Nature’s notebook

Gardener plus shovel equals treat for savvy robin

Robin sits, waiting for gardener to dig up more worms. Photo: Ruth Ann Grissom

Digging a hole is one of my favorite garden tasks. I’ve refined my technique over the years, using a stance that protects my temperamental back. The work is satisfying on many levels. I appreciate an upper-body workout that doesn’t require a trip to the gym, and the earthy smell of topsoil enriched by decomposing leaves can be intoxicating. When the soil is just right – moist but not soggy – the clay yields to the shovel and clods break into a uniform crumble. When the weather is pleasant, I can dig for hours on end.

During the cool, wet spell we enjoyed in early May, I couldn’t resist the urge to plant a few new shrubs and relocate a few others. I needed maybe half a dozen holes. As I moved methodically from spot to spot, I noticed I was being followed by a robin. Since his head was slightly darker than his back, I figured it was a male. He appeared fearless, getting within a couple feet of me. Nearby, a spotty juvenile lurked around the base of some existing shrubs, fluttering its wings and emitting plaintive chirps. I felt as though I’d transcended my species. I fancied myself at one with nature, recalling statues of St. Francis with birds perched on his shoulders and in outstretched hands.

I was soon disabused of such romantic notions. The robin was obsessed with the worms I had unearthed. He had a baby to feed, and I was simply a means to his single-minded goal. I paused and watched him more carefully. He would run to the edge of the hole where I had shoveled out a pile of dirt. He’d stop there, flicking his tail and cocking his head. He’d pluck a worm, and another, and another until he filled his beak with wriggling invertebrates. After delivering them to his baby, he’d perch for a while on the power line, belting out his song. Cheerily cheer up! This is my territory! Cheerily cheer up! These are my worms! Once he’d warded off his competitors, he returned to the task at hand.

If I resumed my work, he’d hop just beyond my reach until the shovel rested again. He’d raise the feathers on top of his head and stare at me with that rapacious white-ringed eye, as if he were indignant at the wait. I was struck by his cleverness. Robins haven’t always relied on backyard gardeners to help them feed their young, so at some point they learned this behavior could be successful.

Crows have long been recognized for their intelligence. They are adept at crafting tools to help them forage and defend their nest. Other birds also exhibit similar behavior. Brown headed nuthatches break off pieces of bark and use them to probe crevices in tree trunks for insects.

Robins have taken a different tack, using humans to assist their foraging. Unlike pigeons that gather in urban parks for handouts or gulls that flock around fishing trawlers to scoop up chum, robins are procuring a food they’d naturally eat. We just make it easier for them. Cowbirds and gulls exhibit similar behavior. They now follow tractors and combines for easy pickings. So do cattle egrets, a species that was historically associated with grazing mammals. According to the Cornell Lab of Ornithology, they also realize insects will flee a wildfire, so they have learned to fly in the direction of smoke.

Robins continue to probe for earthworms and other invertebrates in forested areas, but they have adapted exceptionally well to human-altered landscapes. Their numbers have probably increased since widespread land clearing following European settlement. Their close relationship with humans does have some downsides. They’re vulnerable to poisoning from chemicals applied to lawns, flying into plate-glass windows and falling prey to house cats.

While I thoroughly enjoyed my backyard interlude with the robin, I was reminded that many bird species don’t tolerate such intimate interaction with humans. The wood thrush, for example, needs large tracts of undisturbed hardwood forests. From its perspective, our stewardship of woodlots is just as important as digging holes.