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The relationship between the environment and the small-scaled behavior of marine animals is not fully understood. This is largely due to the difficulty in obtaining environmental datasets with a high spatiotemporal precision. The problem is particularly pertinent in assessing the influence of environmental factors in rapid high energy consuming behavior such as seabirds take-off. Here, to fill the gaps in existing database, we employed novel techniques using animal-borne sensors with motion records to estimate parameters on wind and ocean waves, and evaluated their influence on wandering albatrosses take-off. The measurement revealed that the wind speed and the wave height that the wandering albatrosses experienced during take-off ranged from 0.7 ∼ 15.4 m/s and 1.6 ∼ 6.4 m, respectively. The four indices that were measured (flapping number, frequency, running speed, and duration on the sea surface) also varied with the environmental conditions (i.e., flapping number varied from 0 to over 20). Importantly, taking-off was easier under higher wave condition in the constant wind speed, and take-off effort increased only when both wind and waves were gentle. Our data suggests that both ocean waves and winds play important roles in albatross take-off, and advances our current understanding of albatross flight mechanisms.Impact statementWinds and ocean waves condition experienced by albatrosses were estimated using animal-borne recorder and revealed that taking-off was easier under higher wave condition in the constant wind speed.

The way goal-oriented birds adjust their travel direction and route in response to the wind significantly affects their travel costs. This is expected to be particularly pronounced in albatrosses, which employ a wind-dependent flight style called dynamic soaring. Dynamic soaring birds in situations without a definite goal, e.g. searching for prey, are known to preferentially fly with tail-to-side winds to increase the speed and search area. However, little is known about their reaction to wind when heading to a definite goal, such as returning to their nest. For example, returning tracks of albatrosses vary from beelines to zigzags similar to that of sailboats; however, there is no empirical test of whether the wind causes this variation. Here, based on the similar wind-dependent speed between albatrosses and sailboats, we tested whether the time-minimizing strategies used by yacht racers can explain the locomotion patterns of wandering albatrosses. We predicted that when the goal is located upwind or downwind, albatrosses should (i) deviate their travel directions from the goal on the microscale and (ii) increase the number of turns on the macroscale. Both hypotheses were supported by track data from albatrosses and racing yachts in the Southern Ocean confirming that albatrosses qualitatively employ the same strategy as yacht racers. Nevertheless, albatrosses did not strictly minimize their travel time, likely making their flight robust against wind fluctuations. Our study provides the first empirical evidence of tacking in albatrosses and demonstrates that man-made movement strategies provide a new perspective on the laws underlying wildlife movement.