Another Blue Mood?

By Kenneth Turner Blackshaw

Several people requested I write about this bird. I hadn’t been planning on it, but heck; a request is a request -- so here goes. This is a single bird that made quite a splash on our island this spring – for two reasons. First it is a bird rarely seen here and second it was a very visible bird – many non-birders spotted it and wondered what it was – and oh, a third reason. It stayed around for weeks.

Like the Indigo Bunting, this bird is also blue, but a different sort of blue, more of a purply color -- slightly larger, not robin-sized though, and a bit chunkier. The beak is huge, like a cardinal’s and also is responsible for its name – grosbeak. Its color is responsible for the other part of the name, for it is a Blue Grosbeak.

Looking in the bird book, you might think this would be a difficult bird to identify, since ostensibly it could be confused with the Indigo Bunting. But in practice, its size and deliberate behavior set it apart. Also, it is a different sort of blue. Actually, unless you see it in direct sunlight, it appears black, looking more like a cowbird.

The other identification points are the two rusty bars on the wing that set the bird easily apart, in good light. Of course we are describing the male. The female is mostly brown all over, but with the same shape as the male. Identifying a solo female Blue Grosbeak is a challenge. There are too many other brown birds of this size with which to confuse it. So, most of the records of this species here on the island are for males.

Now, birders poured out to see this bird because it is rare here. It was not in Edith Folger Andrews’ 1948 book at all. However in recent years, it has passed the threshold of five records and it is considered ‘rare’ rather than ‘accidental’. Blue Grosbeaks don’t normally come further north than southern New Jersey. The bird that arrived here on April 17th was what birders refer to as an ‘overshoot’.

Sometimes in the spring, when there are strong southwesterly winds, night-flying migrants travel much further than planned. In the morning, they find themselves in areas they never expected to be. Frequently these overshoots are birds making their first trip north – and their last, because a bird out of its normal habitat is an easy target for a predator.

So, on the morning of April 17th, an alert rang out across Nantucket’s birding community and soon, a motley crew of people gathered out on the Milestone Road with binoculars, telescopes, and cameras. Not only did we have a rare bird, a ‘life’ bird for many of the group, but also we had a bird that was hard to ignore. This particular grosbeak liked the grassy berm of the ‘Sconset Road. It would hop along in the grass, feeding, and then occasionally make an almost suicidal flight across to the other side. This was very alarming to the birders because it seemed to wait until there was a huge dump truck or cement mixer hurtling towards it before making a low, rather flitting sort of journey across to the other side. One of the reasons many birders hurried out to see the bird on that first Saturday morning was that we doubted it would survive very long, behaving like such a daredevil.

But survive it did, for at least three weeks. We kept thinking, we’d either see the bird alive, or find it squashed on the roadside. This Blue Grosbeak developed a long, linear territory that stretched from the Rotary out past the Airport cutoff. Folks who had no bird knowledge or particular interest at all would e-mail me, or call me on the radio (another hobby) and tell me about this blue bird they saw, often just a few feet ahead of their front bumper as he sallied across the road – very dramatic.

It was also interesting that although the bird was seen a lot, it didn’t appear to be setting up territory as an active breeding male should have been at this time of year. It wasn’t heard to sing. So, this is just more evidence that we had a bird making his first journey back to where he was hatched the preceding year, and somehow found himself up in Never Never Land, where very few of his kind ever arrive.

Blue Grosbeaks of breeding age normally get right to it in the spring. This species normally raises two broods, so they start early in May and don’t finish until early September. It’s interesting that some species have this high level of reproduction and others don’t.

But after May 6th it disappeared. Did it finally lose its contest with large vehicles or head to less conspicuous climes? Since then another(?) Blue Grosbeak has been seen in Polpis. Could there be two? The birders will just have to guess. We don’t get them every year, but they’re becoming more frequent, another symptom of global warming about which our government seems unconvinced. Perhaps if there was a conservationist in the Cabinet …?

George C. West creates illustrations for these articles.

The Maria Mitchell Association sponsors bird walks every Saturday, leaving at 8 a.m. from the Hinchman House on at the corner of Milk and Vestal St. There is a fee. Call 228-9198 for more information.

To hear about rare birds, or to leave a bird report call the Massachusetts Audubon hot line at 888-224-6444, option 4.