Table 1

Best-fit parameter values for different models of changing otter demography fit to age distributions of sea otters found dead before or after EVOS

Model familyRelative log-likelihoodMaximum likelihood (95% confidence limits)
Parameter a (constant)Parameter b (year effect)Parameter d (age effect)Parameter e (interaction)
Fit to prespill carcasses:
 Logistic374.55−47.7348   (−86.4115, 4.1017)−0.1501   (−2.7285, 0.3162)0.02285  (0.00545, 17.5616)0.00097  (−0.00090, 5.7620)
 Modified logistic371.522.38747  (0.82337, 3.58883)0.10258  (−0.01390, 0.24090)−0.31686  (−0.44277, −0.17741)0.00874  (−0.00367, 0.01995)
 Linear369.880.00509  (0.00509, 0.38982)−0.00034  (−0.00034, 0.0000)0.00018  (0.00018, 0.01785)−0.00001  (−0.00001, 0)
Fit to postspill carcasses:
 Logistic503.72−0.8379   (−2.1982, 0.7026)0.5133   (0.2035, 0.8375)0.1798   (0.0812, 0.3179)−0.0576  (−0.0922, −0.0269)
 Modified logistic507.55−1.1747   (−2.2327, 0.2638)0.5225   (0.3141, 0.7037)0.06915  (−0.0570, 0.1842)−0.0706  (−0.0980, −0.0436)
 Linear503.120.2536   (−0.0033, 0.3332)0.1062   (0.0612, 0.1150)0.03455  (0.0179, 0.0495)−0.0107  (−0.0135, −0.0064)
  • Relative negative log-likelihood values, maximum likelihood parameter estimates, and one-dimensional 95% confidence limits are given for the best-fit model for each model family. All six best-fit models assumed an initial stable age distribution. See text for definitions of parameter effects.