Abstract
The use of biologging and tracking devices is widespread in avian behavioral and ecological studies. Carrying these devices rarely has major behavioral or fitness effects in the wild, yet it may still impact animals in more subtle ways, such as during high power demanding escape maneuvers. Here, we tested whether or not great tits (Parus major) carrying a backpack radio‐tag changed their body mass or flight behavior over time to compensate for the detrimental effect of carrying a tag. We tested 18 great tits, randomly assigned to a control (untagged) or one of two different types of a radio‐tag as used in previous studies in the wild (0.9 g or 1.2 g; ~5% or ~6–7% of body mass, respectively), and determined their upward escape‐flight performance 1, 7, 14, and 28 days after tagging. In between experiments, birds were housed in large free‐flight aviaries. For each escape‐flight, we used high‐speed 3D videography to determine flight paths, escape‐flight speed, wingbeat frequency, and actuator disk loading (ratio between the bird weight and aerodynamic thrust production capacity). Tagged birds flew upward with lower escape‐flight speeds, caused by an increased actuator disk loading. During the 28‐day period, all groups slightly increased their body mass and their in‐flight wingbeat frequency. In addition, during this period, all groups of birds increased their escape‐flight speed, but tagged birds did so at a lower rate than untagged birds. This suggests that birds may increase their escape‐flight performance through skill learning; however, tagged birds still remained slower than controls. Our findings suggest that tagging a songbird can have a prolonged effect on the performance of rapid flight maneuvers. Given the absence of tag effects on reproduction and survival in most songbird radio‐tagging studies, tagged birds in the wild might adjust their risk‐taking behavior to avoid performing rapid flight maneuvers.
Highlights
The use of biologging and tracking devices has become a common and widespread practice when studying animals in the wild
Tracking devices have revealed intriguing data on dispersal and migratory behavior (e.g., Willemoes et al, 2015), where animals can be followed over thousands of kilometers (Egevang et al, 2010), as well as information at smaller spatial scales, such as social structures within populations using proximity logging or localizing individuals directly (Amrhein et al, 2004; Farine et al, 2015; Snijders et al, 2014)
We show that the speed of upward escape flights was significantly affected by the birds’ actuator disk loading, which is related to the ratio of body mass and wing span
Summary
The use of biologging and tracking devices has become a common and widespread practice when studying animals in the wild. We tested how different types of backpack radio- tags affect the escape-flight performance of wild-caught great tits (Parus major), focusing on whether or not these birds adapt their body mass or behavior over time to carrying the tag. A heavier bird, a tagged bird, or a bird with smaller wings will have a relatively larger disk loading and would need to invest more in order to rapidly fly upward compared to a lighter, untagged, or larger-winged conspecific Using this model, we tested how escape-flight performance was affected by the weight of the device, and how birds adapted to the tag during a month of deployment
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
