Short-term tracking tag attachment disrupts chick provisioning by Atlantic Puffins Fratercula arctica and Razorbills Alca torda

Abstract

ABSTRACTCapsuleAtlantic Puffins Fratercula arctica and Razorbills Alca torda alter their chick provisioning behaviour when equipped with tracking loggers.AimsTo test whether feeding data from global positioning system (GPS) tags in a companion project represented normal behaviour, we examined the effect of externally mounted GPS loggers on parental effort of Atlantic Puffins and Razorbills through chick measurements and video recordings to determine individual responses to tagging.MethodsWe compared chick growth, nest attendance and provisioning between breeding pairs with and without tagged birds (nest-level), as well as between tagged and untagged mates (mate-level) with the aim of revealing responses of untagged partners to the tagging of their mate.ResultsWe found all measures of parental effort compared at the nest-level to be similar between nests with one tagged adult and nests without tagged birds. However, video recordings revealed differences in individual behaviour in both species, in which untagged partners spent more time provisioning the chick and also delivered significantly more food to chicks than their tagged partners, though partners shared nest attendance.ConclusionBehaviours revealed through video recordings showed that the GPS tags introduced bias against detecting where adults forage for their chicks. Future tracking studies should consider measures of tag effect at both the mate- and nest-level as well as the potential bias in the movement data when making biological inferences.