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Sampling Effort

During the three months of data collection, we made 20 independent recordings of whale and dolphin behaviours. Of these six took place in November, eight in December and six in January (Table 4). In total, 70 hours were spent searching for cetaceans and observing them, covering in the three months a total of 800 nautical miles

Total boat interaction behaviours for all species

Total boat interaction behaviours represented in percentage per each species disregarding behavioural states A) Stenella attenuata, B) Tursiops truncatus, C) Physeter macrocephalus, D) Lagenodelphis hosei, E) Stenella longirostris. In= Indifference, Ap= Approach, FtF=Face to face, Av= Avoidance, De= Defecation, Tt=Tail tapping, Brt=Breath, Bu=Bubbles, Brh=Breach, H-b=half-breach, B_b=Breach-bomb, Co=Contact, As=Association, Di =Dive, Di-t-o= Dive tail

 

We summed up all behaviours for each species observed and calculated the relative frequency for each behaviour. Different species react differently when the boat approaching from performing the whole behavioural range like Stenella attenuata, to performing just 2 behaviours like Physeter macrocephalus. 

Accumulation factor

Correlation between the proportion of face to face and the time of the encounters in A) Tursiops truncatus and B) Stenella attenuata

 

We observed a negative correlation between the percentage of face to face and the date of the encounter (representing the timeline from low tourist season and high tourist season). Regarding the case of Tursiops truncatus the correlation was not faound to be significant but in Stenella attenuata, We obtain a p-value of 0.002.

Distress behaviours

Proportion of each distress behaviour in A) Tursiops truncatus B) Stenella attenuata

 

We calculated the proportion of each “distress” behaviour to the total. As can be seen from the bar chart, in both species tail tapping was the most prominent distress behaviour. Breach and breach bomb were not present in the distress display of Tursiops truncatus, but both were present in Stenella attenuata.


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Last updated: 05/17/18