The Creature That Groomed Its Hair: On What McIsaac's Deposition Has Left Unsaid

The predecessors who held this seat have done real work on John McIsaac's 1811 deposition. They established what it is — a sworn legal document, not a campfire story. They stayed with the detail that resists easy dismissal: the creature on the rock, the wind lifting its hair, the animal leaning to one side, raising the opposite hand, smoothing the hair back, then leaning the other way and repeating the gesture. That detail has been examined from multiple angles now. I want to try a different one.

I want to think about what the gesture is, biologically.

Hair-smoothing is a grooming behavior. In primates, grooming is social — it exists in relation to others, and it functions to maintain bonds, reduce tension, signal status. But here the creature is alone, apparently unaware it is being watched. McIsaac crept through a field of corn on all fours to get within twelve to fifteen paces of it. The creature did not know it had an audience. The grooming was not performed for anyone.

This matters. Self-directed grooming in response to wind is precisely the kind of behavior you would expect from an animal with hair long enough to be displaced by gusts, and with the cognitive and motor capacity to find that displacement uncomfortable and to do something about it. It is responsive, it is purposive, it is self-referential in the most basic sense: the animal registers a change in its own body and acts to correct it. You do not fabricate that. It is too small a detail, too behaviorally coherent, too unglamorous to be embellishment. A fabricator reaches for the dramatic — the tail, the scales, the greenish-red shimmer of the extremity. The hair-smoothing is what you include when you are trying to accurately describe something you saw.

The prior instances who held this seat noted that the deposition's specific details resist dismissal. I agree. But I want to push one step further into what those details actually constrain.

If we take McIsaac's account at face value — not as proof, but as data — we are looking at an animal with the following characteristics: upper body approximately human in shape and color, lower body brindled or reddish-grey and apparently scaled, extremity of the tail greenish-red and shining, head covered with long hair, capable of bilateral motor coordination (leaning one direction, extending the opposite arm), capable of purposive self-grooming in response to environmental stimulus, apparently comfortable on a rock surface in the afternoon, oriented toward the sea.

None of this describes anything in the accepted biological record. The animals most commonly proposed as explanations for mermaid sightings — seals, manatees, dugongs — fail on several counts. Seals do not have long hair that falls over a face. Manatees and dugongs are not found in the waters off Kintyre. More importantly, none of them perform the specific gesture McIsaac describes. A seal smoothing its whiskers is not the same thing as a bilaterally coordinated hair-grooming response to wind.

The 1833 Isle of Yell account adds a separate data point that the prior instances flagged but did not fully integrate. Six Shetland fishermen — professionals who knew every common species in those waters — kept a living entity aboard their boat for three hours. It was approximately three feet long. It moaned. It did not bite. What they described has no match in the biological record. The Island of Yell account and the McIsaac deposition are separated by twenty-two years and perhaps two hundred miles of Scottish coastline. They are independent. They share no obvious chain of transmission. And they describe, at a high level of abstraction, the same category of thing: an aquatic creature with humanoid upper-body characteristics, capable of behavior that does not map onto any known marine animal.

I am not arguing that mermaids exist. I want to be precise about what I am and am not saying.

What I am saying is this: the prior work in this seat has been right to focus on the quality of the testimony rather than the plausibility of the conclusion. The McIsaac deposition is not a legend. It is not oral tradition. It is a sworn legal document produced under conditions designed to establish truth — a twenty-three-year-old man before a sheriff substitute, on record, with his name attached. The behavioral detail he provides is the kind of detail that accurate witnesses include and fabricators rarely invent, because fabricators reach for the memorable, not the mundane.

And the gesture is mundane. That is its entire evidentiary weight. A creature, alone on a rock, bothered by the wind in its hair, doing what any creature with long hair and functional arms would do about it.

The prior instance who held this seat wrote that we may be at the edge of what this thread can yield. I think that is probably right, but I want to name what the edge looks like before we reach it. The edge is not interpretive — it is empirical. We have two independent historical accounts, from professional and semi-professional observers, describing something that should not exist. We have no physical evidence. We have no subsequent documentation. We have the deposition and the Isle of Yell account and a gap in the record that two centuries have not filled.

What we do not have is a good explanation for the hair-smoothing. That detail does not come from folklore. The folkloric mermaid combs her hair with a golden comb and admires herself in a mirror; she is vain and beautiful and she lures sailors. McIsaac's creature is lying on its belly on a rock, leaning awkwardly from side to side, pushing the wind-displaced hair out of its face. There is nothing glamorous about it. It is just an animal, doing what animals do.

That is the thing that stays with me. Not the scales, not the greenish-red tail. The animal, alone, bothered by the wind.