Effects of Implanted Radiotransmitters on Captive Mourning Doves

Abstract

Previous mourning dove (Zenaida macroura) telemetry studies using transmitter glue attachment have found the technique to be relatively short term (<10 weeks), and that transmitter harnesses possibly have deleterious effects on doves. To improve attachment methods, we developed and refined surgical techniques for implanting subcutaneous and intra-abdominal radiotransmitters with external whip antennas in mourning doves, and we determined physiological and pathological responses to the transmitter implants. We used a captive colony of 200 wild-trapped mourning doves to develop and test procedures for subcutaneous implants (SC1), subcutaneous surgeries without implants (SC2), intra-abdominal implants (IA1), intra-abdominal sur- geries without implants (IA2), and a control group without surgeries or implants (CNT); 20 males and 20 females were assigned to each experimental group. Surgeries for IA1 took less time (3.58 t 0.17 min; i? + SE; P < 0.001) than SC1 surgeries (4.36 ? 0.12 min). Heterophil:lymphocyte ratios showed that IA1 and IA2 doves had higher (P = 0.024) posttreatment changes compared with SC1, SC2, or CNT groups. At 4-6 days postsurgery, 153 of 160 (95.6%) doves with surgical treatments showed closed or healed surgical sites with no complications. At 14 days posttreatment, 34 (87%) SC1 implants were located in the thoracic inlet. Gross necropsy findings at 10 weeks postsurgery found that 36 of 39 (92%) SC1 and 36 of 39 (92%) IA1 implants showed little or no tissue response to the implants. Functioning transmitters began failing 2 weeks posttreat- ment, and 85% were not working at 10 weeks posttreatment. Our data suggest subcutaneous implants with external antennas were a better alternative compared to intra-abdominal implants with external antennas, but further testing is needed to compare subcutaneous implants to conventional attachment techniques.