For some data sets, convergence was not achieved despite multiple trials with varying starting parameters. In these cases, we fitted multiple curves changing the value of a fixed asymptote (L∞) so that only a and b were estimated. This process continued, changing the value of L∞ by 1 cm, until the model with the lowest residual sum of squares was obtained. A total of 655 length and 632 girth measurements were recorded, approximately evenly represented by female (52%) and male (48%) seals. The sample distribution of measurements was uneven

across subpopulations, years, and ages (from age 1 to 20 yr), with a high proportion of young seals and most seals measured at French Frigate Shoals and Laysan Island (Table 1, Fig. 2). Nearly all seals had been born at the same subpopulation where they were measured. For example,

at all sites except Midway Atoll, only 0–4 seals Selleck Acalabrutinib selleck compound measured had been born elsewhere. At Midway Atoll, in contrast, only 27 of 43 (63%) measured seals had been born there. Notably, only 1 of 10 seals older than age 7 yr measured at Midway had been born there. Eight measurements were from seals that had moved to Midway Atoll from Pearl and Hermes Reef, three were from Kure Atoll, and four were from seals that had been born at French Frigate Shoals, rehabilitated in captivity, and released at either Midway or Kure Atoll. Previously rehabilitated seals from French Frigate Shoals also accounted for one and two measurements, respectively, at Pearl and Hermes Reef and

Kure Atoll. A total of 399 seals were measured at just one age, and 115 seals were measured twice (at two ages), seven were measured three times, and one was measured four times. The majority 上海皓元医药股份有限公司 of the repeat measurements involved young seals; 77% of the repeat measurements were at ages 2 and 3 yr. The rest were sprinkled among the older age classes. Laysan and French Frigate Shoals had the highest proportion of repeat length measurements (31% and 26%, respectively), whereas no repeat measurements occurred at Lisianski Island and Kure Atoll. To address potential influences of repeated measurements on results, we created a data set consisting of just one length measurement per individual seal (selected with a random number generator) and compared statistical results using these data to the full data set with repeated measures. We did not find evidence that length growth patterns differed among male and female monk seals. Beyond age 3 yr, sex-specific sample sizes at individual subpopulations were insufficient (in many cases zero, see Table 1), so that all sites were pooled to evaluate sex differences in growth curves. A model with separate parameters for the sexes was less well supported (AICc increased by 3.7) relative to a model with one set of parameters for both sexes.