January 23, 2023
The rain has changed Little Lake Valley in many ways, and it is now the middle of winter. The days are still shorter (though each day is incrementally longer) and we have especially cold mornings with a few hours of warm sunshine on the days it hasn’t been raining. Walking out into the valley it is astounding how many American Robins, Turdus migratorius, are hopping around the puddles and grass. As I observe them, I notice how focused and intent they are on what they are doing, which is hunting for food. They are looking for worms as everyone knows but Robins are not only targeting worms. They eat lots of invertebrates such as slugs, snails, millipedes, termites, grubs (insect larvae), spiders, and true bugs. They have also been reported eating small snakes and shrews. Most of their diet (60%) is made up of fruit and berries such as Hawthorne and Chokecherry. Just last week before the last rain, my yard and garden were full of American Robins noisily finishing off the remaining Madrone berries and by the end of the day the ground was littered with the husks of the bright orange-red madrone berries. There has been some research in the past that suggested that American Robins use their sense of hearing to find worms and other invertebrates, and they do appear to be listening. However, it is now believed that they depend more on their eyesight and visual cues of any movement and maybe only 10% of the time using their ears.
The American Robin can be found throughout Canada and the United States except Hawaii. They also occupy regions of Mexico and Central America. Robins, considered a medium-sized bird, are 8 to 11 inches in length and their wingspan is 12 to 16 inches. Robins are frequently used as a reference point when identifying other birds. Many field guides such as the birding app Merlin, pose the question, “Is it smaller or larger than a Robin?” when narrowing down identification possibilities for the birder. The males have a rich reddish-orange chest and a dark gray head. The back and wings are brown. The females have the same color scheme but are duller. Juveniles have dark spotting on the chest. All robins have a large broken white eye ring.
The name Robin came from the French diminutive word for Robert and was used in England for a common bird of gardens that everyone loves. Like the American Robin, it has an orange chest. This ‘European Robin’ (Erithacus rubecula) is a much smaller bird in a completely different family than the American Robin. The American Robin is in the Thrush family, which includes other melodic singers such as the Hermit and Swainson’s Thrush. The song of the robin is one of our first spring bird songs, singing before the sun is up and even after sunset.
American Robins are migratory birds with some populations moving south to north and back again, but some robins become residents of one place depending on conditions. This explains why in the summer we have robins but they are spread out and don’t seem to be in high numbers, but in fall and winter their numbers swell into the thousands as birds from Canada and northern USA fly in to winter in our much warmer valley.
Robins are common nesters in our region, and I have been surprised by the solid construction and size of the nests I have found in my fruit trees and thick trumpet vine bushes. They are early nesters and can have 3 clutches in one breeding season (which is why they build such a sturdy nest). The nest is mostly built by the female bird and she begins building from the ‘inside out’ with soft dead grass and small twigs. Then other materials such as feathers, rootlets, moss, and even paper are added and reinforced with soft mud. This mud is gathered from earthworm castings and acts as an adhesive, adding to the stability of the heavy, very sturdy structure that can withstand the elements and multiple clutches of birds. The final touch is the soft fine grass lining the cup. Robin nests can be 6 to 8 inches across and 3 to 6 inches high. Even though they can have so many young, it is estimated that only one half of robins alive in one year make it to the next.
American Robin populations are not in peril as they have adapted to humans better than some other species. They provide benefits such as seed dispersal, control of some insect populations, and are prey for many predators such as Peregrine Falcons and other raptors. Before the U.S. Migratory Bird Protection Act in 1918, robins were regularly hunted and eaten by humans in the U.S. Because they forage on the ground on lawns and agricultural fields, they are susceptible to pesticide and herbicide poisoning. Neonicotinoids, chlorpyrifos, and glyphosate, found in Round-up, not only affect their health but kill the earthworms and other invertebrates they depend on for almost half their sustenance.
American Robins are beautiful and easy to find in the Willits Valley. I hope that they will be around for many generations to come.