Accelerometry reveals an impact of short-term tagging on seabird activity budgets

Miniaturized data loggers have revolutionized the study of animal movement. However, data obtained from tagging could be compromised by impacts on animal welfare and behavior. We evaluated short-term (activity budgets, foraging trip metrics, overall dynamic body acceleration [ODBA] of flying, wingbeat frequency, adult mass, and nestling mass) and long-term metrics (breeding success and survival) for breeding female Black-legged Kittiwakes (Rissa tridactyla) tagged with both GPS and accelerometer tags (5.2% of body mass), birds tagged with only accelerometers (1.0% of body mass), and untagged birds. Breeding success, survival, adult mass, and nestling mass were not affected by tagging, and there were no differences in trip metrics, ODBA, and flapping frequency for birds tagged with GPS and accelerometer packages vs. only accelerometers. However, accelerometry revealed that, when tagged for 3 days with GPS and accelerometer tags, kittiwakes reduced the amount of time spent flying by 30%. Impacts of short-term tag deployments were detected by measuring metrics over the same short timescale, rather than through measurement of long-term metrics. We suggest that tagging birds alters their behavior, but that such effects may not be detected using coarse-scale measures, such as reproductive success, survival, and body mass, due to behavioral accommodation. We recommend that researchers examine, or at least take into consideration, behavioral changes that may be associated with tagging, even if there are no clear effects on fitness or condition measures.