Thrushes

Because species of thrushes are among the more familiar and well appreciated native birds, they are an important component of the aesthetic environment. This is true of both natural habitats and managed habitats, such as gardens and parks. As such, the activities and songs of a number of species of thrushes provide people with a meaningful link to the more natural aspects of the human experience.

The European blackbird and European song thrush (Turdus philomelos) were introduced to New Zealand and

Australia by British colonists. This was done as part of a larger attempt to make their new, foreign surroundings more familiar in the context of west European culture.

In some places, populations of thrushes have suffered badly as a result of poisoning caused by their exposure to insecticides used in agriculture or for other purposes. For example, during the 1950s and 1960s, populations of American robins declined greatly in places where the insecticide DDT was used to kill the beetle vectors that were spreading Dutch elm disease. The latter is an introduced pathogen that is still killing native elm trees over large areas, including large and valuable trees in cities and suburbs. The disappearance of robins and their prominent, melodious songs was an important component of the so-called "silent spring" that became a metaphor for the ecological damage associated with some types of pesticide uses. As such, the health of robin populations became a very important indicator of the broader health of the urban and suburban environment.

Thrushes seen only occasionally in North America include

• White-throated robin (Turdus assimillis). A southwestern stray. Normally a resident of the tropical mountains, this bird has been seen in southern Texas during particularly harsh winters.
• Clay-colored robin (Turdus grayi). A southwestern stray. Normally resides from eastern Mexico to northern Columbia, this bird has become a frequent visitor to southern Texas (especially in winter) in recent years.
• Redwing (Turdus illacus). An eastern stray. Normally residing in Europe and northern Asia, this bird has been observed several times in North America (mostly in winter).
• Dusky thrush (Turdus naumanni). An Alaskan stray. Normally a resident of Asia, this bird has been observed in Alaska on several occasions.
• Eyebrowed thrush (Turdus obscurus). An Alaskan stray. Native of Asia. Seen as a rare migrant in the western Aleutian Islands. Has also been observed on the Pribilofs, St. Lawrence Island, and the Alaskan mainland.
• Fieldfare (Turdus pilaris). An eastern stray. Common in Europe and parts of northern Asia, this bird is sometimes seen in eastern Canada and the northeastern United States. There have also been sightings in Alaska.
• Red-legged thrush (Turdus plumbeus). A native of the West Indies, this bird was once seen in Miami, Florida.
• Rufous-backed robin (Turdus rufopalliatus). A southwestern stray. A resident of Mexico, this bird occasionally strays north to southern Arizona. Sightings have also occurred in Texas, New Mexico, and California.