Fig. 6: Year-round changes in skip-breeder and post-partum Weddell seal dive durations.
From: Iron mobilization during lactation reduces oxygen stores in a diving mammal
Weighted mean ± SE dive duration of female Weddell seals that were (left) instrumented as skip-breeders in years 2010–2012. Some females returned after the winter foraging period and gave birth (blue, n = 12) while others failed to produce a pup (black, n = 8); data redrawn from Shero et al. 201831, and are the same seals included in this study. (Middle) Dive duration across lactation; skip-breeder value from Shero et al. 2018, lactating female value from Sato et al. 2003101 (n = 8). During late-summer (right), post-partum females were instrumented at 35 dpp in years 2013–2017 and dive durations decreased during the post-weaning period relative to durations during the lactation period (n = 40), whereas skip-breeder dive durations did not (n = 19); data from Beltran et al. 202130 and are the same seals included in this study. Only animals with >50 dives per month were included in the weighted mean. Generalized Additive Mixed-effect Models were used to test for significance; Asterisk = significant difference between reproductive classes.
