Published Date Written by David EastmanAccording to the NH Bird Records, a summer tanager was photographed in 2011 coming to a feeder in Windham. This is amazing, as the last time I saw this bird was at the Darden Scout Reservation in Virginia during my youth. ASNH says there are perhaps a dozen previous records of this rare southern bird, all of which were "spring overshoots." This and the scarlet tanager are the only two members of these tropical species that frequent the east coast of the United States.
The eye-catching scarlet tanager we usually see is certainly one of the most gorgeous birds in North America. The male with his striking red and black plumage can really stand out against the lush forest leaves of early summer, almost illuminating an oak stand's cool green colors with this contrast. It has been said that the tanager is the fieriest thing that flies; to see one can be glory enough for one day.
Scarlet tanagers are quite common in our northern woods, but may be heard more than seen. You may think you are hearing a robin calling rather hoarsely, as if it had acquired a sore throat. The tanager makes a "Chip-chur" sound far more often than its "querrity-querrity-querrity" call. Since the male is so lavishly colored compared to his yellowish olive-green female, he possesses some interesting ventriloquial power to lure you away from the nest. Try to locate a singing scarlet tanager on an early summer day and you'll find yourself moving from one tree to another--while the male trills away in the full canopy overhead. It's a good lesson in birding, and an amusing game witnessing the skill the male displays to protect the nest location.
He must warn other male tanagers away--that this is his territory, without giving away the presence of his concealed mate brooding on the nest nearby and caring for their young. This ball of fire seems to know how conspicuous his plumage is. Once you learn the scarlet tanager's call, you may wind up more emotionally frustrated than wise, trying to observe him in the dense hardwood foliage.
This bird is a superb caterpillar hunter. The tanager's diet consists of tree-eating insects up to an 80 percent level. His motions are leisurely, but he eats insect life voraciously. Tanagers destroy not only hairless larvae of many species, but also hairy ones such as the gypsy moth and forest tent caterpillar as well.
A scarlet tanager may land where tent caterpillars are defoliating a young tree, and remain there until enormous numbers of the recently hatched caterpillars are devoured. One bird ate 600 tent caterpillars in l5 minutes. It has been estimated that two scarlet tanagers could destroy over 14,000 gypsy moth caterpillars in a week's time.
Oak-pine-hemlock forests are where you'll find this tropical visitor and it does its job well there. Only once in a decade did the gypsy moth larvae get ahead on a massive scale, making the hillsides of New England look like a late fall landscape. Not many know they could have been thankful to the scarlet tanager for all the years in between. But, why we have not had a severe gypsy moth outbreak since the eighties is open to several theories, perhaps including that of an introduced fungus that sprang up many years late.
Forest scientists were also speculating that these terrible outbreaks may have been connected to red oak acorn crop failures in the past. When not enough of this important mast was produced, the mice died off that were very likely eating quite a bit of the gypsy moth cocoons. If the deer mouse population crashed, there wasn't control over the erupting gypsy moths in their pupa stage.
As helpful as beautiful scarlet tanagers are in the orchard and forest, they can be lured to the feeding station if you provide fruit for them. Sliced apples, oranges, bananas, raisins, and bakery crumbs will work. As summer wanes, the scarlet tanagers' diet includes the wild fruits of serviceberry, huckleberry, mulberry, sumac, blackberry, blueberry, and the elder. Dogwoods and wild cherries, too, will be consumed along with the bayberry along seacoast migration routes.
This colorful tanager leaves us in October for the Andes, where it overwinters. The tanager family likes it warm and is represented by 236 species in the Western hemisphere. But, it is the scarlet tanager which makes the longest flight of the tanager species that grace us each spring.
The scarlet tanager certainly is a first class pest destroyer, but is only one of the neo-tropical migrants we should be more concerned with. The now-classic program, "Partners in Flight" seeks to unify all agencies, national and international, to be more efficiently concerned with the Southern hemisphere birds that visit us for four or five months of the year.