QUESTIONS AND ANSWERS?
Having reviewed some of the witness accounts of long necked Sea Serpents, it may have become strikingly clear to the reader, that a seal with a long neck would offer a good solution as to their identity. However, up to recently there are two common arguments put forward, against the existence of such a creature. These are that firstly there was no evidence to suggest that a species of pinniped from the past or present, had ever evolved a neck comparable to that of witness descriptions and secondly that if such a creature did exist, being a pinniped it would be tied to land and hence therefore discovered by now.
However, with regard to the first proposed pitfall, in the early 1980s, two new species of fossil pinniped were discovered in South America which appear to come close to such an identity.1 Apparently belonging to the phocid family and dating from the Pliocene, these seals were characterised by their elongated necks. Although there appears to be little available information with regard to them outside of academic circles the species acrophoca longirostris has been termed a `swan necked seal`. Although in reality these would not be comparable to those of plesiosaurs, they are significantly longer than the necks in presently known pinnipeds. What is more there appear to be other as of yet undescribed members of the genus which may prove to share similar or more pronounced features. In fact one, acrophoca piscophoca, apparently has an even longer head and neck.
The size of both these animals appears to be generally consistent with presently known species of pinniped and it was originally proposed that both were related to the modern leopard seal although there is a school of thought that places them closer to the monk and elephant seals.2
So with regard to a seal having evolved a long neck there is at least some tentative proof to show that two species of apparently extinct pinniped appear to have done just that.
If these pinnipeds managed to survive to the present day, or the feature was adopted by a similar group of pinnipeds then such a feature must have some evolutionary use.
Reconstruction of Acrophoca Longirostris , D. Naish.
The second argument against such an animal surviving without modern detection, however, needs to be addressed.
In the next few pages I will attempt to offer speculative ideas, based on information known about existing pinnipeds to deal with both these arguments and attempt to describe a theoretical natural history of such an animal.
When people think of a long neck they may inevitably think of a giraffe or Plesiosaur both of which have been used to describe sea serpents. The giraffe of course uses its long neck to feed on the leaves of tall trees, while the plesiosaur used its neck to catch fish and possibly pluck things from the sky. In both these cases the neck is used in the primary need of any animal, to obtain food.
Unlike the ceteaceans, whose necks have become compressed and fused for their aquatic adaption, the necks of pinnipeds are extremely flexible and when this attribute is combined with their swimming ability, they become fast, efficient predators. As well as krill, squid and fish, the diet of pinnipeds may also be supplemented by predation on birds and other small animals. Although not fully assessed in most species it is common in the Northern fur seal and unquestionably voracious in the leopard seal. Indeed the leopard seal is known to regularly gorge itself on penguins and other avian prey as well as other species of seal.
As we have already seen, it is also known for its very reptilian appearance and sinuous neck, which it actually uses in predation by coiling it back and striking at its prey like a snake. This method of predation seems to be similar to how it is thought that the plesiosaur must have hunted, by `darting` its neck out at passing fish.
In fact Heuvelmans suggested that a seal with a long neck might have evolved to feel the niche left by the plesiosaur and its kin and given the descriptions of the leopard seal, it is not hard to accept such likelihood. So theoretically at least then, a seal with a long neck may gain some advantage in predation, especially if it was able to conserve vital energy by utilising such an asset, (something that I will speculate on later). However, a long neck would not have appeared overnight and would have had to evolve in response to a particular environmental need or function.
Now although otariids use their necks in locomotion, both on land and in the sea, a very long neck would surely hinder underwater efficiency in such an animal, as the ideal underwater form is a cigar shape, slightly tapering at both ends. As already mentioned the cetaceans have compressed necks, which provide them with a streamlined shape, and when phocid seals swim they tend to `telescope` their necks, thus shortening their bodies and reducing underwater drag. Now I will not even attempt to take on underwater dynamics, as I am poorly qualified to do so, suffice to say that both the plesiosaur and apparently acrophoca longirostris, however well they swam, had elongated necks.
There are a few other areas that I would like to explore concerning the possible use of a long neck, although again I am not qualified to do so. I have included them in the hope that may inspire further discussion.
The first of these concerns thermoregulation, or the regulation of body heat. As seals are well insulated by fur and blubber, when the climate becomes warmer they may suffer from a form of heat stress. A common way of relieving such stress, for instance on land, is to rest in tide pools or seek rocky shelter. They also have a unique ability found in some marine mammals in that they can divert warm blood into their flippers, due to the close proximity of both veins and arteries in their bodies and the flippers can then be dipped in water or waved in the air to cool off, (seals cannot sweat like humans, although the Northern fur seal can pant like a dog).
Likewise, when pinnipeds need to conserve heat, species such as the California sea lion may adopt a `jugging` position in the water whereby their flippers are displayed on the surface of the water.
The animal will rest with one of its fore flippers and both of its hind flippers above the surface in a sort of basking position.
Would therefore such an extremity as a long neck, with the relevant type of circulatory properties, fulfil a similar function? For instance the seal could simply rest its head above the water to conserve or lose heat, and it is interesting to recall Mackintosh Bell’s friends, alluding to the fact that the creature was seen when the weather was hot.
Other points to possibly contemplate with regard to this feature are whether the long neck provides some mechanism whereby the seal can retain a greater oxygen carrying capacity that may allow it to dive for longer periods or stay submerged longer. Elephant seals have stomach sinuses that allow them to store more blood to do just this.2
Or could it also incorporate a biological structure which also allows a unique surfacing and submerging capability that may explain why many reports of sea serpents comment on the ability of such creatures to “sink” straight down? Possibly some structure akin to the pharyngeal pouches found in the walrus?
And what are we to make of the Storsjo animals extending appendages? Although this account is difficult to make sense of and I am not convinced by Heuvelmans assertion of `snorkels`, which he envisioned would function by allowing his animal to breathe without surfacing fully, there is some relevance for the idea in the pinniped kingdom. As well as helping such a creature to breathe without surfacing fully while swimming, such an adaption may be of benefit in other ways. Seals such as the northern fur seal spend long times at sea and must therefore sleep in the water. When sufficient hauling out ground is not available, other species such as the harbour seal, take on a vertical position in the water whereby their body remains submerged, but their head pokes out above the surface. The elephant seal, the largest of the pinnipeds, has also been observed in this position and the walrus as already recounted as buoyancy pouches which allow it to sleep afloat.
So a long neck, equipped with Heuvelmans snorkels, may provide a novel method of not only breathing while swimming, but also breathing while sleeping and in both cases, reduce the need for being observed, also a good ploy in predation. Such breathing tubes are unknown in present pinnipeds, but two species, the elephant seal and the hooded seal, already have nasal protuberances.
The male elephant seal has its weird looking inflatable proboscis, while the male hooded seal (Cystophora cristata) can actually inflate a red, membranous sac, from its left nostril, (surreal indeed).
These unworldly assets fulfill roles in sexual and territorial display in both animals while in the elephant seal the proboscis helps in the conservation of water. In both cases such adaptive strangeness is only found in the males of the species. So although not impossible, such snorkels would be unlikely.
Still, it is worth imagining, a seal with a long neck, sitting submerged on a shallow tidal shelf, resting or sleeping with its head and neck barely touching the surface of the water, breathing silently through its snorkels while waiting for a tasty bird to set down on some nearby rocks.
After all, nature does provide many novel methods of survival for her creations.
Although some species of seal may spend up to ten months at sea, they must all presently return to land for the purpose of moulting, breeding (although copulation may occur on land or in the water), resting and giving birth. Such hauling out time varies between species and depends on a number of factors including available space, site fidelity and the foraging patterns of individual species.
Moulting which is more pronounced and exhaustive in phocids, requires a great deal of energy expenditure and need for rest. However, the Northern fur seal (Callorhinus ursinus) may take up to three years to fully achieve its moult, a time when it is not tied to land.
Although Heuvelmans quotes Victor B. Scheffer as saying that an occasional walrus or phocid may be born in the sea and survive, aquatic birth in pinnipeds as a rule does not occur. Phocids are probably evolving towards this practice, as their pup dependency may last for as little as four weeks and this adaption would presumably be the next evolutionary step for their species.
Heuvelmans, to help his theory along, opted for a species of pinniped that had overcome this need, but before we go on to discuss this notion it is worth looking at some other, already practiced strategies.
Pinniped birth in most species is well understood, although it seems that little is known about the reproductive behaviour of the leopard seal and few leopard seal pups have ever been seen, (despite the fact that there are approximately 220,000 Leopard Seals thought to be in existence).
In general a female seal, will usually mate a few weeks after giving birth, the resulting implantation and gestation periods being delayed for up to eleven months, until the same time the following year when the seal will give birth again. Seals usually give birth to a single pup and as we have seen, weaning may take a short time in phocids, but longer in the other two families. Lactation in phocids can last from 4-50 days while in otariids and odobenids it can last from 4-36 months, although female walruses will apparently take their pups with them when foraging.
Some harbour seal females (Phoca vitulina), congregate in shallow water or along sandbanks to give birth and their pups are born with a sea going pelt. If the need arises they are capable of following their mother into the water five minutes after birth. The hooded seal meanwhile has the shortest weaning period of any mammal, four days.
Arctic ringed seals (Phoca hispida) breed in solitary family groups, with an adult male, female and pup comprising one unit while some pinnipeds, such as the lake living Baikal seal ( Phoca sibirica) and the ringed Seal, give birth and raise their young in ice caves which act as secure environments.
There are of course many caves the world over and it is clear that in certain parts of the world, for instance around Great Britain, that caves, usually inaccessible to man, play an expanded role in the life of the native pinnipeds for various purposes.
The rarest of all presently known seals, Mediterranean monk seals (Monachus monachus), spend much of their time in and around such caves, usually with submerged entrances. They use the shallow waters around them as a learning ground and kindergarten for their pups to swim thus in relative safety from the surrounding environment.
The Hawaiian monk seal (Monachus shauinslandi), whose skeletal structure has remained the same for 15 million years and is endemic to the islands, which give them its name, only number between 1300-1500 animals. They are also solitary and are rarely found in groups preferring remote atolls away from humans.
Similarly, not much is known about the breeding distribution of the grey seals (Halichoerus grypus) that inhabit Iceland, except that they appear to breed in caves.
What is more, it is only when an abundant species of seal hauls out, that we see the familiar sights of crowded, interactive hordes as typified by the elephant seals and sea lions, but not all species of seal are abundant. As we have already seen, the Caribbean monk seal is thought to be extinct, while at present there are thought to be somewhere in the region of 500 Mediterranean monk seals, 1500 Hawaiian monk seals and 2500 Guadalupe fur seals (Arctocephalus townsendii) in existence.
In comparison there are approximately 145,000 California sea lions (Zalophus californianus), 550-750,000 Southern elephant seals and over a million Northern fur seals. Logically then, we could presume that if our seal exists, it is rare and if it has adopted for instance a cave rearing and birthing strategy, then instances of hauling out may be few and far between as well as remote. In fact considering the amount of sea serpents seen over the years, there may have been more sightings of such creatures than there are long necked pinnipeds existing.
There is also of course the question of survival. First year survival in British grey seals, which are abundant, is low with only 54% of females surviving to breed. A rare long necked pinniped species could therefore similarly lose half of its number in the first year adding to its rarity. On top of this there is also the potential effect of disease on any population. Although in UK waters there are probably few natural predators of such a creature if it does exist in other areas of the world this may be more common.
Alternatively, we can opt for Heuvelmans notion of aquatic birth, which would make the existence of such a creature easier to conceal. In support of this theory it is worth noting that a similar species of mammal, the sea otter (Enhydra lutris), has already managed this. The sea otter is a relatively new animal species, having evolved to its present form within the last 5-7 million years, a much shorter time than the pinnipeds. In spite of this fact though, it has managed to eclipse them, as it is able to give birth on land or in the sea.
So theoretically then, a recently evolved species of pinniped could have reached a similar advancement.
Whether any of this is correct or not, hopefully the reader will begin to appreciate that there is some scope for the possibility that a, rare pinniped that has evolved or adopted some of the strategies already practised within its kind, may not be as observable as one would expect.
In the following pages, I would like to expand some of this speculation further possibly wildly, in an attempt to produce a speculative natural history of such an animal.
1According to scientific principle the fineness ratio is used to predict the effect of underwater drag on a body shape. It is calculated by dividing the length of the swimming object by the width at its widest part. Marine mammals exhibit a value from 3-7 although 4.5 is considered the most effective.
If we take Mackintosh Bells animal then with a reported length of 20 ft. and a width of 4-5 ft at is broadest we end up with just such a value, 4-5. Whether a long neck reduces this coefficient is another matter and one that I am not qualified to explore.
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