Table 2. Mean (± S.D.) foraging success parameters by year, season, and tagging location (ANNU - Año Nuevo, California and SABE - Islas San Benito, Mexico).
| Season | Year | # Females | # Pups | Natality | Mass Gain(kg) | SD | Rate Mass Gain (kg day) | SD | % MassGain | SD | EnergyGain | SD | Rate EnergyGain (MJ/day) | SD |
| Post-breeding | 2004 | 4 | – | – | 51.9 | 21.6 | 0.6 | 0.2 | 17.9 | 7.6 | 1047.4 | 605.3 | 12.8 | 7.2 |
| 2005 | 18 | – | – | 72.3 | 23.7 | 0.9 | 0.3 | 22.9 | 8.7 | 1105.6 | 563.0 | 14.11,2 | 7.0 | |
| 2006 | 19 | – | – | 69.0 | 24.7 | 0.9 | 0.3 | 21.8 | 8.9 | 1157.8 | 566.4 | 14.53,4 | 7.5 | |
| 2007 | 18 | – | – | 82.4 | 19.1 | 1.1 | 0.3 | 25.8 | 6.3 | 1413.6 | 471.9 | 19.6 | 7.5 | |
| 2008 | 22 | – | – | 74.1 | 25.1 | 1.0 | 0.3 | 22.4 | 7.8 | 1239.0 | 530.4 | 16.7 | 7.3 | |
| 2009 | 13 | – | – | 87.8 | 19.9 | 1.2 | 0.2 | 26.8 | 7.6 | 1727.3 | 760.0 | 23.61,3 | 9.8 | |
| 2010 | 21 | – | – | 81.3 | 19.2 | 1.1 | 0.3 | 23.1 | 6.2 | 1645.2 | 569.9 | 22.32,4 | 8.1 | |
| ANNU PB Mean | – | – | – | 75.4* | 21.6 | 1.0 | 0.3 | 23.1* | 7.5 | 1321.2* | 576.9 | 17.6* | 8.0 | |
| Post-molting | 2004 | 23 | 22 | 95.7 | 267.0 | 40.2 | 1.2 | 0.2 | 95.5 | 14.3 | 4369.91,2 | 677.2 | 19.5 | 2.9 |
| 2005 | 22 | 18 | 81.8 | 266.9 | 65.4 | 1.2 | 0.2 | 98.0 | 21.7 | 4146.0 | 912.4 | 19.2 | 3.3 | |
| SABE 2005 | 6 | 6 | 100.0 | 286.6 | 36.0 | 1.3 | 0.2 | 120.7 | 18.2 | 4108.7 | 592.7 | 18.5 | 3.2 | |
| 2006 | 20 | 17 | 85.0 | 239.6 | 84.5 | 1.1 | 0.3 | 89.0 | 30.2 | 3458.31 | 1161.3 | 15.7 | 4.5 | |
| 2007 | 19 | 13 | 68.4 | 249.7 | 55.1 | 1.1 | 0.2 | 91.4 | 21.8 | 3484.72 | 846.0 | 15.2 | 3.5 | |
| 2008 | 14 | 12 | 85.7 | 260.8 | 77.6 | 1.2 | 0.3 | 94.1 | 30.7 | 3913.2 | 1323.6 | 17.5 | 5.5 | |
| 2009 | 7 | 6 | 85.7 | 271.4 | 58.0 | 1.3 | 0.2 | 103.2 | 34.2 | 4552.2 | 752.2 | 21.8 | 3.5 | |
| 2010 | 15 | 13 | 86.7 | 274.8 | 52.2 | 1.2 | 0.2 | 94.9 | 18.0 | 3630.1 | 650.6 | 16.3 | 2.1 | |
| ANNU PM Mean | – | – | 84.1 | 261.5* | 61.9 | 1.2 | 0.2 | 95.2* | 24.4 | 3864.1* | 903.3 | 17.9 | 3.6 |
All values are determined from empirical measurement of body composition and mass estimates calculated as the difference between deployment and recovery, after correction for time on land. Identical numeric superscripts denote annual differences within seasons. (*) denotes significant differences across seasons. SABE animals were not included in the statistical comparisons.