The Cut-Throat Bird

On a hot, humid morning in late June, I climbed to the top of Sapsucker Ridge. As I followed the trail, I was serenaded by the singing of a hooded warbler, a black-throated green warbler, red-eyed vireos, and eastern towhees.

Suddenly, I heard harsh, loud, and repeated calling from an agitated brown and white rose-breasted grosbeak perched on a small tree beside the trail. She emitted what I later learned was the grosbeaks’ “squawk” alarm call. And squawk she did even as I continued on my way. Then she was joined by a second bird and they squawked back and forth. It was the nattily dressed black and white male sporting his rosy-red, V-shaped breast patch. He had flown in and perched high in a tree above the female. Not wanting to disturb them further, I walked on and still they called to each other, this time using their common metallic “chink” call.

I assumed that the pair was defending nestlings and that I had passed close to them since rose-breasted grosbeaks place their nests 10 to 15 feet up in the fork of a tree sometimes at the edge of a road and that section of our Sapsuker Ridge Trail is actually an old logging road.

Rose-breasted grosbeaks were familiar to early settlers since the first ones were collected before 1760 in Louisiana, presumably during migration because they don’t breed there. After several genus name changes, they were finally placed in the Pheuticus genus in 1850 which they share with the closely-related black-headed grosbeak of western North America. Pheuticus means “shy” or “to flee” in Greek and their species’ name ludoviciana is French for Louisiana. Their common name is “cut-throats” because of their rosy breasts.

These birds breed from southern Canada, the upper Mississippi Valley and the northeastern United States south through the Appalachian Mountains to northeastern Georgia. Here in Pennsylvania both atlasing breeding projects found that rose-breasted grosbeaks were widely distributed throughout much of the commonwealth but were not abundant in any one section. Because they were rarely found below 820 feet, they were more common across the northern third of Pennsylvania.

Their numbers also fluctuate from decade to decade. For instance, during Breeding Bird Surveys through the 1980s their numbers were high but decreased during the 1990s. And the Second Atlas of Breeding Birds in Pennsylvania, early in this century, found that rose-breasted grosbeaks were uncommon in the southern Ridge and Valley Province. Nicholas C. Bolgiano, who authored the account in the second atlas, suggested that because rose-breasted grosbeaks prefer to nest in young woodlands but not in highly fragmented forests, they may be finding it more difficult to find their preferred nesting habitats as our forests age.

On the other hand, older reports of nesting rose-breasted grosbeaks in Pennsylvania indicate a wide variety of nesting habitats, i.e. young to second-growth deciduous or mixed woodlands, thickets at the edge of roads or bordering streams or swamps, old orchards, shrubby fields, parks and gardens.

I did a short study of where I’ve seen rose-breasted grosbeaks on our mountaintop property in this century and discovered, to my surprise, almost everywhere including the building of a nest at the edge of the overgrown Far Field observed by one of our hunter friends—Tim Tyler—during spring gobbler season on May 12, 2007. Other areas were along Sapsucker Ridge Trail, in or near our three-acre deer exclosure, the Far Field Road, Greenbrier and Bird Count trails, and on Dogwood Knoll—all places above 820 feet. The only wet areas were a lower section of the exclosure and another encompassing a portion of Greenbrier Trail.

Rose-breasted grosbeaks return to Pennsylvania anywhere from the fourth week in April to the fourth week in May, although peak migration is the middle of May according to McWilliams and Brauning in The Birds of Pennsylvania. However, my earliest record for their return in this century is April 29, 2007, and most reliably the first week in May. By the second week in May, during International Migratory Bird Day, we always find rose-breasted grosbeaks, most notably the 12 that we counted in 2006 and the 7 in 2007.

I more often hear their brilliant songs, described by Roger Tory Peterson as robins that have taken voice lessons, than see rose-breasted grosbeaks since the males stay hidden in leafy treetops. But back in May 8, 2018, I encountered a continual chorus of rose-breasted grosbeaks, and after much persistence managed to get a good look at a male. Both sexes sing, but it is the male that first attracts a female by singing. When she approaches him, he rebuffs her for a day or two and then accepts her.

They appear to be monogamous during the nesting season and share in the building of a nest, which takes four to eight days, despite its flimsy construction. Composed of dried sticks and twigs, grasses, weed stems, decayed leaves or straw and lined with smaller twigs, rootlets or hair, if a person stands beneath the nest, the one to five, pale green to blue eggs spotted with reddish-brown or purple, can be seen through the nest lining. The grosbeaks choose any native tree or shrub species that hides the nest with dense foliage especially maple, birch, willow, or common alder, and in Cook Forest State Park, Hal Harrison, author of A Field Guide to Birds’ Nests, found a nest in rhododendron that was lined entirely with hemlock twigs. He concluded that “Apparently any small tree or shrub will do so long as it provides sufficient shelter.”

Rose-breasted grosbeaks also share nest egg incubation duties, the male relieving the female for one-third of the daylight hours, while the female is the sole night incubator. Both sing even on the nest, especially the male, which would seem to signal to nest predators, especially blue jays, common grackles, raccoons, red and gray squirrels, that there are eggs for the taking. It is likely, though, that the singing is to warn off other grosbeaks, male and female, from their immediate territory.

Most eggs in Pennsylvania nests are laid anywhere from May 15 until June 10 and incubation lasts 11 to 14 days. Once the eggs hatch, the parents share brooding the nestlings and keeping them fed, mostly with insect larvae and other insects, especially beetles (75%), and wild fruit, such as mulberries and June berries, as well as weed seeds—smartweed, pigweed, foxtail, and milkweed.  The adults like sunflower seeds at birdfeeders in spring and summer, peas, wheat, oats, tree flowers and buds and even cultivated fruits.

Our native shrub, the red-berried elder, which has berries in early June, is popular with rose-breasted grosbeaks for both nesting sites and food for their young. Back in June 10, 2007, when I approached a large red-berried elder on Ten Springs Trail, a male rose-breasted grosbeak landed on the shrub. I watched while he quickly consumed all the ripe berries on two umbels before flying off, giving me one of my closest and best looks at this beautiful bird.

It takes nestlings 9 to 12 days to mature enough to fledge, but the parents care for them another three weeks, and they stay together as a family until they migrate anywhere from late August to the second week in October in Pennsylvania. They also try to keep themselves and their grown offspring safe from Cooper’s hawks, sharp-shinned hawks, northern harriers, eastern screech-owls and short-eared owls, all of which prey on the adults and mature young.

During migration, rose-breasted grosbeaks, young and old, eat almost exclusively fruit. They overwinter in Central and South America, mainly in midland and highland forests and half-open habitats, as high as 11,000 feet in Colombia. In some areas the males are popular cage birds.

Although the overall population of rose-breasted grosbeaks has shown a slow decline from 1966 to 2015 according to the North American Breeding Bird Survey, they are not listed as Threatened or Endangered in any part of their range. Here in Pennsylvania the statewide population is estimated at 210,000 singing birds. So these handsome birds—glorious to look at and to hear—should be in the commonwealth for decades to come if we provide the kinds of habitats they favor.