Dear Bird Folks,

My neighbor just put out a birdhouse and told me that he is hoping that a pair of warblers will nest in it. I tried to explain to him that warblers do not use birdhouses. The best he could hope for would be bluebirds, swallows or some chickadees. He seemed certain that I was wrong and that he indeed would get some warblers. Who is right?

–Terry, Falmouth, MA

Not again, Terry,

Is the entire world arguing? Last week a husband and wife were squabbling over puffins and fish heads. The week before that I was dragged into a debate between hundreds of local citizens and the National Park Service over the subject of poisoning crows. Now you want me to mediate a dispute over a possible birdhouse tenant. Suddenly I’ve become Cape Cod’s answer to Judge Judy, only without the barbed wire attitude. I’ll admit that sometimes I have a bit of an attitude also, but my attitude is more like an old woolen blanket. There’s occasional irritation but plenty of warmth, too. At least that’s the way I see it.

Your neighbor is mostly wrong, but not completely. Out of the forty or so warblers that breed in the eastern half of North America, only one species will use a birdhouse. However, this one species, the Prothonotary Warbler, typically doesn’t breed this far north. In the past hundred years only one or two pairs of Prothonotory Warblers have successfully bred in Massachusetts. The last attempt that I am aware of took place in the town of Sharon back in 1982. However, that attempt was unsuccessful. Apparently, a neighborhood House Wren got wind of the new birds in the ‘hood and destroyed the nest. (For the record, House Wrens don’t necessarily hate Prothonotory Warblers. They hate everybody. Any cavity nesting bird that dares to build a nest within a House Wren’s territory will be treated equally.)

Prothonotary Warblers are most often found breeding in southern wetlands. An early name for this bird was “Golden Swamp Warbler.” The name was switched to “Prothonotary” because their color reminded some of the bright yellow robes worn by prothonotaries, papal clerks. Okay. Whatever. The point is the birds are yellow, but they are not a normal yellow. They are electric, knock-your-socks-off yellow. A Prothonotary Warbler makes a goldfinch look lackluster. The first time I saw a Prothonotary Warbler it actually made me speechless, which is not easy to do. The bird popped out of out thicket and disappeared two seconds later. I tried to call to my fellow birders but the words wouldn’t come out of my mouth. It was like trying to yell while dreaming. Finally, someone noticed that my eyes were bugging out of my head. That person knew right way that I had just seen a great bird, or perhaps a snake. I make the same face for either one.

Quiet wetlands and swamps are the preferred habits of Prothonotary Warblers. In years past the birds have nested almost exclusively in old woodpecker holes, but logging has made these locations increasingly difficult to find. Slowly the warblers have adjusted to using manmade birdhouses, especially if the birdhouses happen to be near water. Desperate birds will occasionally even nest near a backyard swimming pool, but only if the pool has a slide and fresh towels available. Prothonotary Warblers are particularly attracted to nest sites that are over water. It is thought the water provides the birds with protection from terrestrial predators. Also, the water is perfect breeding grounds for the delicious insects that the birds need for food. Nesting over water has a downside, however. If the baby birds leave the nest before they can fly, as they sometimes do, they could end up in the drink. Amazingly, the young warblers are born with some decent swimming skills and can usually make it to the nearest log before a snapper or a bullfrog has them for lunch.

An interesting historical and very true footnote has been attached to Prothonotary Warblers. Remember how excited I was the first time I spotted one of these birds? Well, it seems Alger Hiss, a novice birder and alleged Commie spy, was so thrilled upon seeing this bird that he bragged about it to another spy by the name of Whittaker Chambers. Years later, when Chambers ratted out Hiss in an effort to keep himself out of jail, he used this information to prove that he and Hiss were buds. The Prothonotary Warbler, along with lots of help from then Congressman Richard Nixon, ultimately got Alger Hiss sent to jail for perjury. The trial put Nixon in the national spotlight and helped advance his political career, which eventually saw him become president. In an effort to pay back the warbler, Nixon offered it a job on his staff, but the bird declined. In a short statement the warbler said it preferred to remain in its bug-infested swamp than to live in Washington. I don’t blame it.

I agree with you on this one, Terry. Most warblers will never use a birdhouse and the one species that does use one rarely ever nests this far north. The odds of your neighbor getting a warbler to use his box in Falmouth are pretty astronomical. It would be like winning the lottery or something even more unusual, like getting a smile out of Judge Judy.