Hooker et al: Behavioral reactions of Hyperoodon ampullotus to biopsy darting and tag attachment procedures 
307 
Tag misses 
Reaction type 
□ none 
□ low-level 
a moderate 
Biopsy misses 
Reaction type 
□ none 
□ low-level 
moderate 
Figure 3 
Relationship between sea state and reaction type for tag and 
biopsy misses. Reactions to misses were greater in calm (<Beau- 
fort 2) than in rough (>Beaufort 2) sea states (P=0.036). Per- 
centage of each reaction-type is displayed for these two Beaufort 
sea state categories (number of reactions of each type are shown 
above each bar). 
the six successful tag attachments and one of these 
tags was equipped to record velocity (Hooker and 
Baird, 1999). The whale’s initial reaction to the at- 
tachment of the tag was a rapid acceleration and 
dive. The velocity record showed that this initial in- 
crease dropped within the first two minutes to levels 
observed for the rest of the deployment ( Hooker and 
Baird, 1999). The general behavior of all six tagged 
whales (in terms of surfacing intervals and dive du- 
rations) was also consistent with that observed from 
nontagged whales. Thus, although based on a small 
sample size, it appears that the target animals’ be- 
havior is modified for only a few minutes in a short- 
term reaction to the tagging procedure. 
Previous studies that examined responses to biopsy 
darting have been criticized because of the potential- 
ly confounding effect of the research vessel approach 
(Brown et al., 1994). In our study, the behaviors of the 
whales when first sighted did not change in any no- 
ticeable way during the approach of the research ves- 
sel for photo-identification, and immediately prior to 
the tagging or biopsy attempt. Thus we are relatively 
confident that the reactions we observed were due to 
the tagging or biopsy darting, rather than to the prox- 
imity of the research vessel. However, the approach of 
the research vessel may have caused subtle changes 
in behavior that we did not observe. 
The major cue to which bottlenose whales react 
appears to be the physical impact of the tag or bi- 
opsy, because reaction to hits was much greater than 
reaction to misses (Table 1). Whales also appear to 
react to an acoustic or other sensory cue, evidenced 
by their stronger reactions to tag misses in calm sea 
conditions (when the hit would be more audible or 
the splash more likely to be detected above back- 
ground levels; Fig. 3). 
The primary factor affecting the reaction of bottle- 
nose whales to either tag or biopsy stimulus appears 
to be the behavior of the whale at the time of the 
stimulus. The relative stimulus of a biopsy or tag is 
less for whales involved in traveling or milling than for 
whales lying still at the surface (Fig. 2). Similarly, differ- 
ences in the level of reaction have been observed for hump- 
back whales involved in different activities. Reactions of 
migrating humpback whales were generally lower than 
those of whales on feeding or breeding grounds (Brown et 
al., 1994), and mothers or primary escorts of humpback 
whales (thought to be involved in breeding activity) showed 
less reaction than other whales on the breeding grounds 
(Clapham and Mattila, 1993). Such results have wide im- 
plications for monitoring the effect of various activities 
(e.g. noise pollution) on cetaceans because the likelihood of 
reaction may vary depending on behavioral state. 
Acknowledgments 
We are grateful to all the crew members of Bctlaena who 
participated in fieldwork in the Gully. Research in the 
Gully was funded by the Natural Sciences and Engi- 
neering Research Council (NSERC), World Wildlife Fund 
Canada, and the Canadian Federation of Humane Societ- 
ies. Mere] Dalebout (University of Auckland) determined 
the gender of biopsied whales. S.K.H. was supported by 
a Canadian Commonwealth Scholarship, R.W.B. by an 
NSERC postdoctoral fellowship, and S.G. by an NSERC 
and an Izaak Walton Killam Memorial Scholarship. Lisa 
Balance, David Maehr, and Per Palsboll made helpful com- 
ments on the manuscript. 
Literature cited 
Baird, R. W. 
1994. Foraging behaviour and ecology of transient killer 
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1998. Studying diving behavior of whales and dolphins 
using suction-cup attached tags. Whalewatcher: J. Am. 
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