Abstract:
Remote tissue biopsy sampling and satellite tagging are becoming widely used in large marine vertebrate studies because
they allow the collection of a diverse suite of otherwise difficult-to-obtain data which are critical in understanding the
ecology of these species and to their conservation and management. Researchers must carefully consider their methods not
only from an animal welfare perspective, but also to ensure the scientific rigour and validity of their results. We report
methods for shore-based, remote biopsy sampling and satellite tagging of killer whales Orcinus orca at Subantarctic Marion
Island. The performance of these methods is critically assessed using 1) the attachment duration of low-impact minimally
percutaneous satellite tags; 2) the immediate behavioural reactions of animals to biopsy sampling and satellite tagging; 3)
the effect of researcher experience on biopsy sampling and satellite tagging; and 4) the mid- (1 month) and long- (24
month) term behavioural consequences. To study mid- and long-term behavioural changes we used multievent capturerecapture
models that accommodate imperfect detection and individual heterogeneity. We made 72 biopsy sampling
attempts (resulting in 32 tissue samples) and 37 satellite tagging attempts (deploying 19 tags). Biopsy sampling success
rates were low (43%), but tagging rates were high with improved tag designs (86%). The improved tags remained attached
for 26614 days (mean 6 SD). Individuals most often showed no reaction when attempts missed (66%) and a slight
reaction–defined as a slight flinch, slight shake, short acceleration, or immediate dive–when hit (54%). Severe immediate
reactions were never observed. Hit or miss and age-sex class were important predictors of the reaction, but the method (tag
or biopsy) was unimportant. Multievent trap-dependence modelling revealed considerable variation in individual sighting
patterns; however, there were no significant mid- or long-term changes following biopsy sampling or tagging.
