Vireo

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The rough-hewn path through the forest was strewn with the spent flowers of madrone – tiny, white, urn-shaped orbs that lent lightness to the trail. Near the end of April, the mixed woodland glowed in shades of green, gold, and chartreuse. The air was still brisk but soft. It was full on spring.

My morning walk with a birding pal held promise. We were looking for warblers - a spring ritual. Zeedle, zeedle, zeedle, zeet. Oh, there’s a black-throated gray in the canopy. Good start.

We noted the last of Calypso and the coming of spotted coralroot and woodland starflower in the duff. Robins chortled, an orange-crowned warbler trilled, and a varied thrush’s haunting call wafted through the trees. We rounded a bend, scrambled up a steep incline and emerged in a clearing then stopped to scan for birds and simultaneously pointed to a nest in a madrone downslope from the path.

It was a tiny, woven cup of twigs, leaves, fibers, lichen and spider silk suspended from a bough. The outside of the vessel was adorned with flower petals and spider egg cases. Overhead, a tangle of branches and greenery offered cover and camouflage for the nursery.

What seemed a precarious perch was a sturdy structure testimony to the wonder of animal architecture. A little gray-headed bird with a white throat sat motionless in the basket of eggs peering over the rim at us through sparkling, dark brown eyes. I used a long lens to take a photo then quickly departed so as not to disturb its tranquility.

Later in the day I took to books to identify the little forester - likely a Cassin’s vireo (Vireo cassinii) one of four vireo species found in the San Juans. It was named for 19th century American ornithologist John Cassin also known for Cassin’s auklet and Cassin’s finch among other species.

Cassin’s vireo is an understated bird: medium-sized, mostly olive-green above, whitish below with a hint of yellow wash on its flanks. It is a common breeder in western forests from British Columbia south, and winters in Mexico. The insectivore gleans from vegetation in the mid-tree zone and sometimes hawks and flycatches. It favors caterpillars, beetles, moth eggs, ants and other arthropods.

There are two conspicuous identifiers for this vireo; one is its white spectacles and the other its song. The male Cassin’s sings incessantly in the woods adding to the chorus of nuthatches, chickadees, juncos, robins, thrush, flycatchers and others that form the sylvan bird community.

The song has been described as a series of high, clear whistled phrases with rising and falling inflections.

William Dawson in The Birds of Washington elaborated: “Cassin sings as he works; and, as he works a good deal of the time, albeit in leisurely fashion, he sings in tiny phrases, separated by unembarrassed intervals of silence, a sort of soliloquizing commentary on life, very pleasant to the ear.”

My photo of the bird was not definitive. I needed to see its spectacles and hear its song and so it was back down the dawn road the next morning to take another look. As I got out of my car the spirited strains of the vireo were echoing through the trees. Good! Now to confirm those white spectacles.

The morning sun shone through the celadon leaves of big-leaf maples as I headed for the nest. The bird was perched high in the cup and through binoculars I could see its white spectacles. Yes, it was a Cassin’s.

I settled into the shadows nearby to watch for the mate. Both parents participate in brooding eggs and raising offspring. The vocal male would arrive soon – I hoped. An hour went by and then two. I listened to woodpeckers drumming, warblers warbling, and bees buzzing, but no vireo. The sun rose over the ridge and shone directly on the nest. The female adjusted her position to take full advantage of the warmth.

I moved down slope to investigate wildflowers. The vireo started singing. From my new vantage point I could see the male flitting through layers of green leaves asserting his territory through vigorous song. He paused in a madrone close to the nest and poured out wild notes with a steady cadence. The breeze picked up the melody and nudged it through the trees. He was magnificent.

Then the switch. In an instant, the male dropped down to the nest tree and hesitated only a moment on the natal bough while the female flew out and away. He quickly settled over the creamy white and speckled eggs for his turn at incubation. His shift started at 9:56. I retreated – smiling – in the opposite direction.

So, what does it matter – this pair of little olive drab songbirds arriving under cover of darkness from Mexico to raise the next generation of vireos in a San Juan Island woods?

From a practical standpoint, Edward Howe Forbush put it well in Birds of America when he wrote: “This vireo is one of the conservators of the forest – a caterpillar hunter of renown – one of a number of arboreal birds which guard the trees against the too destructive attacks of quickly multiplying scaly-winged hosts.”

In other words, the vireo has its place and function in the web of life helping (along with the other spring breeding birds) to keep biological balance in the forest.

It also matters that this woodland remains relatively intact for migratory birds and butterflies and resident wildlife. By identifying the vireo’s continuing use of this site the value of preserving wild habitat is reinforced.

For me, there is more than the science and practicality of it. There is heart and soul, too. What does persevering to see a beautiful little bird sing its heart out in the dappled green and gold canopy of a sublime woodland do for ones spirit? It makes mine soar. The vireos have their place in the world as we have ours. Sometimes those places overlap and we are privileged to observe the intimacies of their lives as we embrace our own. The experience may last only for a moment and then be gone. Perhaps it is a good thing to celebrate that moment.


References: Dawson, William L. The Birds of Washington, 1909. The Occidental Publishing Co, Seattle; Goguen, Christopher B. and David R. Curson. 2002. Cassin’s Vireo (Vireo cassinii), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/615doi:10.2173/bna.615; Birds of America, 1917. T. Gilbert Pearson ed. III. Page 107. Garden City Publishing Company, Inc. Garden City, New York.


San Juan Nature Notebook / Vireo / Text and photograph copyright 2016 by Susan Vernon. Susan Vernon is the author of Rainshadow World – A Naturalist’s Year in the San Juan Islands. Contact: susanvernon@sanjuanislander.com

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