By observing humpback whales on our tours it gives us great insights into their behaviour and social dynamics. Previously we looked at when is the best time to see the whales based on our sightings in 2024. We now wanted to look at what happened on these tours, specifically regarding the humpback whales behaviour. In a past blog we looked at this as well using data from 2022. If you look at that blog you will also see a more in depth explanation of why humpback whales perform certain behaviours. Some hypotheses include:
-Communication
-Feeding
-Showing dominance
-Removing parasites
Quickly, it is also important to explain the different types of surface activities we looked at:
-Breach: This is when the animal jumps out of the water.
-Pec-slap: This is when the animal slaps their pectoral fin onto the surface of the water.
-Rolling: This is when the animal rolls at the surface, usually a pectoral fin will then be raised into the air as well.
-Tail-slap: This is when the fluke (tail) is slapped on the surface of the water.
The most exciting statistic from the data collected in 2024 shows that roughly 1/5 (17.28%) of the time a humpback whale is spotted on a tour it will breach! This is so high it almost sounds unbelievable.
When are Humpbacks the Most Active?
The behaviour of humpbacks changes across the year and even during the day. In the recent blog, mentioned before, you can see when was the best time of year and day to see humpback whales in 2024. So here we will look at these same factors but specifically at what they were doing. The data showed there is roughly the same possibilities to see a humpback no matter the time of day. But something that might change by time of day is how active the humpbacks are. Later in the day there is a higher chance of seeing the humpback whales breach. There is also a slight increase across the day in seeing other surface activities including pec-slaps, rolling and tail-slaps.
Across the year the trend is slightly less clear. Breaching seems to be a bit more likely in the summer months. There is still a high amount of breaching occurring until August, with it dropping off later in the year. The other behaviours tend to fluctuate even more with there not being a clear pattern of when they are performed. Overall, the best month for surface activity by tour was actually February where almost half the tours had some form of activity. The next best was August at 39%, likely due to the high amount of breaches.
Overall, the time of day appears to be more important than the time of year for seeing surface activity of humpback whales. This is because the data is more in line with 2022, whereby later in the day had more activity. Whereas, in 2024 the top month was February and in previous years this month has seen no activity. However, that is because no humpbacks were seen in February 2022. But this shows how much it can change by year. As we are seeing more humpbacks during the winter than in the past, this could be a contributing factor too.
These photographs show rolling humpback whales. Both photographs were taken by Anna Richter.
How do Associations Impact Humpback Whale Activity
Whether or not humpback whales are with other individuals may influence the levels of surface activity they are displaying. This could be associations with other humpback whales or even other species, such as white-beaked dolphins! One of the reasons behind changes in activity levels could be communication if they are ‘talking’ to each other.
Size of the Group
To start with, we looked at the size of the groups, so we looked at when the humpbacks are alone, in a pair or in a group of 3 or more. When we see humpback whales 70.5% of the time they are alone, 18.8% of the time they are a pair and the remaining 10.7% of the time they are in a group of 3 or more! We also compared our results to other studies around the world.
Photographs of pairs of humpback whales. In the one on the right they are lunge feeding. Both photographs were taken by Milla Brandão.
When we spot a humpback whale on a tour, 17% of the time we will also see a breach. If we split this into when they are alone, a pair or a larger group, the numbers stay roughly the same. There will be roughly, a 10-11% chance of a breach. Another study found that when alone the chances of a breach are half (7%) of when the group is 3 individuals or more (14%). The other three surface behaviours do increase, however, as the number of individuals together increases. This is accordance with other studies. As humpback whales get closer together and form a group these ‘quieter’ behaviours are more likely. This makes sense as they wouldn’t need to make as much noise to communicate when closer. This supports the communication hypothesis for producing surface behaviours. It has also been suggested pec-slaps and tail-slaps could be used when joining or leaving a group.
Number of Sightings in the Tour
Knowing that behaviours change depending on the humpbacks proximity to each other we wanted to also look at how these behaviours change during our tours when we do see humpbacks in multiple locations across the bay. For example, research would suggest when we are seeing humpbacks in many locations, further apart, a breach would be more likely whilst the other behaviours should reduce. Breaching did not seem to change based on the number of sightings. There was a decrease in the other three behaviours when multiple sightings occurred though. Again, this could suggest that if the humpbacks are further apart they may rely on these less for communication.
White-Beaked Dolphin Association
The data from multiple years has suggested the association of white-beaked dolphins and humpbacks will lead to more activity. 2024 was no different! When we see this association there is a huge increase in pec-slaps, rolling and tail-slaps. Often when the two species are together they are feeding. Maybe the increase could be communication between the species. Are they coordinating a feed together or are the humpbacks warning them to not take their food?
Overall our analysis of the humpback whale’s activity in 2024 shows how much they will change depending on time and associations. The time of day appears to have a larger influence than time of year on how they behave. The changes between years highlights the complexity of marine ecosystems. Furthermore, group size and interspecies interactions impact the activity levels. By continuing to collect data we will deepen our understanding of humpback behaviour. We can then contribute to more informed conservation strategies and enhance responsible whale-watching.
To excite matters further, we are getting a hydrophone to improve our research at Elding. Who knows what we will learn about their activity and how this coincides with sounds that the humpbacks are making.
These photographs show humpback whales breaching! Both photographs were taken by Rob Hyman.
Rob Hyman
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