Birds Nest Fungus & Hope

Sunday, March 20th, 2016

After a string of windy and bitterly cold days that has turned most everyone cranky, today dawned still and fair. And although the air temperature was only 10 degrees F at dawn, once the sun came up, the air warmed quickly, rising to 60 degrees by early afternoon.

I decided to take advantage of the day of spring-like weather to wash my windows, which were liberally streaked with wind-blown dirt and pollen. I got out my stepladder, squeegee and swab, and my bucket, filled the bucket with hot water plus vinegar, and took my gear out to the sun-warmed front deck. 

Once the large windows on that side of the house that harvest solar energy in winter for my heat were sparkling clean, I hauled the stepladder, bucket and washing tools around to the back side of the house to wash my office and bedroom windows. 

As I set up the stepladder, I noticed something unusual on the surface of the soil. I bent down to look and saw a scattering of tiny cup-like structures, each no bigger than my littlest fingernail, and containing two or more flattened disks with a slightly pearly luster. 

I stared for a moment and then smiled. I knew exactly what the odd cups and their egg-like contents were: birds nest fungus. These fascinating little lives are saphropytyes, meaning they get their nutrition by decaying tissues, in this case, the local wood chip mulch I spread lightly over my native seed mix the fall I moved in, a little over two years ago. 

The fungal threads excrete enzymes that can break down cellulose and lignin, the structural tissues that make wood inedible to humans, into simple sugars that the fungus feeds on. When the environmental conditions are right, the network of fungus threads begins thinking of sex, or at least sexual reproduction. 

The fungus diverts some of its energy into forming those odd little cup-shaped structures, and within them, casings shaped like miniature, flattened eggs. Inside those casings is where the actual sexual reproduction happens, filling each disk with spores that can sprout into new fungal threads. 

A closer view of the fungal "cups" and their "eggs"

The little "birds nests" are part of the fungus' dispersal strategy. The ones I spotted while washing windows are perfectly shaped so that the force of a raindrop hitting the cup will splash the tiny disks out--they land as far as three feet from the parent fungus. And there, when conditions the soil surface is wet from rain or snow, and the relative humidity of the air is higher than it usually is in this high-desert climate, the spores sprout into a new fungus. 

What made me smile was only partly the whimsical, fairy-like reproductive structures. I am equally delighted by what their presence implies: My junky industrial lot is returning to life. Those seeds I planted are beginning to reweave a native mountain prairie on what for a century or more was an informal track-side dump which, once abandoned, sprouted a dense fur of invasive annual weeds including tumbleweed, kochia, and cheatgrass. 

The birds nest fungus add nutrients decayed from the chipper mulch to the crappy soil (road-base on top of dump), helping the mountain-prairie plants reclaim this once-blighted site, filling the air with color and sound and life as butterflies and native bees zip from flower to flower, along with hummingbirds and songbirds. The fungus cups remind me that healing is possible for we humans and the earth we have so often treated carelessly, given time and patience and love. 

Seeing the birds nest fungus gives me hope. It is, after all, spring, the season of resurrection and life.

My reclaimed mountain prairie yard in summer