Table 4

Non-releasable California sea lions that were part of a previous study (Cook et al) that compared behavioural performances in spatial memory tests with hippocampal volumes, measured using MRI (n=6)

Blinded study numberAge class at strandingReason for non-releasabilityMRI hippocampal findingsBehavioural testing resultsDispositionCause of death
23Non-neonateRestrandNormalNormalDiedOther
28Non-neonateTraumaNormal*Slow task acquisitionDiedOther
30Non-neonateRestrandBilateral hippocampal atrophyPoor delayed maze testingAliveNA
31Non-neonateRestrandInitial MRI normal; post-placement MRI showed unilateral hippocampal atrophyNormalAliveNA
32Non-neonateRestrandNormalNormalAliveNA
33NeonateAgeLeft hippocampal atrophyPoor maze and spatial memory performanceAliveNA
  • These assessments were performed following stranding and prior to placement. Neurological cases are shaded in grey.

  • *This animal had multiple cerebellar infarcts secondary to trauma, which were likely responsible for neurological signs and behavioural testing changes.

  • NA, not applicable.