A Test of Radio-Transmitter Effects on Parental Investment and Productivity in the Northern Cardinal

[摘要] Abstract. Researchers often attach radio transmitters and other devices to free-living birds without a clear understanding of the possible consequences for their study organisms or their data. Although transmitters may affect parental investment (nest defense and offspring provisioning), this possibility has received little attention. We tested this hypothesis by placing mock radio transmitters on male Northern Cardinals (Cardinalis cardinalis) and comparing their behavior to that of uncaptured birds and procedural controls. Birds with transmitters defended their nests less vigorously than did uncaptured birds but did not modify their provisioning effort. This behavioral modification appears to have ultimately influenced predation rates, as nests of birds with transmitters had lower daily survival rates and were less likely to fledge offspring. Control birds that were captured, handled, and bled had intermediate levels of nest defense and productivity that were statistically indistinguishable from those o...

[学科分类] 动物科学

[关键词] blood sampling;Cardinalis cardinalis;mate conflict;nest defense;offspring provisioning;reproduction;telemetry