This photo is worth at least 1,000 words: The first and only time Bill Danielson witnessed a ‘parasitic’ cowbird being fed by its ‘adoptive parent’ | Home-garden

This photo is worth at least 1,000 words: The first and only time Bill Danielson witnessed a 'parasitic' cowbird being fed by its 'adoptive parent' | Home-garden


We’ve all heard the phrase, “A picture is worth a thousand words.” This suggests that if you can simply see something, then you can understand the situation perfectly. In my line of work, however, this is often a gross underestimate of the power of a photo.

Where can you find the gray hairstreak? Look for this beautiful, little butterfly among the clover

In many cases, one of my photos might be worth several thousand words because the photo needs to be explained in several different ways. So I am going to attempt to explain the significance of this week’s photo in 1,000 words or less. Here goes.

It was Aug. 22 and I was returning to my house after another successful visit to my Thinking Chair. During an epic 3-hour session that started at 5:55 a.m., I had managed to accomplish a feat that I had initially thought to be impossible. I had tied the seemingly unbreakable record of observing 64 species in my yard in the month of August. I was absolutely giddy with self-satisfaction.

It was no accident that I had tied the “unbreakable” record. I had certainly put in the time by making 13 visits to the Thinking Chair in 22 days. But time alone is not always going to produce results. You also need a lot of luck and possibly even a smidgen of divine intervention. For this, I rely upon Nikonus and Iso, the photo gods.

Nikonus is the god of timing and he is rather brutal. He will present you with a species, but you have to be quick enough to see it. Iso is the goddess of color and light. Far more compassionate, she dictates the conditions necessary for good photography. Together, they determine if I can take a photograph or not.

So there I was, walking out onto my deck after reaching an amazing milestone when all of a sudden I caught sight of a bird that simply didn’t fit the setting. From the far railing, this bird flies up and I am struck with the simple impression of a gray bird with long wings and a relatively short tail. I would have dismissed it as a mourning dove, but the tail was wrong.

My birder’s brain sent back a reactionary identification after this split second and imperfect view, but I needed to see the bird again to confirm. Nikonus had offered up a challenge, I had been in the right place at the right time and he was so pleased that he gave me an extra moment.

The bird was up in my cottonwood tree and I was able to find it and confirm my initial identification. It was a brown-headed cowbird (Molothrus ater) and it was the species that set a new record. I was elated, but there was also a note of disappointment because of the nature of the species in question. The brown-headed cowbird is a species that is described as a “nest parasite.” This means that female cowbirds will find the nests of other birds and then lay one of their own eggs into the nest of the unfortunate host. If things work out, then the host birds will raise the baby cowbirds as their own. At no point will cowbirds raise their own offspring.

This is often devastating to the host species for two reasons. First, the host loses an egg when the cowbird makes a deposit because the female will physically remove it. Second, the cowbird chick is so much larger than the host species that it crowds out the remaining chicks (causing their deaths) and occupies all of the feeding efforts of the adults. The eastern phoebes that nest by my front door are plagued by cowbirds and sometimes there are very few phoebe chicks to show for months of effort by the parent birds.

So, while delighted that I had broken the unbreakable record, I was also a little disappointed by the identity of the species involved. I went into the house, put down some of my gear and then made the decision to go back out onto the deck to get a photo that would prove that I had seen this particular species at this particular time. This is when the photo gods decided to reward me for my dedication. The cowbird flew down into a large bush just behind my house and perched on an exposed branch. I focused, snapped a few photos and grumbled slightly while doing it. Then I saw the cowbird’s wings begin to flutter in a manner that has a distinct and unmistakable meaning, “Feed me.”

This could only mean that the cowbird’s host parent was nearby and the cowbird expected an imminent delivery of food. Stunned, I kept my eyes peeled on the young bird in anticipation of the arrival of the parent, and I was rewarded for my dedication when a female Common Yellowthroat (Geothlypis trichas) appeared with a green insect in her beak. She quickly shoved the food into the gaping mouth of the young cowbird and then zipped off to find yet another morsel for “her” baby.

In all of my years of wildlife observation, this was the first (and only) time that I had ever witnessed a parasitized species feeding the offspring of a nest parasite. I had not seen a cowbird in my yard in weeks and the only reason that I saw this particular bird in it that particular moment was the female yellowthroat had wandered up out of the meadow into the tall grasses and forbs of my backyard in search of food for the behemoth that she was trying to feed. The cowbird was following its mother and disappeared soon after. Had I not been in that particular place at that particular time, I would have been totally unaware of the entire event.

As summer comes to a close, our backyard birds are quiet as they prepare for migration or hunker down for winter

Well, that was 870 words and I have only managed to scratch the surface of this story. Unanswered questions are: How did it come to pass that cowbirds developed this breeding strategy? Why do other birds fall for this trick? Are there any species that are not as easily fooled? When did I first detect the presence of Nikonus and Iso? These are all questions that would require other columns to answer, but I am out of space for this week.

I end with the same message that I try to deliver every week. Keep your eyes open and make sure you look out a window from time to time. Amazing things are happening out in nature every day and sometimes they are happening in your very own backyard. If you tear your eyes away from the myriad screens that surround you every day and take a peek outside, then perhaps Nikonus and Iso with reward you with something amazing to see.

Bill Danielson has been a professional writer and nature photographer for 26 years.  He has worked for the National Park Service, the U.S. Forest Service, the Nature Conservancy and the Massachusetts State Parks and has taught biology and physics at Pittsfield High School for 20 years. For more information, visit his website at