Mimus Polyglottus

Northern Mockingbird

While it may not be the Hatfields and McCoys, there is a family feud being waged in the Salem Woods. The Muscicapidae family is battling with the Mimidae clan.Northern Mockingbird (Mimus Polyglottus) While the Muscicapidae are holed up in the deep woods, the Mimidae are claiming the territory on the edges. The main weapon of this warfare is singing. TheMimidae bring incredible varitey and agility to hte conflict. While the Muscicapidae bring the secret weapon of self-harmonization to the most hauntingly beautiful singing you will ever hear. While there are only scattered reports of skirmishes, when they occur, they are a delight to the ear. These two bird clans easily constitute the most accomplished songsters in  North America. Only individual taste can decide which is superior.

What the Muscicapidae lack in repertoire and technical finesse is compensated by their remarkable ability to self-harmonize. The structure of their vocal organ (or syrinx) is bony and located at the lower end of the trachea near a resonating air sac, much different from our larynx located at the top of the trachea with its vocal chords. These differences allow birds to produce two notes simultaneously. Slowing the songs of the Muscicapidae reveals this fact, and hearing it in the field is an experience not to be missed.. Frank Chapman described the Muscicapidae as "A peerless trio of songsters. The Veery's (Catharus fuscencens) mysterious voice vibrates through the air pulsating circles of song like the strains of an Aeolian harp. The Wood Thrush's (Hylocichla mustelina) notes are ringing and bell-like; he sounds the matins and vespers chimes of day, while the Hermit Thrush's (Catharus guttatus) hymn echoes through the swelling tones of an organ in some vast cathedral."

The Mimidaie are not true mimics, as there is no evidence that their intent is to deceive. Rather, they accomplish remarkable vocal appropriation. Northern Mochingbirds (Mimus polyglottus) have been known to copy dogs barking, the screeching of machinery, even human whistling. The Mimidae seem just to love singing, and sing for love since unmated males sing more songs and more often. Male Brown Thrashers (Toxostoma rufum) have the largest repertoire of all North American songbirds with over 1100 song types documented and an estimated repertoire of over 3000 songs! Often these mimics are difficlt to identify by their songs since thay can be near-perfect imitations (the first Tufted Titmouse I indentified "by ear" was a conspicuously perched Mockingbird). Gray Catbirds (Dumtella carolinenses) derive their name from the "meow's" that often punctuate their copycat calls. Aside from this diagnostic song, the trick to identification of the Mimidae is the consistency of their repetitions. It takes a trained ear, but once you know the sound of a Mimidae voice (even when it is singing someone else's song) count the number of times the borrowed tune is repeated. Catbirds generally do not repeat, Thrashers usually repeat tunes twice and Mockingbirds sing it thrice, and often string four or five tunes together in rapid succession. As you learn to identify more bird songs, one of the fun occurences of each spring is listening to the calls of exotic species singing in the Salem Woods from the throat of Mockers recently migrated from tropical habitats.

While all these species are migratory, it is not terribly uncommon to find an overwintering Hermit Thrush or Catbird, especially within the immediate vicinity of open (i.e. unfrozen) water. Veeries will expand their range in the absence of Hermit Thrushes and Wood Thrushes expand where Veeries are absent. Despite their name, Northern Mockingbirds were common only as far as Virginia at the turn of the century. Fortunatelly, all six of these marvelous songsters occur with regularity in Salem Woods. In fact, it is one of the few spots in this area where Brown Thrashers abound. So give your ears a treat, get out to Salem Woods, and listen to the daily concert.


P.S. Should you see a Hermit Thrush, don't be too quick to check it off the list and move on. Spend some time observing its behavior. Hermit Thrushes are on of a number of species that engage in a practice known as anting. They will place ants on themselves or in other ways encourage ants to crawl onto them. Scientists ae unsure why they do this. The most widely accepted theory is that the secretions of ants somehow aids the bird, perhaps they are insecticidal, miticidal, fungicidal, or bactericidal. It is also possible that they supplement the bird's preen oil. If you see this behavior, take note of wht the bird was doing before and does after, where it is, what kind of ants, etc. This information from amateurs can be of great value to the scientific community.