Avian tracking studies have proliferated due to the miniaturization of tags and the opportunities for massive data collection facilitated by an extensive satellite and cellular infrastructure. However, assessments of the effects of tags on the behaviour and survival of birds are rarely conducted and disseminated – raising animal welfare concerns, risking project failure, and hindering the optimization of tagging methods within the ornithological community. Here we quantified the effects of tags on banded dotterels (Anarhynchus bicinctus) – a threatened small-bodied (median 59 g) partially migratory shorebird native to New Zealand and a priority species for conservation planning on Austral flyways. We deployed ten 1.2 g archival GPS tags and ten 1.8–2 g Argos satellite tags on breeding dotterels in Kaikōura, New Zealand. Including leg bands and silicone-tubing leg-loop harness, tag deployments constituted 2.7–4.3% of an average individual’s mass (or 1.9–3.4% based on the tag alone). Both tag types documented the curiously mixed winter strategies characteristic of banded dotterels: migrants flew north to the upper North Island or south to inland Canterbury, while other individuals stayed resident in Kaikōura. Compared to a control group of 74 untagged dotterels, neither tag technology had adverse effects on subsequent breeding outcomes, annual apparent survival, behaviour, or body condition, but Argos satellite tags provided data over a longer period than archival GPS tags. One possible reason for the absence of adverse effects could be that banded dotterels (and other Charadriinae species) primarily rely on ground-based locomotion, characterized mainly by walking and running – movements that are less hindered by the added mass of auxiliary attachments. Our findings support the ‘3% rule’ (i.e., using tag weight alone as a guideline), but we suggest that tag deployment limits could be refined by considering both the species’ ability to carry additional weight and its primary mode of locomotion.