Ray Turner's picture

Evidence

I have been thinking about evidence since I listened to an episode of Saving Species on BBC radio last week(?) and after commenting on some recent observations decided to open a discussion here.

The programme featured an article about the demise of the Slender Billed Curlew Numenius tenuirostris now widely believed to be extinct. The interviewee, the journalist Horatio Clare, has been attempting to establish if the species is indeed still extant. During the interview Horatio cited a person who had reported seeing a SBC in 2010, this person provided field notes that are widely agreed to be excellent and most authorities apparently think that on balance the person did see a SBC. However due to the lack of photographic evidence the sighting is highly unlikely to be ratified.

The question is then, what level of evidence is necessary to confirm an observation (in the wider context, not specifically on iSpot)?

Obviously it depends on context to a degree; some species need dissection under a microscope for accurate determination, but for others are field notes sufficient? It was not that long ago field sketches were commonly used, indeed a friend of mine is still employed to sketch archaeological excavations.

Ray

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Thistle's picture

Depends

Doesn't it depend on what you want the ID for? If it's simply for interest then a lower standard of proof is likely to be acceptable. To show that a species isn't extinct I think I would want a bit more.

A rough verbal description leading to a decision in terms of "It sounds like a ..." may be fine for the former. Something more tangible - a photo, a feather, a drop of blood, ... - would be better for the latter: something that can be verified by others at a later date. I don't think I'd be convinced by a single person's field notes no matter how good they were. Notes made independently by two or more people would be better but still nowhere near as good as tangible evidence.

(cf proof beyond reasonable doubt in a criminal court vs proof on the balance of probabilities in civil matters.)

Ray Turner's picture

Agree, sort of

I tend to agree, however I keep thinking we would have accepted good field notes by an authority as quite I high level of proof not so long ago and you only have to spend a little time on iSpot to see how unreliable photos can be for certain species (and I’m not a mycologist). Personally I would find good field notes from two independent witnesses, willing to be questioned (assuming their accounts stood up), adequate beyond reasonable doubt.

Ray

Ray

Thistle's picture

Yes, you're right

Perhaps I ought to have said a set of good photos showing sufficient features for an accurate ID.