An American Robin hunts worms

 

An American Robin (Turdus migratorius) with a just-captured earthworm. 

Last week, Shauna and I traveled to the Pittsburgh, Pennsylvania area on a whirlwind trip. I was to give a talk (moths) to the Garden Club of Allegheny County on Thursday, so we headed over bright and early on Wednesday to photography waterfalls around the Ohiopyle area.

Upon arriving at our cabin late that day after a photo outing, there was an American Robin on the lawn. Whoop de doo, you might think - robins are one of the most abundant and widespread birds in North America. That's one of their allures, to me. I can go to the wildest northern Michigan forest, midwestern prairie remnants, local parks, urban cityscapes, my back yard, and there they are. The big thrushes are nothing if not adaptable.

But robins are much more than adaptable. The robust caroling song is beautiful and a near ever-present sound of nature. They're showy, too - so much so, that if robins were rare, everyone would go ape over them. Their stout nests are remarkable architectural achievements: an adobe cup that dries to the hardness of a China bowl, and its neatly reinforced with grasses and other vegetation. And the color of the eggs spawned the name of a color: robin's-egg blue.

Anyway, as we took a moment to watch the robin, it suddenly lunged and caught a worm. Cool! Said I, then noted that photographing an American Robin in the act of snagging a worm was still on my bucket list. As there were several robins hunting the lawns, Shauna suggested that I go try and check that item off the list, so I did.

A male American Robin looks and listens for invertebrate prey in the grass. When one freezes, lowers it head and cocks it slightly, action is about to ensue. The robin is using its sensitive ears to listen for worms and other prey, as well as watching with keen eyes.

Bingo! The robin pounces! It has its head way down in the grasses and is about to come up with a favored prey item. I'm not sure the bird could even see the victim and may have divined its location entirely by ear.

PHOTO NOTES: I made all of these images with my Canon R5 and 400 DO II lens. It was coupled to the Canon 1.4xII extender, giving me 560mm of reach. That was plenty. Robins are fairly tame to begin with, and after a while this bird became used to me, and I was typically within 30-30 feet of it. I was shooting wide-open at f/5.6 (without the extender, the lens would be an f/4 of course). As robins in the midst of attacking prey can move with astonishing speed, I used a shutter speed of 1/2500. And, as almost always is best with animals, I was at or near ground level for these shots, to be on my subject's level. And the camera was on electronic shutter mode at 20 frames a second, to capture all of the action.

Unlike the worm in the first image, this one is a monster "nightcrawler". Here, the robin has just seized it and is working to tug the worm from the burrow. While such a task is fast and easy with a tiny worm, it is tougher when a big worm is involved. When under attack, the worm can bunch the powerful muscles that form rings down its body and plug itself into the burrow. Furthermore, worms are beset with rows of external setae - short stiff hairs - that can also help in holding it in place.

The robin tugs with all of its might. The bird is actually off of the ground and leaping/pulling backward. There were a few near extractions like this, and the worm would manage to tug itself further back into the hole. Then the robin would yank harder and in fairly short order it had won the battle.

The worm separates from the ground with great force, as if someone had let go of the other end of a Slinky. Its body coils sinuously as the pressure is instantly released, and the robin had it down the hatch shortly thereafter.

It should be noted that all of the large earthworms in this part of the world, insofar as I know, are night native. They are native to Europe and Asia and were brought over by accident in shipping material such as soils associated with nursery plants. It didn't take long for them to spread far and wide and increase enormously in abundance.

It didn't take long for the clever and adaptable American Robin to learn about worms and make them a large part of its diet.