Big Wall Ecology

Any naturalist will tell you that life is usually found where least expected.  Life amazingly adapts to whatever environment it finds itself a part of, even those we humans deem as impossibly harsh.  That is certainly the case on Yosemite’s big walls.  As a climber, I have traveled through these areas and have been amazed to witness entire ecosystems thriving thousands of vertical feet above the Yosemite Valley floor.

My second ascent of El Capitan was by way of the Salathe Wall.  We spent four days on the route and hauled bags with nearly one hundred and fifty pounds of gear, provisions, and equipment.  Planning for the trip was like preparing ourselves for going to another planet.  I was surprised, therefore, when I found a Pacific Tree Frog living quite comfortably behind El Cap Spire two thousand feet up the wall.  This frog’s home is a location that takes most climbers years of training, preparation, and commitment to even approach.  He was perfectly camouflaged to the granite and seemed to be well adapted to the realities of living in such a remote and steep environment.  I chatted with a frog ecologist last year and she surmised that the frogs probably commute down to the valley floor every year to reproduce in standing water.

Life amazingly adapts to whatever environment it finds itself a part of, even those we humans deem as impossibly harsh.

Certain tree species in Yosemite have remarkable tenacity.  The Canyon Live Oaks and Ponderosa Pines are particularly prevalent on the cliffs.  They sometimes grow from cracks where no sediment can even be seen.  Some of the earliest technical rock climbing done on El Capitan was performed by naturalists attempting to approach the El Cap Tree, an eighty foot pine growing four hundred feet up the face.  The men sought to determine the tree’s species and discovered it to be a Ponderosa Pine.  Trees also have an intrinsic part in the geologic story of Yosemite as intruding tree root systems are known as one of the many factors triggering the rock fall common to this region.

The birds often become my closest friends while climbing in Yosemite.  The avian acrobatics performed by White-throated Swifts and Cliff Swallows never fail to impress me.  The swifts are particularly present on the dramatically steep Leaning Tower, a wall largely sheltered from the elements due to its overhanging nature.  Swifts are capable of exceeding speeds of one hundred miles per hour in level flight, nonetheless maintaining tremendous grace and control.  I am always careful to avoid disturbing their homes as I tenuously climb over the steep granite faces.  As for the Cliff Swallows, I distinctly remember a day atop Higher Cathedral Spire when seemingly hundreds of them made a particularly extravagant display, their green backs glistening in the sun.  Mountains breathe and the clouds respond, the winds weave swallows into song.

Climbers also sometimes experience close encounters with peregrine falcons while on the wall.  Often they are not seen, they are heard.  A peregrine diving past you at over two hundred miles per hour makes a shockingly loud roar.  Peregrine populations throughout the country dropped dramatically in the 1950’s through the 1970’s due to poisoning from the agricultural pesticide DDT.  Peregrines were absent altogether from Yosemite National Park for over three decades.  Aided by the banning of DDT in the late 1970’s, peregrines returned to the park in 1978 and have made a remarkable recovery.  They were removed from the list of endangered species in 1999 and Yosemite is now the most active nesting site in the Sierra Nevada.  We climbers can help these amazing birds continue their recovery by respecting peregrine closures on walls and crags throughout the park.

We climbers can help these amazing birds continue their recovery by respecting peregrine closures on walls and crags throughout the park.

Seventeen species of bats live within Yosemite National Park.  I spent several nights last year on El Capitan repairing the Waterfall Route from a rock fall that damaged it in 2010.  I always returned to my bivouac before dark because every night at dusk, hundreds of bats would fly out from beneath a roof perched above my camp.  Observing this nightly spectacle while lying on my portaledge was a borderline spiritual experience.  The bats lie in torpor during the day, and witnessing them emerge in mass into the cooler dusk air was beautiful.  I felt connected to the circle of life on Yosemite’s big walls.

 There is a vast array of coloration present on Yosemite granite.  Much of the color is derived from lichen communities that have made themselves common throughout the Sierra Nevada.  Lichen has an amazing story.  It exists through a symbiotic relationship between an algae and a fungus.  The fungus absorbs micro-nutrients and particles from the air, and clings to surfaces like the vast vertical horizons of Yosemite’s walls.  The algae performs photosynthesis and produces carbohydrates for energy.  Together, they form the lichen.  There’s some old ranger humor: Mrs. Algae and a fun guy meet each other and take a “lichen” to each other.  We are particularly watchful of our lichens here in Yosemite National Park because they are great indicator species as to air quality.  They are remarkably effective at absorbing particles from the air, but cannot discriminate between nutrients and pollutants.  Lichens are intimately attuned to their environments and have found all that they require, and nothing wholly detrimental, for their successful population of Yosemite walls.

Yosemite’s walls appear to the uninitiated eye as places impossible for life to prevail.  El Capitan’s monolithic and sheer appearance seems wholly unforgiving.  However, approach the rock and you will find caves, chimneys, and cracks that delve down deep.  There is feature, there are nutrients, and there is water.  Life has found a way to flourish.  From amphibians to trees, birds to lichens, life flourishes on the big walls of Yosemite.