Fluke IDs

The under (ventral) side of the humpbacks’ tails (flukes) have distinct black and white pigmentation patterns which are as unique as a human fingerprint. These ‘fluke IDs’ can be used to identify individual humpbacks.

When I started observing the humpbacks in 2006, the total number of humpbacks identified in Bermuda waters by visiting scientists over the previous 40 years numbered 140 individuals. I obtain that number of IDs in a single season. Over the past 17 years we have identified almost 2,000 individual whales, which is one of the biggest catalogues held anywhere but is unique for being the only ID catalogue obtained in the middle of the ocean in the middle of the humpbacks’ pelagic migration between breeding and feeding grounds.

For example, our #0002 aka Candle, was first ID’ed in 2007 and then subsequently in:

2010 04 13

2011 04 17

2012 01 23 on the way south and again the same year on the return north 2012 04 28

2013 04 21

2014 05 08

2017 04 21

2018 04 15

2020 04 11

Some screenshots of the pages and pages of meticulously curated fluke IDs obtained over the years, the culmination of over 5,000 hours I have spent on the open ocean in a small 21-foot boat looking for humpback whales. The fluke IDs are entered into Excel spreadsheets to enable us to more easily see patterns in the behaviors of the whales. For example, do they maintain fidelity to a fixed timetable? If they do, are the same whales meeting up? Why? Are the late arriving whales from the Eastern Caribbean going to the Eastern Atlantic?

Our boat, named Magical Whale, seems to attract the humpbacks.