Popular Science Monthly/Volume 60/November 1901/The Story of the Cahow
|THE STORY OF THE CAHOW.|
THE MYSTERIOUS EXTINCT BIRD OF THE BERMUDAS.
By PROFESSOR A. E. VERRILL,
WHEN the Bermudas were first visited by Europeans, about three hundred years ago, they had never been occupied by man. In this respect they differed from most islands of a similar size and blessed with a genial climate.
The study of the character of their original fauna and flora and of the changes subsequently wrought by man is, therefore, of peculiar interest. Fortunately there were several educated and intelligent men in the two parties who were wrecked upon the islands (1593 and 1609) to whom we owe the first intelligent descriptions of the islands and their products. These writers and others who settled there in 1612 to 1616, all agree in respect to the wonderful abundance of certain seabirds, whose eggs and flesh contributed very largely to their food supply. Indeed, it is probable that without this source of food those shipwrecked parties would have died of starvation. Even later, in 1615, during a famine that occurred among the settlers, the birds furnished for a time a large part of their food. One of these abundant and useful birds they called the 'egg-bird,' because its spotted eggs were laid in vast numbers, openly, in May, on some of the smaller sandy islands 'reserved for their use.' This was undoubtedly a tern, probably the common tern, or the roseate tern, both of which were still breeding in small numbers on Gurnet Rock in 1850.
Perhaps both these species of terns were included under the general name of 'egg-birds,' for two or more species often breed together and have similar eggs. The noddy tern may also have been one of them, for it is mentioned under this name by one of the early writers.
But the terns were so continually and persistently robbed and killed that they were soon driven from their breeding grounds or exterminated. They are now known only as migrants. As breeding birds they have long been extinct at the Bermudas, the last records of their breeding being about fifty years ago. Among the formerly abundant birds there is one, however, of far greater interest; originally called the 'cahow' or 'cohowe,' with various other spellings, from its singular note. This bird is unknown to science and is, so far as known, totally extinct. At the time of the early settlements (1612 to 1615) it bred in great numbers on some of the smaller islands and was easily captured at night. It laid a single, large, white egg, described as like a hen's egg in size, color and flavor. The nest was, according to all early writers, except one, a burrow in the sand like a coney's, and not in crevices of the rocks, like that of the shearwaters, with which many writers have tried to identify it. Governor Nathaniel Butler, in his 'Historye of the Bermudaes,' writing about 1619, states that its eggs and young were found in crevices of the ledges, but he probably did not have the advantage of personal experience.
The time of laying its eggs is another very remarkable thing, in which it differed from all other birds of northern latitudes. The early contemporary writers all agree that it laid its eggs 'in December and January' or 'in the coldest and darkest months of the year.' The shearwaters, even in the West Indies, lay their eggs in spring (March
and April) and their eggs are so musky that they are not edible; certainly no one would compare them to a hen's egg. Their flesh has, also, so strong a flavor of bad fish-oil and musk that no one would eat it, unless on the verge of starvation.
The bird itself was variously described as of the size of a pigeon, green plover or sea mew; its bill was hooked and strong, and it could bite viciously; its back was 'russet brown' and there were russet and white quill feathers in its wings; its belly was white. It was strictly nocturnal in its habits, and could be called within reach of the hand by making loud vocal notes. Its flesh was described as of excellent flavor, and for that reason it was captured at night in large numbers, while its eggs were constantly gathered for food. It arrived in October and remained until the first of June.
There is no known living bird that agrees with it in these several characters. Most certainly it could not have been a shearwater, nor any member of the petrel family, all of which have such a disagreeable flavor that neither their flesh nor eggs are edible. It seems to me far more probable that it was allied to the auks (Alcidæ), many of which burrow in the ground and lay white, edible eggs. The northern auks also have edible flesh and often a strong hooked bill.
But no existing species breeds so far south, nor do they breed in winter. The cahow may have spent the summer in the southern hemisphere, but possibly it was an arctic bird that produced a southern brood in winter. Or it may have been a localized pelagic species, coming to the land only for breeding purposes.
The following graphic account of the bird and its habits was written by Mr, W. Strachy, one of the party of 150 persons who were wrecked with Sir George Somers in the 'Sea Venture,' July, 1609:
The following description is taken from 'The Narrative' (1610), by Silvanus Jourdain, who was also one of Somers's party:
In a letter written from the 'Summer Islands' Dec., 1614, by the Rev. Lewis Hughes, the following account of the cahow occurs:
This is the only account that gives the time of its arrival and departure.
The following extract is from Governor Butler's 'Historye,' written about 1619:
This is the only original statement that I find, among the early writings, that it lives in holes of rocks. It is possible, however, that it lived in all available holes, either in those made in the soil by the abundant land crabs or those found among rocks. It may not have made its own burrows, when other holes were available. Captain John Smith's account was compiled from those given above. He did not visit Bermuda.
There are several references to this bird in the local laws of Bermuda. Even so early as 1616 a law was passed restricting the taking of the bird and its eggs, because of the rapid decrease in its numbers.
It is thus referred to in Governor Butler's 'Historye.'
Among the laws enacted by the Bermuda Company, 1621-32, was the following:
This doubtless refers to the egg-birds as well as to the cahow. It seems to have been almost or quite forgotten for over 200 years. In 1849, Mr. J. L. Hurdis visited Gurnet Rock or 'Gurnet Head Rock' a small, precipitous, and nearly inaccessible outlying island, situated off Castle Harbor, and found there the nests of a shearwater in the crevices of the rocks. He concluded that he had found and identified the long lost cahow.
His identification has been accepted by Capt. S. G. Reid and other later writers on the ornithology of the Bermudas, apparently without any adequate consideration of the facts stated by the early writers from personal observation. It has been assumed by nearly all recent writers, though without any real evidence, that Gurnet (Head)
Rock was the particular place, or at least one of the places, where the cahow bred In old times. Perhaps this may be due to the name, but it was called 'Gurnet Head Rock,' because it lies off 'Gurnet Head' on Castle Island. The latter name was in use in 1619. Some of the early writers say that it bred on some of the smaller uninhabited islands, inaccessible to the wild hogs, without designating any particular one (see Strachy's narrative). Governor Butler and the Rev.. Lewis Hughes say that a boat could go to its breeding places and get a load of the bird and its eggs in a short time (see Strachy's account, above). This was apparently done only in the night. Therefore the islands visited must haw been near at hand and easily accessible, with available and safe landings, even in winter, when the eggs were sought. Gurnet Rock does not fulfill any of these conditions. It is several miles from St. George's, then the chief settlement and capital; it stands isolated outside all the other islands, so that it is exposed to the full force of the sea on all sides and in December and January the sea is always boisterous in these waters; it has no place where a boat can safely land, unless in nearly calm weather and by daylight; its sides are nearly perpendicular, exceeding rough, high cliffs, which can hardly be scaled without risk of loss of life or limbs, unless by means of ropes and ladders. Moreover the top is of very small area and almost destitute of soil. So that there is no possible chance for a bird like the cahow to burrow there. The writer, with two companions, visited this island about the first of May of this year, on a day when the sea was not very rough, and the tide was low. We found it impossible to land except by stepping out upon a narrow, slippery and treacherous reef of rotten rock and corallines, covered with sea-weeds, exposed only at low tide, and standing a little away from the shore, with deep water between. The sea was breaking over this reef, and it was difficult to wade ashore except at one place, on account of the depth of water. With the aid of a long pole I climbed partly up the side of the rock, at the only available place, and though I did not reach the summit, I could, from my highest position, see that there is no soil on the top, but only a few seaside shrubs and herbaceous plants, growing from crevices of the rock. This was sufficient to convince me that the cahow never bred on this rock, and, if it had, the early settlers would never have gone there in the winter and at night to get the eggs or birds.It is far more probable that one of its breeding places was on Goat Island, which is a larger, uninhabited island about half a mile inside of Gurnet Rock, and with a beach of shell-sand on the inner side, where boats can safely land. Moreover on this island, in early times, there was a deep deposit of sand and soil, which was subsequently used as a burial place for soldiers who died in the old fortifications on this and the adjacent Castle Island and Southampton Island. Indeed we found two ancient human skeletons partly exposed in this bank of sand, where it had been recently undermined by the sea. Evidently a large amount of this sandy deposit, which contains fossil land snails, has been washed away since the time when the old 'Charles Fort' was built upon this island, about 1615. This old ruined fort was of small size and apparently has been abandoned since about 1630. It has the same size and form shown on Norwood's chart, published in 1626. Norwood mentions, in 1663, that it had then 'fallen into decay.' Probably the cahow may have bred also on Castle Island, which is a larger island a short distance inside Goat Island, and on Southampton Island,
Gurnet's Head of Castle Island, showing profile at a; b, Southampton Island and ruins of the fort, built bout 1620; c, entrance to Castle Harbor.
Goat Island (formerly Charles' Island), with ruins of Charles' Fort, built about 1615.
a little farther west. But these and other adjacent islands, including Cooper's Island, were fortified between 1612 and 1620, and it is probable that their occupation, at that time and later, was one of the causes of the rapid extermination of the cahow and egg-birds. We endeavored to secure some bones of the cahow by digging in the rubbish heaps about the old forts on Castle Island, but though we found numerous bones of fishes, hogs, etc., and a few of birds, none appear to belong to the cahow. But probably the deposits that we excavated were of later date, for the Castle Island forts were again garrisoned during the war of 1812. We found old silver and brass military buttons, gun flints and the cores of flint nodules, from which they had been chipped, with many other old relics, but nothing to indicate the first period of occupation, from 1614 to 1625, when alone the cahow might have formed a part of the rations.
In the 'Plain and True Relation' by the Rev. Lewis Hughes, 1621, there is a graphic account of the famine of 1615, from which the following extract is taken:
This account of the habits of the cahow would not, in the least, apply to the shearwater. It is probable, however, that the latter is identical with the nocturnal bird called 'Pimlico' by the early settlers.
The following extract from the 'Historye' by Governor Nathaniel Butler, written about 1619, relates to the famine of 1615, and shows some of the causes of the very rapid extermination of the birds:
The chances of finding bones of the cahow would probably be better on Cooper's Island than elsewhere, if the above narratives of Governor Butler and Mr. Hughes were correct. That the latter referred to the cahow, though he did not mention the name of the 'silly birds,' may be properly inferred, because of the season, 'beginning of the newe yeare,' when the large party of starving settlers was sent there for food. The egg-birds did not arrive until the first of May. This famine and the sending of a large number of starving persons to feed on the defenceless birds, at their breeding season, was unquestionably the direct and principal cause of their rapid extermination, for it was during the very next year (1616) that the first law was passed, 'but overlate,' restricting the 'spoyle and havock of the cahowes.' We were unable, for lack of time, to dig for the bones of the cahow on Cooper's Island. The loose ground there is full of the holes of two species of large land crabs. Such holes may have served the cahow for nesting places.