Hooker et al.: Behavioral reactions of Hyperoodon ampullatus to biopsy darting and tag attachment procedures 
305 
Table 1 
Number of whales showing different reaction-types to tag- 
ging and biopsy deployment attempts (percentages shown 
in parentheses). 
Reaction level 
Total 
Low- no. of 
Event None level Moderate whales 
Tag-hit 
2 (7%) 
19 (65%) 
8 (28%) 
29 
Biopsy-hit 
3 (11%) 
20 (74%) 
4(15%) 
27 
Tag-miss 
33 (60%) 
21 (38%) 
1 (2%) 
55 
Biopsy-miss 
16 (80%) 
3 (15%) 
1 (5%) 
20 
Goodness-of-fit G-tests 
were used to compare 
reactions 
to different techniques and under different conditions. 
Small sample sizes often necessitated pooling between 
categories. Because reactions to misses tended to be lower- 
level they were pooled between none and low to moderate, 
whereas reactions to bits tended to be higher-level and 
were pooled between none (or low) and moderate. 
Results 
Forty-seven biopsy attempts were made on northern bot- 
tlenose whales in 1996 and 1997 (Table 1). Of these, 27 
attempts hit the whale and 20 obtained a skin and blub- 
ber sample. Six attempts hit, but did not retain a sample 
(primarily resulting from low hits at the water line). One 
dart sank after hitting a whale. Video footage was taken of 
18 biopsy hits (15 successful) and 11 biopsy misses. 
Eighty-four tagging attempts were made between 1996 
and 1998 (Table 1). Twenty-nine attempts hit the whale 
but only six successfully attached (one for only 30 sec- 
onds). Video footage was taken of 15 tag hits (three suc- 
cessful attachments) and 34 tag misses. 
The majority of whales showed no or low-level reactions 
to both tag and biopsy attempts (Table 1). No strong re- 
actions were observed during our study. The whales react- 
ed to 93% of the tag hits and 89%- of the biopsy hits, but 
reacted to only 40% of the tag misses and 20%> of the bi- 
opsy misses (Table 1). Reactions (categorized as none, low, 
or moderate) were significantly greater for hits than for 
misses (G=50.3, PcO.OOl, 2 df). Reactions to tag hits were 
not significantly different from the reactions to biopsy hits 
(G=1.51, P=0.47, 2 df). Of the 6 successful tag hits, 2 ani- 
mals gave a hard tail flick, accelerated and dove (moder- 
ate reaction), 1 animal accelerated and dove, and 3 dove 
rapidly or flinched (low-level reactions). 
The type of reaction to a hit was significantly related to 
the animal’s behavioral state prior to the tagging or biopsy 
attempt (comparison for all hits of behavioral state (log- 
ging vs. milling or traveling) and reaction (none [or low] 
vs. moderate) G=4.04, P=0.044, 1 df). Low-level reactions 
were most common for traveling or milling whales, where- 
as logging whales were more likely to show stronger reac- 
Table 2 
Gender of biopsied whales in= 20) and respective reactions. 
Reaction level 
Total 
no. of 
whales 
Gender 
None 
Low- 
level 
Moderate 
Male 
0 
5 
2 
7 
Female 
2 
9 
2 
13 
tions, especially to tag hits (Fig. 2). There was also a simi- 
lar relationship between behavior and reaction to misses, 
although whales rarely showed a moderate reaction to a 
miss (comparison of behavioral state [as above] and reac- 
tion [none vs. low or moderate] G=4.02, P=0.045, 1 df. Fig. 
2). Reactions to hits of animals in groups were similar to 
those for lone individuals (G=0.767, P= 0.38, 1 df). There 
was an effect of sea state on reaction type, but only for 
missed shots (comparison of sea state [>Beaufort 2 with 
Beaufort <2], G=4.38, P=0.036 1 df. Fig. 3). This effect was 
greater for tag misses (G=6.80, P=0.009, 1 df) than for bi- 
opsy misses (G=2.41, P=0.12, 1 df). 
No avoidance of the research vessel was observed after 
tagging or biopsy attempts. For the majority of attempts, 
animals remained at the surface. If the animals made a 
shallow dive, they usually returned to the research vessel 
within a few seconds or were photographed again within 
a few minutes of the tagging or biopsy attempt (for 82% of 
all attempts, whales returned to the surface and remained 
with the research vessel for at least five minutes). There 
was little difference in the likelihood of encounters ending 
within five minutes between tagging and biopsy attempts 
or between hits and misses. Furthermore, encounters in- 
cluding tagging or biopsy attempts were not shorter in du- 
ration than encounters without any tagging or biopsy at- 
tempt (one-tailed f -tests, P>0.05). 
No significant difference between the reactions of males 
and females was found (G=2.1, P= 0.35, 2 df, Table 2), but 
samples sizes were small and did not adequately repre- 
sent the population. 
Discussion 
The response rate of northern bottlenose whales to biopsy 
hits (89%) was greater than that found for baleen whales 
(right whales, Eubalaena glacialis, 19%; Brown et ah, 
1991; humpback whales, Megaptera novaeangliae, 50%, 
Weinrich et ah, 1991), but was similar to that recorded 
for other odontocetes. A 100%’ response rate was found for 
sperm whales ( Physeter macrocephalus) (Whitehead et ah, 
1990) and for bottlenose dolphins (Weller et ah, 1997), and 
an 81% response rate was found for killer whales ( Barrett- 
Lennard et ah, 1996). Reactions of bottlenose dolphins 
consisted of an observable short-term change in behavior 
(Weller et ah, 1997). Momentary shakes or accelerations 
were observed for killer whales (Barrett-Lennard et ah, 
