EFFECTS OF RADIO TRANSMITTERS ON MIGRATING WOOD THRUSHES

摘要: --We quantified the effects of radio transmitters on Wood Thrushes (Hylocichla mustelina) using 4 yr banding and telemetry data from Piedmont National Wildlife Refuge, Georgia. Flight performance models suggest that 1.6-g transmitter shortens migratory range wood thrushes by only 60 km, estimated is adequate to accomplish migration even with limited fat stores. We used two strengths line, 5and 9kg test-strength braided Dacron, attach thigh-harness method. recaptured 13 returning radio-marked thrushes, seven which were still marked. Six birds marked 5-kg test harnesses lost their within 1 while all six 9-kg attached up 21 mo later. Radio-marking did not reduce return rates adults immatures, cause lose more mass than banded-only birds. can successfully carry a during no detectable negative effects. recommend continued use method, but we encourage cotton line. EFECTO DE LOS RADIOTRANSMISORES EN HYLOC/CHLA MUSTELINA MIGRANTES Sinopsis.--Cuantificamos el efecto de los radiotransmisores en Hylocichla mustelina utilizando aftos datos anillaje y telemetria del Refugio Vida Silvestre Nacional Piedmont, Los modelos desempefio vuelo sugieren que reducen alcance migratorio esta especie por tan solo estimado es adecuado para conseguir la migraci6n inclusive con falta reservas grasa. Utilizamos lineas dacr6n entrelazadas probadas resistencia dos potencias linea, 5-y 9-kg, ajustar m•todo arnfs muslo. Recapturamos aves marcadas radiotransmisores, siete las cuales estaban todav/a marcadas. Seis arn6s prueba Current address: Institute Ecology, University Georgia, Athens, Georgia 30602.