Figure 3: Inferred timing of flightless moult in four dual-equipped
puffins. Immersion data were combined between two geolocators for each
puffin. The green line represents time spent dry per day
(propfligth) and the blue line is the 5-day rolling
average of this (propflight-5). The blue bar underneath
each plot represents moult inferred on the first pass of the moult
identifiation process, the red bar represents a potential second
flightless moult identified by the second pass.
All moult periods occurred close to equinox periods, when the
latitudinal accuracy of light level geolocation is greatly reduced. The
average position of inferred moult was used to graphically represent
moult location (figure 4), given that puffins are unlikely to move
extensively when flightless, and most of the variation in location
during moult is almost certainly due to error in location estimates.
Both individuals with two inferred moult periods had more extensive
migrations than those with one (table 2), with the autumn flightless
moult occurring when they were furthest from their colony and the spring
moult when much closer to the colony (figure 4).