Effects of subcutaneous transmitter implants on behavior, growth, energetics, and survival of common loon chicks

High rates of Common Loon (Gavia immer) chick mortality have been documented in Wisconsin, especially on acidic lakes, but causes and timing of chick mortality are poorly understood. We modified and evaluated a subcutaneous transmitter implant technique for Common Loon chicks using wild and captive reared chicks. Results indicated that behavior, growth, energy expenditure, and survival did not differ significantly between chicks marked with miniature transmitters (mass 0.76 g, representing <0.8% of body mass at hatching) and unmarked chicks.