and tools. Contact: [email protected]
  • 2bd/2bath green home on 2 acres on the Ojo Caliente River, NM. MLS #101605. Contact [email protected]
  • of mountains, 22+ acres. Close to Arroyo Seco and the Taos Ski Valley, NM. MLS #102585, [email protected]
  • 2br-2ba, acreage. Birders, writers. 1000.
  • 1400 sf of habitable space in a custom-designed eco-home created and completed by a published L.A. architect in 1997-99. Nestled within its own 80-acre mountain...
  • The Wilderness Society is currently recruiting for a Communications Manager for our Northwest Region. This position can be located in Seattle or Oakland. For more...
  • 1912 Orchard House completely rebuilt 2002. 4000 sq ft home and private guest cottage on .53 acres. Reclaimed maple and Doug Fir. Two garages. CathyMooney.com,...
  • with home on one acre in Pocatello, ID. For information and photos visit www.blackrockforgeproperty.com.
  • Public Employees for Environmental Responsibility (PEER) seeks a new Executive Director to guide this dynamic national advocacy, watchdog, and service organization. The successful candidate requires...
  • The California Program Manager will work closely with California-based program staff and other NFF staff to provide project management and program development support. The incumbent...
  • Sierra Club is looking for a community organizer who can help us protect grizzly bears and other wildlife species in the Northern Rockies region. This...
  • Join HCN and Black Sheep Adventures on an expedition through the national parks and monuments of Utah and Southwest Colorado, September 7 - 15, 2019....
  • Grand Staircase Escalante Partners is hiring a full-time Restoration Program Coordinator based in Escalante, Utah. gsenm.org
  • 7.58 Acres in Delta County for $198,000. and a contiguous 25 acre parcel of land zoned agricultural is available in Montrose county for an additional...
  • in Moab, UT start in Spring. Naturalist, River Guides, Camp Cooks, Internships available. Details at cfimoab.org/employment.