2009 10 7 How do we identify individual whale flukes? Print
Written by Andrew Stevenson   

Allied Whale at College of the Atlantic has a catalogue of some 7,000 individual North Atlantic humpback whale fluke identification photographs. When a new fluke id is sent in, at least two people have to take that new fluke id through the catalogue to either match it with an existing photograph, or assign it a unique identifying number as a newly identified whale. There has to be at least three points of matching identification. If it is matched, two Allied Whale staff have to confirm the match. To take a new fluke id photgraph through the entire catalogue of 7,000 individual whale ids would take days.

To try to make this process somewhat easier, there are five basic types of whale flukes: 1. Mostly white. 2. 25% white. 3. Half white, half black. 4. 25% black. 5. Mostly black. With some luck, one might only have to look into one type- this would usually only occur in mostly white or black. Often one can eliminate three types, and look through only two types. Sometimes one has to look through three types, especially if not 100% of the fluke can be seen.

Dr Peter Stevick at Allied Whale has come up with some sub-types that can make the process of identification easier. These include- 'typical'; 'eyes white surrounded by black'; 'wide black trailing edge'; 'wide black leading edge'; 'fireworks'; 'white on trailing edge'; 'straightsided'; 'rounded not to notch'.

None of this makes much sense until you see the diagrams below depicting these types and sub-types. Photographs of whale flukes are not always ideal. Sometimes they are dark, sometimes incomplete, often at an angle and not from directly behind, and sometimes the angle of the fluke is not vertical. Often a spash or sunlight refection will obscure part of the fluke. There is no computer software programme that can reliably identify whale flukes. It is still down to the human eye to make the judgement call. Here are the five basic types and the various sub-types.