Scarlet Tanager

Scarlet Tanagers tend to forage high in the canopy on caterpillars and other large insects, and during the nesting season are more often heard than seen. Their song is often described as resembling “a robin with a cold,” and is uttered by both males and females, sometimes with the female following the male’s song immediately with her own. Also distinctive is their “chip-burr” call – another indication that there is a red or green bird above you in the canopy where you can’t see it!

Scarlet Tanagers can be susceptible to inclement weather. This usually creates problems during unusually cold and/or wet periods after spring arrival in mid-May, sometimes leading to birds visiting feeders because insects are less active. If adverse conditions persist, there can be significant mortality. Such an event occurred in late May of 1974, when observers reported dead or moribund tanagers along roadsides across central New Hampshire. Enough birds died that the population dropped noticeably and remained low for several years. Although numbers rebounded, the 1980s saw the beginning of a longer and more sustained decline that continues to the present.

The decline is believed to be due largely to habitat loss: tanagers are birds of the deep forest and often disappear from the smaller woodlots that are left behind when land is converted to homes, businesses, and farmland. Some estimates place the minimum forest size needed for tanagers at 40 acres. In smaller forest patches, tanagers may be more susceptible to both nest predation and nest parasitism (by Brown-headed Cowbirds), and thus produce fewer young in a breeding season. Even in larger forest blocks, suburban sprawl continues to eat away at the edges. Like many of our other declining forest birds, Scarlet Tanagers spend the winter at mid-elevations in the Andes of South America, an area at increasing risk from habitat loss due to expanding agriculture and human populations.

Male Scarlet Tanagers are only red for half the year. After breeding they gradually replace all their body feathers with an olive green (hence the “olivacea” in the scientific name). They keep their black wings and tail however, which allows them to be distinguished from similarly-plumaged females – whose wings and tails are grayish-brown. In late winter, while still in South America, the males molt again to replace the green with scarlet and are again ready to wow observers in the north after our long dreary winters.