Damage to Loblolly Pine by Winter Roosting Blackbirds and Starlings

Roosting blackbirds and starlings (Sturnus vulgaris) caused extensive damage to a 4-hectare, 14-year old loblally pine (Pinus taeda) stand near Shannon, Georgia. Over a 4-year period, a one million-bird roosting population killed 96 percent of the pines on a 2-hectare area, which resulted in a loss of $51.80 per hectare. Black and white panchromatic and infrared film exposed from 150 to 250 meters altitude effectively delineated areas of tree stress and mortality. Approximately 1 hectare of the roost site treated with surfactant solution at the rate of 61.2 liters per hectare during a test in 1969 showed no adverse effect on roost vegetation.