6). A model with separate parameters for each of the seven subpopulations failed to converge, however, such a model did converge when the length data from French Frigate Shoals was excluded. This model was a much better fit than one with shared parameters for the six remaining subpopulations after French Frigate Shoals was excluded (▵AICc = −53.624 for the full data set, ▵AICc = −34.857 for the reduced data set). A French Frigate Shoals length curve was fitted by iteratively fixing the asymptote at varying values as described in the Methods. Resulting curves for each subpopulation exhibit marked variability. To demonstrate differences in the

growth trajectories, we chose an arbitrary reference length (180 cm) and calculated the Selleckchem Ku0059436 expected age when this length would be attained at

each site. This ranged from just over age 3 yr at sites with relatively rapid growth to between age 6 and 7 yr at French Frigate Shoals and Lisianski Island (Fig. 3). As with length, we found no support for sex differences in axillary girth growth. A sex effect model of pooled data was not an improvement compared to equal parameters for males and females (AICc increased by 0.485). Testing for subpopulation differences in girth growth patterns within a model comparison framework was hampered by difficulties in achieving convergence. Efforts to fit the three-parameter model to data from three (French Frigate Shoals, Laysan Island, and Pearl and Hermes Reef) Rucaparib medchemexpress of the seven subpopulations failed. Therefore, two-parameter (with the asymptote estimated iteratively) models were fitted to these sites. Site-specific girth growth curves varied similarly to growth in length. The age when seals were expected to reach an arbitrary reference (120 cm) girth varied from just over 3 yr in the main Hawaiian Islands to 9 and 12 yr at French Frigate Shoals and Lisianski Island, respectively (Fig. 4). Table 2 presents estimated parameters for length and girth models. Kenyon and Rice (1959) reported that adult female Hawaiian monk seals

appeared to be larger than males. This was apparently based only on visual assessment, and in the context of the authors’ landmark comprehensive description of the species’ natural history, was likely offered as a tentative observation. Yet, adult female monk seals exceeding males in size has been oft-repeated in publications and has seemingly taken on a certainty that the original authors likely did not intend. Here we find no evidence of sexual dimorphism in growth or body size. Antonelis et al. (2003) likewise found no sex differences in the size of pups at weaning. There were striking differences in growth curves among the various monk seal subpopulations. The fitted parameters (Table 2) for each site are provided for reference, though when considered individually, they provide limited insight into growth patterns.