An important assumption of telemetry studies is that radiomarking does not negatively affect study animals. To test this assumption for mourning doves (Zenaida macroura), we evaluated whether subcutaneous transmitter implants (STI) would affect bird weight in cage studies and hunting mortality in field studies. At three weeks post-implantation, caged adult birds in the sham surgery and control groups gained and STI birds lost weight. Males gained and females lost weight. When percent weight change (PWC) for caged adult and juveniles were pooled the trends were similar, suggesting a STI treatment effect. In the field study, 16.3% of observed mortalities of STI birds during July–November 1998–2000 occurred during the first 3 days post-release. The overall 45-day summer period survival rate was relatively high, 0.9446 (95% CI = 0.8907–0.9986), when birds were entered into the population at-risk on the fourth day post-release. Although most observed mortalities were hunting-related (62.7%), similar direct recovery rates (P = 0.186) for STI (14.7%) and leg-banded birds (9.2%) suggests that implanted radios did not increase a bird's vulnerability to hunting mortality in the year of marking. However, the difference between the direct recovery rates of the 2 cohorts may be large enough to be biologically significant. Further research is needed to determine whether STI birds are especially susceptible to hunting mortality.
subcutaneous transmitter implant