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Modern Sightings of Putatively Extinct Taxa

By Branden Holmes

Despite being officially listed as extinct (e.g. IUCN, 2015) there are some species (and subspecies) of animals which are still being 'seen'. There have even been several sightings of the Dodo (Raphus cucullatus) since the 1970's, or more than 300 years after the last incontrovertible record of the species which was in c.1638 (Fuller, 2002). Taxonomic and iconographic bias is evident in these sightings as the vast majority of reports concern either mammals or birds1, especially famous ones. This bias is not unexpected for several reasons:

  • Putatively extinct mammals and birds are better known to the general public than animals from other taxonomic groups.
  • Birds and mammals are some of the most readily enountered animals (especially birds).
  • Plants and invertebrates are of much less interest to most people.

 

Only a very few putatively extinct invertebrates could by any stretch of the imagination be called well-known, such as Buller's moth (Aoraia mairi) and the previously thought to be extinct Lord Howe Island phasmid (Dryococelus australis). And even then their fame does not approach anywhere near that of their tetrapod cousins. And equally few non-mammalian non-avian vertebrate species which are believed to be extinct are widely known. Most of the iconic putatively extinct species and subspecies are mammals or birds. Some examples are:

  • The thylacine or Tasmanian tiger (Thylacinus cynocephalus), last seen 7 September 1936.
  • Steller's sea cow (Hydrodamalis gigas), last seen in 1768.
  • Ivory-billed woodpecker (Campephilus principalis principalis), last seen in 1944.
  • Baiji, or Yangtze River dolphin (Lipotes vexillifer), last seen in 2002.
  • Paradise parrot (Psephotus pulcherrimus), last seen in 1928.
  • The Dodo (Raphus cucullatus), last seen c.1668.
  • Passenger pigeon (Ectopistes migratorius), last seen 1 September 1914.

Interestingly, there have been numerous post-extinction (putatively) reports of all of these species, especially of the Thylacine (5,000+). And the so-called 'rediscovery' of the Ivory-billed woodpecker has been widely covered in the scientific literature (Wilcove, 2005), though the video footage taken almost certainly depicts a Pileated woodpecker (Dryocopus pileatus) (Collinson, 2007, and others). Though caution must be heeded as the famousness of these species in itself is probably the cause of some extra number of sightings than would otherwise have been the case if they were species which were otherwise unremarkable. In regards to other members of the groups birds and mammals, and other taxonomic groups (fish, reptiles, amphibians etc.), the observer may simply put down a sighting of an animal unknown to them as simply a species which they are not familiar with. It may not even occur to them that the animal they observed belonged to a species presumed to be extinct.

The three categories

Reported sightings of putatively extinct taxa fall into one of three categories:

  1. Hoaxes or deceptions.
  2. Misidentifications.
  3. Genuine sightings.

In my personal experience those people who report the occurrence of events, or the existence of animals, which are not widely accepted are genuine in doing so. That is, they are not consciously lying. They genuinely believe that they have seen what they claim to have seen, whatever that turns out to be. And this applies equally well to previously known animals, cryptids and miracles. The greater part of the problem then is to determine whether a potential sighting belongs in category 2 or 3; whether the observer was mistaken, or whether they really did see an 'extinct' species. And having criteria to help us determine into which category a potential sighting fits, and hence in deciding whether a follow-up of the report should be made, is essential.

As my only concern here is animals which are known to have existed in the recent past (though now widely believed to be extinct) the 9 criteria I shall outline here are substantially different to the criteria which would be used by, say, a cryptozoologist or a theist investigating reports of an angelic creature. Although there would obviously be severe overlap.

The Criteria

  • The report is consistent with what is known of the animal. This includes, if applicable, size, shape, movements, colour, markings, time of sighting, season, sex of the animal/s etc.
  • The observer's familiarity with the species. Whether the observer has seen the species previously and knows what it looks like, preferably while alive.
  • The conditions under which the sighting was made. The time of day (i.e. amount of light), the distance between the observer and the animal, the weather conditions, and the physical condition of the observer (including whether they had taken any hallucionogenic drugs in the lead up to the sighting).
  • Power of observation. Whether the observer is trained in a manner which would lead us to lend more weight to the credibility of their sighting. And whether the observer was aided by any optical instruments such as binoculars, a telescope, night-vision goggles etc.
  • Evidence of the animal. Whether indirect sign/s of the animal/s were seen, either just prior to the sighting or on a previous occasion.
  • Evidence of the sighting. Whether photographs, video footgae or audio recordings were made which may aid with identification of the animal/s.
  • The possibility of misidentification. Are there any animals (or inanimate objects) which the observer/s could have mistaken for the putatively extinct species?
  • The observer's vocabulary. Whether the observer has a sufficient vocabulary in order to convey the details of the sighting as accurately as possible.
  • Guilt. Whether the observer has a subconscious yearning for the species to still be alive to relieve the burden of guilt over their/our part in the extinction of the species in the first place.

These criteria should be consulted not just by those investigating reports of putatively extinct species, but the people actually making the reports as well. This would help to eliminate many cases of mistaken identity which would allow resources to be concentrated upon a core group of the sightings which have the most promise. A little elaboration on each of these criteria is therefore called for:

The report is consistent with what is known of the animal

If the observer attributes atypical behaviour to the animal then, depending upon how well known it is, that may completely discount the possibility of them really having seen the animal. Or it may merely make it more unlikely than not. But for species whose habits are wholly unknown no behaviour can be considered as atypical and hence this particular criterion does not apply in such cases. But caution must also be eased because if a species approaches extinction then inbreeding can result in all sorts of atypical or uncharacteristic behaviours which would otherwise lead to the report being dismissed out of hand.

The observer's familiarity with the species

If the observer has seen the species before, prior to its putative extinction, and preferably while alive, then misidentification is much more improbable relative to a situation where the observer only has a verbal description of the species to go by. Familiarity with a species does not in itself guarantee that any sighting must be genuine, and I have more to say about this below under the heading 'Pre-extinction sightings'. But if the observer is not only familiar with the species in question but also with any other species with which it could potentially be mistaken then their report has a lot of credibility.

The conditions under which the sighting was made

Conditions can dramatically affect the observational ability of an individual, especially if they are dehydrated, stressed, or starving. Weary desert wanders are apt to experience mirages after walking too many kilometres without sufficient water. The light factor can also affect the ability to perceive objects, especially at a distance, since they may appear indistinct or blurry, and hence increase the probability of misidentification or an ambiguous identification (i.e. a member of a genus, rather than a specific species).

Power of observation

If the observer is trained to visually intercept objects of varying distances, sizes, speeds etc. and can accurately report back on the nature of the object/s observed then we may add some weight to their report (if we have discounted intentional deceit). And if the observer is untrained in this manner then the accuracy of their report should not be considered as 100%.

Evidence of the animal

Animals often leave signs of their presence, which, being static, are more often encountered than the actual animal itself. When hunting man-eating tigers and leopards, as recounted in his books, Jim Corbett would use his jungle surroundings to his advantage, and to the disadvantage of his man-eating adversary. Although things such as hairs, footprints and scats can be misidentified, the ability to observe them for long periods, and to study them for some time, allows the observer to be more sure of the identification of the animal upon whose trail they are. And of course, if properly collected or preversed in-situ, can allow for a suitable expert to analyse the find.

Evidence of the sighting

In most instances the only evidence that a sighting actually took place is the testimony of the observer/s themselves, which can, as I have already pointed out, be quite innaccurate. Any photograph, for example, to accompany the report, especially if clear and unambiguous, can clarify the identification of the subject in the photo independently of the verbal description furnished by the observer/s, especially if identified by a recognized authority on the matter. And this can be important because there are actually two potential areas of weakness in an observer's report. The first is of course the potential for misidentification.

The possibility of misidentification

Whenever somebody reports having seen a recently extinct species, and a hoax is ruled out, the natural question to ask is "could they have been mistaken"? Many times the animal is glimpsed only momentarily which allows for a great deal of uncertainty, especially if the animal is similar in appearance to any extant species, and especially if they overlap geographically. But even if they do not overlap geographically, vagrant individuals, or individuals which escaped captivity, are both much more likely explanations than that the observer really did see an 'extinct' species.

The observer's vocabulary

The second area of potential weakness is the observer's vocabulary, or their ability to adequately represent/describe to others what they saw. This criterion may seem rather trivial but it is actually quite important in a lot of sightings. There are two links in the chain of reporting a sighting. The first of these goes from the actual source stimuli which caused the observer to have the sighting, normally an animal. And the second is either the verbal communication, or the written description, given to a third party. Both of these links create the possibility of misreporting, and hence both deserve serious attention.

Guilt

Although unlikely, it is conceivable that an observer will be subconsciously driven by guilt to see what they want to see. Namely, an individual of a species widely believed to be extinct so that they can satisfy themselves that it does indeed still exist. This may be because they feel guilty, either as an individual or on behalf of humanity as a whole, for the species' demise. Or it may be for another reason. Self-deception in humans is well known (Trivers, 2000), and therefore cannot be doubted. Any doubt over guilt causing a 'sighting' must be directed towards whether guilt is a sufficient criterion. And that will have to await further study.

Pre-extinction sightings

If sightings of a species (or subspecies) now known, or highly suspected to be, extinct are made prior to its putative extinction and within its generally accepted geographical limits then there is a tendency to take such reports at face value since many of the factors which count against observers making observations after the last unambiguous record of a taxon (as discussed above) do not count against such observers. However, the automatic acceptance of reports of a species known to have still existed at the time must be brought into question as such observers, as subjective beings, cannot by definition be infallible. And although some of the criteria listed above don't apply, others do. So that the possibility of misidentification is still too unreasonably high to simply accept at face value any pre-extinction report.

Tangible evidence

In rare cases, someone had a camera ready in anticipation. Or stumbled upon a clear trackway. Such tangible evidence dramatically increases the odds that the sighting will be either corroborated or dismissed, as agnosticism approaches untenability. Of course, evidence needs interpretation, it doesn't literally speak for itself (unless perhaps we had video of bigfoot, sasquatch, yeti etc., but those are not feared extinct). And those best able to squeeze as much information out of a print cast (or photo etc.) are qualified experts, who are invariably scientists. And a proper scientist is driven by discovery and the chance to overthrow the establishment, even without the incentive to achieve Nobel laureatehood.

Thus scientists are in the main excited by the possibility of contributing to verifying the continued existence of a putatively extinct species. Of course, it would be naïve in the extreme to think that every single scientist is a model citizen. As humans, scientists experience the gamut of human emotions and thoughts, motivations and agendas. There are unfortunately ample cases of scientists abusing their powers and privileges (e.g. Sabbagh, 1999). So that it is not merely a case of submitting evidence to an authority and receiving the report. There is an element of discernment as to which authority the evidence is sent to, or even whether one parts with the evidence in the first place.

There are sufficient cases of cryptozoologists sending off specimens, and either never hearing back or having evidence that the package never arrived at its intended destination3. And while claimed evidence of the yeti or Loch Ness monster is not directly relevant to the present article, nevertheless the protocol is largely the same: submission to experts. Thankfully such instances are very rare, and there is normally no such problems. Nevertheless, if one has had such issues in the past then one will tend to be sceptical of sending off specimens again. In such cases, it is best to conserve the evidence as best as possible until such time as one is confident enough that a reputable third-party is in a position to analyse the evidence.

That is not to suggest that non-scientists (i.e. interested amateurs) cannot competently analyse evidence. They certainly can. After all it is the knowledge itself and not a piece of paper which makes one truly qualified to analyse evidence. And scientists themselves clearly weren't born knowing what they do. They had to learn it too, by reading the same books and articles/papers that we all (hopefully) have access to. Nevertheless, science itself demands that certain protocols be met, which includes specific methodologies being followed, for example, to rule out contamination. Science's standards might be high, but they need to be. If we base our lives on science, then we better hope that the science actually stands up to scrutiny.

Conclusion

Just because a species has been officially declared extinct does not mean that it must therefore be extinct with no possibility of its survival whatsoever. There are probably lots of putatively extinct species which still survive, since it is quite clear from past cases of rediscovery that declarations of extinction are often premature, and in the case of the South Florida rainbow snake (Farancia erytrogramma seminola), purely armchair2. The problem is with the definition of 'extinction', and how stringent it needs to be. We cannot rule out a possible sighting of a putatively extinct species a priori unless there is literally no habitat left, and no chance of its existence in captivity. Barring those unlikely circumstances, each report needs to be considered (partially) on its own merits. We cannot afford to fall for the Romeo Error (Collar, 1998), and we cannot afford to let our biases dictate the outcome of any investigation into reports of 'recently extinct' species. Our personal opinion over whether the Thylacine still survives cannot influence our judgement of the soundness of any given report.

Notes:

1 Assuming that no significant bias in which sightings are reported exists. Otherwise, if sightings of species belonging to other taxonomic groups go largely unreported then the bias towards birds and mammals would be artificial.

http://www.biologicaldiversity.org/news/press_releases/2011/south-florida-rainbow-snake-11-22-2011.html

3 There is also the fact that expert 'analysis' can be knowingly false. Australian Cryptozoologist Mike Williams found this out for himself.

Bibliography:

Collar, N. J. (1998). Extinction by assumption; or, the Romeo error on Cebu. Oryx 32: 239-244.

Collinson, J. Martin. (2007). Video analysis of the escape flight of Pileated Woodpecker Dryocopus pileatus: does the Ivory-billed Woodpecker Campephilus principalis persist in continental North America? BMC Biology 5: 8.

Fuller, Errol. (2002). Dodo: From extinction to icon. London (UK): Collins. 192 pp.

IUCN. (2015). IUCN Red List of Threatened Species. Version 2015.1. <www.iucnredlist.org>. Downloaded on 15 February 2015.

Sabbagh, Karl. (1999). A Rum Affair: True Story of Botanical Fraud. London: Penguin. ix + 223 pp.

Trivers, Robert L. (2000). The elements of a scientific theory of self-deception. Annals of the New York Academy of Sciences 907: 114-131.

Wilcove, D. S. (2005). Rediscovery of the ivory-billed woodpecker. Science 308: 1422-1423.

Published on 21 September 2013. Updated 15 February 2015.