Editor’s note: Jim Wright checked in with the Office of Law Enforcement, U.S. Fish and Wildlife Service, to report on his actions mentioned in this column. They informed him that the agency does not fine anyone who unknowingly destroys these eggs and self-reports.

   I must make a terrible confession. I ask only for your advice and possibly your forgiveness. 

    While vacationing last month, I noticed a phoebe nest on the rental home’s porch. When the female phoebe took a break from her incubation duties, I stood on a chair and took a cellphone photo.  

    When I examined my snapshot, I saw a nest with five jelly-bean-size eggs. Three eggs had dark brown speckles. Two were glossy white.

   Uh-oh: A brown-headed cowbird had laid three eggs and split, leaving the phoebe to unwittingly incubate the eggs and raise the babies. Cowbirds are known as brood parasites – typically insects, birds or fish that rely on others to rear their young.

   Cowbird eggs are generally larger than the other birds' and hatch sooner, giving the cowbird nestlings a better chance of surviving. 

   I emailed a naturalist friend for advice. 

  He replied: “Can you remove the cowbird eggs? A song sparrow in our garden has been raising a young cowbird. It breaks my heart to see all her hard work going into such an unworthy parasite – a pseudo-offspring with no redeeming qualities. Am I being too harsh?”

   The next time the phoebe left the nest, I took his advice, then waited to see what happened when Momma returned. Five minutes later the phoebe returned and incubated the eggs once more. If she noticed three eggs were missing, she gave no indication. I breathed a sigh of relief.

   Then I went online and found an Audubon magazine article on the subject. It advised that I should have left the eggs alone for several reasons. Foremost, cowbirds are protected under the Migratory Bird Treaty Act, and taking their eggs without a permit is therefore illegal.

   What’s more, the phoebe might have abandoned her eggs after realizing the others were gone. I dodged that bullet.

   But most surprising, I learned that cowbirds can exhibit Mafia-like retaliatory behavior when another bird ejects the parasitic eggs. The cowbirds will destroy the host bird’s eggs as payback – and as a warning not to do it again.

   Jeffrey Hoover of the Illinois Natural History Survey and a colleague did research that showed that cowbirds retaliate more than half the time when their eggs are ejected from other nests. 

  “I think that cowbirds are fascinating as opposed to evil,” Hoover says. “They’re doing what they have evolved to do. The main reason they’re a conservation issue in some circumstances is because humans have altered the landscape and flora and fauna so as to favor cowbirds and to the detriment of hosts.”

  Fortunately, I saw no Mafia-like cowbird behavior that weekend, and the phoebe family is better off because of my actions. What’s more, there are now three fewer future cowbirds to exhibit Mafia-like behavior of their own.

   Nonetheless, what I did was against the law, and I was wrong. Wasn’t I?