Data from: Context-dependent effects of radio transmitter attachment on a small passerine

Biotelemetry devices provide unprecedented insights into the spatial behaviour and ecology of many animals. Quantifying the potential effects of attaching such devices to animals is essential, but certain effects may appear only in specific or particularly stressful contexts. Here we analyse the effects of radio transmitter attachment on great tits Parus major tagged over three environmentally dissimilar years, as part of a project studying social- and communication networks. When we radio-tagged birds before breeding, only those tagged in the coldest spring tended to be less likely to breed than control birds. Breeding probability was independent of relative transmitter weight (between 5 and 8% bodyweight). When we radio-tagged both parents during nestling provisioning (transmitter weight between 6 and 8%), tagged parents were more likely than control parents to desert their brood in two out of three years, while in the other year no tagged parents deserted. Tagged parents provisioning larger broods were most likely to desert, especially during lower average temperatures. Video analyses did not reveal any transmitter effects on provisioning behaviour of parents in the year with no desertion. We conclude that radio tagging before breeding did not lead to negative effects, regardless of transmitter weight, but that decisions about radio-tagging both parents during nestling provisioning need to be made with exceptional care, taking both environmental context and transmitter weight into account. Reporting results from long-term radio-tracking studies comprising several environmentally variable years is crucial to understand and predict potential transmitter effects and maximise the tremendous potential of biotelemetry.生物遥测（biotelemetry）设备可为解析众多动物的空间行为与生态学特征提供前所未有的研究视角。量化此类设备附着于动物体所可能产生的影响至关重要，但部分效应仅会在特定环境或极端应激条件下显现。本研究作为社交与通讯网络研究项目的一部分，对三年环境差异显著的野外环境中，无线电发射器（radio transmitter）附着对大山雀（Parus major）的影响展开分析。在繁殖前对大山雀进行无线电标记时，仅在最冷春季完成标记的个体，其繁殖概率较对照组个体更低；繁殖概率与发射器相对体重占比（5%~8%）并无关联。而在雏鸟育雏期对双亲均进行无线电标记时（发射器重量占比为6%~8%），三年中有两年的标记亲鸟弃巢率显著高于对照组亲鸟，剩余一年则无标记亲鸟出现弃巢行为；育雏规模更大的标记亲鸟弃巢概率最高，尤其在平均气温较低的环境中。在未出现弃巢行为的年份中，视频分析未发现发射器对亲鸟育雏行为产生任何影响。本研究得出结论：繁殖前进行无线电标记并不会产生负面影响，无论发射器重量占比如何；但在雏鸟育雏期对双亲进行无线电标记时，需格外谨慎，同时兼顾环境背景与发射器重量占比两个因素。披露涵盖多个环境差异年份的长期无线电追踪研究结果，对于理解、预测发射器潜在影响并最大化生物遥测技术的巨大应用潜力而言至关重要。