Excess Baggage for Birds: Inappropriate Placement of Tags on Gannets Changes Flight Patterns

Abstract

Devices attached to flying birds can hugely enhance our understanding of their behavioural ecology for periods when they cannot be observed directly. For this, scientists routinely attach units to either birds' backs or their tails. However, inappropriate payload distribution is critical in aircraft and, since birds and planes are subject to the same laws of physics during flight, we considered aircraft aerodynamic constraints to explain flight patterns displayed by northern gannets Sula bassana equipped with (small ca. 14 g) tail- and back-mounted accelerometers and (larger ca. 30 g) tail-mounted GPS units. Tail-mounted GPS-fitted birds showed significantly higher cumulative numbers of flap-glide cycles and a higher pitch angle of the tail than accelerometer-equipped birds, indicating problems with balancing inappropriately placed weights with knock-on consequences relating to energy expenditure. These problems can be addressed by carefully choosing where to place tags on birds according to the mass of the tags and the lifestyle of the subject species.

Contrasting effects of GPS device and harness attachment on adult survival of Lesser Black‐backed Gulls Larus fuscus and Great Skuas Stercorarius skua

“…, Vandenabeele et al . ) and attachment methods of devices, e.g. the topic of this study, are taken.…”

Social and Spatial Reintegration Success of New Caledonian Crows (Corvus moneduloides) Released after Aviary Confinement

“…The six released NCCs that I located mixed with unbanded NCCs and foraged on woodland food such as wild berries. Long term captivity and the wearing of tail transmitters can potentially affect birds' flying ability on their release (Dominguez et al 2010, Vandenabeele et al 2014), but there was no obvious difference in the general behavior of the radio-tracked NCCs compared to unbanded NCCs. I did not identify any of the six NCCs that had previously been released in the valley in 2012 and April 2014.…”

Seabirds as samplers of the marine environment – a case study of northern gannets

“…This is well below the potential threshold of 3 % (Phillips et al, 2003;see Vandenabeele et al, 2012). Although attachments to the tail may have a negative influence on flight behaviour (Vandenabeele et al, 2014), most pairs successfully incubated their eggs and/or raised their chicks, similar to non-handled nests, with no visible effects on bird behaviour.…”