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New light on an old tortoise - Gilbert White's Selborne tortoise re-discovered.

A C Highfield & J. Martin

TESTUDO WHITEI BENNETT 1836

SUMMARY

N. African members of the genus Testudo have in recent years all been regarded as belonging to the same species, Testudo graeca L. 1758. This paper describes a form which occurs in Algeria, geographically immediately adjacent to the race recognised as T. graeca L. 1758, but which demonstrates sufficient divergence of characters to require separate classification as an autonomous species. Indeed, it has so been described previously (Bennett, 1836), but in subsequent revisions of the genus (Wermuth and Mertens 1961, Loveridge and Williams, 1957) has been erroneously relegated as a synonym of T. graeca L., Testudo ibera (Syn. T. graeca L., Boulenger 1889) or of Testudo marginata SCHOEPFF 1792 (Gray 1870). The object of this present paper is to demonstrate that its earlier status as a separate species was justified and should therefore be restored.

KEYWORDS: Testudo graeca - Gilbert White - Algeria - Taxonomy - Size - Age - Nomenclature

INTRODUCTION

The Testudo graeca of Linnaeus (1758) is based upon the holotype of Edwards (1748) (Terra typica = Santa Cruz, Oran, Algeria). An excellent illustration of this carapace is provided by Edwards (1748) P.204. Synonyms are proliferate, good summaries of which are provided by Loveridge & Williams (1957), Siebenrock (1910), Strauch (1862) and Boulenger (1891). It should be noted that many illustrations purporting to show T. graeca L. 1758 actually depict other races;- two such examples are Sowerby & Lear's plate (1872) which although labeled Testudo graeca is unmistakably that of a Testudo ibera PALLAS 1814 and Lortet's (1888) fine plate of a Testudo hermanni GMELIN 1789 which is mis-titled Testudo graeca L.
Most published descriptions of land tortoises in Algeria are unfortunately rather unsatisfactory. Compound descriptions are particularly commonplace, with regular confusion between the race T. graeca L. 1758 , T. ibera PALLAS 1814, T. marginata SCHOEPFF 1792 and T. hermanni GMELIN 1789 which was habitually referred to as T. graeca L. by many authors of the period. Few 19th century authors were sufficiently familiar with the true diagnostic characters of these various races and both synonyms and composite descriptions are therefore endemic in their writings e.g, see Gervais (1836, 1848 and 1857), Strauch (1862), Doumergue (1904) Tristram (1860) and Lataste (1880 and 1881).
Geographically erroneous reports of T. marginata in Algeria may however have significance in the light of our present findings. It seems quite possible that the basis of these reported sightings could have been the large Testudo spp. described and illustrated here. These must have been encountered in the field, but seem to have been explained as simply elderly specimens of T. graeca L. which had attained an unusual size e.g, writing of Testudo graeca Boulenger (1891) comments;

"Old specimens have been taken for the allied T. marginata Shoepff, s. (syn) campanulata STRAUCH (by Gervais and Lallemant), the habit of which appears to be restricted to Greece".

This question of confusion regarding the distribution of T. marginata is also discussed by Lortet (1888) who states that he received many reports of marginata from Algeria, but felt that they were not accurate, being based upon specimens of T. ibera PALLAS (syn. T. mauritanica Dumeril et Bibron) which may "possess similar characters" (p.9). It should be noted that M. Lortet's usage of T. ibera PALLAS is itself synonymous with Testudo graeca L. as is Dumeril and Bibron's Testudo mauritanica (Dumeril and Bibron, 1835).

Gilbert White's "Timothy" Tortoise of Selborne

Readers of Whites classic work The Natural History of Selborne (1789) cannot fail to have been entertained by his vivid descriptions of the activities of the "old Sussex tortoise" which passed to him following the death of his aunt in 1780. It had been purchased by his uncle Mr. Snooke from a sailor in Chichester for 2/6d sometime during 1740. White knew the tortoise prior to obtaining possession of it from his many visits to his relatives who resided at Delves House, Ringmer, where the animal lived (Wright, 1917). As White explains in one of his letters to Daines Barrington dated 8th October 1770;

" A land tortoise, which has been kept for thirty years in a little walled court belonging to the house where I am now visiting, retires under the ground about the middle of November, and comes forth again about the middle of April. When it first appears in the spring it discovers very little inclination towards food; but in the height of summer grows voracious: and then as the summer declines its appetite declines; so that for the last six weeks in autumn it hardly eats at all. Milky plants such as lettuces, dandelions, sowthistles are its favorite dish. In a neighboring village one was kept till by tradition it was supposed to be an hundred years old. An instance of vast longevity in such a poor reptile!".

Another letter dated 21st April 1780 continues;

"The old Sussex tortoise, that I have mentioned to you so often, is become my property. I dug it out of its winter dormitory in March last, when it was enough awakened to express its resentments by hissing; and, packing it in a box with earth, carried it eighty miles in post-chaises.... as it will now be under my eye, I shall now have an opportunity of enlarging my observations on its mode of life, and propensities".

This White certainly did, recording assiduously the behaviour of "Timothy" until a few days before he died in 1793. A collection of Whites notes concerning the tortoise has since been published separately (Warner, 1946). An excellent summary of Gilbert White's involvement with 'Timothy' tortoise and a brief history of Selborne can also be found 'Selborne and the Tortoise Connection' (Chatfield, 1986).
Of precise data concerning White's companion we have some useful records. We note that over the 18 years White had charge of it, its weight fluctuated between 2,835g to 3,260g. Its carapace (which is now preserved in the British Museum collection) measures 250mm. White himself did not realise that it was a female, nor did he know its origin, for he speculates that it may have come from Virginia, U.S.A. He did, however make a reasonable guess at what it might have been;

"Timothy seems to be the Testudo graeca of Linnaeus" (Journal of Gilbert White, July 1st 1780).

White's confusion in respect of Virginia may well have some foundation in the fact that his aunt, Mrs. Snooke, also kept Box Tortoises (Terrapene spp.) which originate in the U.S.A.

The Torquay Tortoises

Flower (1945) reported in some detail on a pair of female tortoises of Algerian descent which were subsequently maintained in captivity in England for 39 years. Flowers excellent report, based upon records kept by their owner, a Mr. Moysey of Torquay, chronicles the growth of the pair from 1906-7 when they weighed and measured 0.012kg/49mm and 0.008kg/47mm (measured over the curve of the carapace) respectively to 1944 when their measurements were 3.969kg/365mm and 1.814/279mm. A further set of data on the same tortoises was presented by Loveridge and Williams (1957) where it is recorded that as of September 1st 1955 the tortoises weighed 2.629kg/298mm and 4.252kg/365mm and by F. E. Moysey (1962). The largest of the pair died in 1969 at the age of 63 years having attained a maximum weight of 4.366kg (Lambert, 1982).

The parents of these tortoises were collected in the Foret de Bainen a few kilometers west of Algiers. Eggs were laid during May 1905, and from the 14 hatchlings "Daimler" and "Panhard" were eventually selected and bought to England. The illustration accompanying Flowers report clearly identifies them as belonging to the same race as the specimens in plate 1 and not as T. graeca L. 1758 as Flowers believed. Flowers was however correct in his conclusion that "very large" tortoises "do not necessarily come from Syria, Asia Minor, or the Balkan Peninsular, but may be from the typical Linnean locality of north-west Africa."

The claim that this form of Algerian Testudo, as depicted by Flower (1945) are comprised of nothing more than extremely old or unusually large T. graeca L. is not supported by the evidence.
This form, henceforth referred to as Testudo whitei BENNETT 1836, consistently exhibits entirely different carapace markings from T. graeca L.
Both T. graeca L. and T. whitei attain full adult dimensions at approximately the same age, typically between 25-35 years of age. Testudo whitei however consistently and invariably attains a much greater size than that ever recorded for specimens conforming to the holotype of T. graeca L. After approximately 40 years of age, growth in both forms slows very considerably eventually becoming almost imperceptible.

The plastral markings of the two races are consistently different.

The general carapace morphology of T. whitei is quite different from that of T. graeca L. with each race demonstrating an entirely different height-length ratio.

COMPARISON OF CHARACTERS

Carapace markings: T. graeca L. 1758

Groundcolour amber-yellow to greenish-yellow, dark brown to black central dot on vertebral and costal scutes, vertebral and costal scutes feature distinctive brown-black lateral "ring" marking, the central marginal scutes feature a distinctive brown-black triangular "saw-tooth" pattern. The plastron typically features 3 pairs of large brown-black dots (plate 2).

Carapace markings: Testudo whitei BENNETT 1836

Groundcolour light amber-yellow, less distinctive central brown- black markings on vertebrals and costals, sometimes entirely absent. No lateral "ring" markings, very distinctive medullary "ray" pattern radiating from areolae on vertebral and costal scutes usually present. Some specimens exhibit fewer markings on an almost unbroken even yellow-amber ground colour. The characteristic dark brown-black triangular marginal markings of T. graeca L. are invariably either absent entirely or ill defined compared to T. graeca L. The plastron features a larger and more diffuse expanse of black markings than T. graeca L. (plate 3).

Carapace morphology and size: T. graeca L. 1758

The following measurements were taken from six randomly selected adult females conforming to the holotype of T. graeca L. as illustrated in plates 4 & 5. The age range of the individual animals was estimated at between 35 years to 85 years. Some specimens had been in captivity in England for over 60 years.

Length Carapace height Maximum width Weight
192mm 104mm 138mm 1,500g
190mm 99mm 133mm 1,250g
187mm 105mm 135mm 1,300g
176mm 94mm 125mm 1,000g
165mm 95mm 119mm 800g
153mm 84mm 109mm 790g

The specimen at 192mm is the largest female example of this race measured to date.


Carapace morphology and size : Testudo whitei

The following series of measurements were obtained from eight adult Algerian females conforming to the type of T. whitei and examined recently by the authors (plates 1 and 6). The age range of the animals was estimated at between 35 years to 85 years. The specimen measuring 270mm was known to be less than 40 years of age with reasonable certainty, having been in captivity for over 30 years and from a time when it measured less than 70mm long.

Length Carapace height Maximum width Weight
280mm 134mm 182mm 3,750g
280mm 125mm 190mm 3,575g
272mm 127mm 130mm 3,400g
270mm 130mm 180mm 2,875g
268mm 135mm 180mm 3,300g
250mm 125mm 190mm 3,000g
245mm 120mm 165mm 2,600g
240mm 118mm 165mm 2,200g


Comparative morphology female T. graeca L. vs. T. whitei BENNETT

Apart from the obvious difference in maximum dimensions and body mass, if a length-height index is prepared by dividing the straight line carapace length by the maximum carapace height the difference in body shape is also evident, the female T. graeca L. having a relatively higher domed carapace than those of T. whitei BENNETT which are broader and flatter. The indices obtained from the eight examples of T. whitei described above are 2.09, 2.24, 2.14, 2.08, 1.99, 2.00, 2.03 and 2.04. If the same formulae is applied to the six female T. graeca L. the results are; 1.85, 1.92, 1.78, 1.74, 1.87 and 1.82 - an altogether lower average index for the race which is consistent across all examples examined to date.
Whilst these measurements were being made, it was further observed that female specimens of T. graeca L. generally exhibited a much wider posterior marginal flare than the measurement of the width of the body at the median line. This character is not typical of Testudo whitei, where the median carapace width of females often is equal to or exceeds the maximum lateral width attained by the posterior marginals. In only one of the eight specimens of T. whitei detailed above was the posterior marginal maximum width greater than that of the body at the transverse median line (the specimen measuring 272mm) and in this case it was noted that the tortoise was unusually elongate and narrow in form. The median width was 125mm, yet the maximum marginal width was recorded at 164mm. This latter measurement is not unusual, but the narrowness of the waist in this specimen in our experience is most unusual. In all other respects the specimen was absolutely normal.

Sexual dimorphism male Testudo graeca L. & Testudo whitei BENNETT

The males of both species attain considerably smaller dimensions than the females. The dimensions of the two largest specimens of each race we have seen to date are as follows;

Testudo whitei BENNETT 1836
Length Carapace height Maximum width Weight
240mm 111mm 154mm 2,350g
Length-Height ratio = 2.18

Testudo graeca L. 1758
Length Carapace height Maximum width Weight
188mm 102mm 118mm 1,150g
Length-Height ratio = 1.84

Most specimens are much smaller than this, the two above tortoises being unusually large and somewhat exceptional examples of their respective species. The different H-L ratios express the lower domed and much more elongate carapace of males belonging to the race T. whitei compared to males of T. graeca L. The following tables provide typical comparative length-weight data for males of the two species;

Testudo graeca L. Testudo whitei BENNETT
Length Weight Length Weight
155mm 750g 223mm 2,200g
145mm 675g 215mm 1,750g
160mm 800g 220mm 2,000g

It will be noted that males of T. whitei typically weigh over 1kg more than males of T. graeca L. The figures of weights and lengths obtained from males should be compared to the data taken from females. In both races, males are typically considerably smaller than females with a lower body mass and H-L ratio representing the reduced 'dome' or carapace curvature.

Comparison of thigh tubercles; T. graeca vs. T. whitei

There is a considerable difference in the construction of the thigh tubercles of the two species. Those of specimens conforming to the holotype of T. graeca L. are smaller, and typically do not extend beyond 2.5mm from the surface. Those of T. whitei BENNETT are whitish in colour and typically extend in an inwardly curved direction (towards the cloaca) as much as 7mm from the surface of the skin, having sharply pointed ends. This form of thigh tubercle has not been observed in any specimen conforming to the Linnaean holotype, but is consistently found in T. whitei BENNETT (see plates 7 and 8).

Original publication

In the 1836 edition of Whites "The Natural History of Selborne" the editor, Bennett, added the following footnote to letter L of 1781 concerning "the old Sussex tortoise" (p.360 - 361);

"Interesting as the old family tortoise has been rendered by the anecdotes related of him by Gilbert White, his history may be closed by the statement that his life was not prolonged much beyond that of his protector. He died, it is believed, in the spring of 1794; after an existence extended in England to about fifty-four years, the last fourteen of which were spent at Selborne. The thick shell, in which he was coffined while alive, is preserved in the residence of the master who secured for him an enduring existence in the memories of many. My friend Mr. Bell regards the specimen, which he has had an opportunity of inspecting, as an old and worn shell of the bordered tortoise, Test. marginata, SCHOEPFF: and all who are acquainted with the extent and accuracy of his knowledge of the Testudinata, must be aware that anyone who differs from him on such a subject, is probably in the wrong. Yet at this risk I have ventured to regard the Selborne tortoise as a distinct species. Its shell is less elevated than is usual in the bordered tortoise, once named on that account the bell-shaped: its wrinkles are less strongly marked and less sharp: its sub-caudal plates form with each other a much more open angle: and its anterior supra-femoral plate, instead of running to a point towards the back, has an inner margin nearly of equal length with its anterior and posterior edges. But the general form of the shell of a tortoise, the sculpture of its surface, and the shape of particular plates, are all too variable in many species to warrant the adoption of any or all of these characters as absolutely distinctive; and on them no assured reliance can consequently be placed. More stress may be laid on the animal, and on particular organs or plates attached to its body; and in the case of Gilbert White's tortoise there is a fragment remaining of the skin of one of the thighs which principally induces me to regard it as distinct from the bordered species: for on this fragment of skin there is a large white conical process or spur. No such process was noted by Mr. Bell on the specimen of the bordered tortoise which he had alive and which is beautifully figured in his splendid work on the Testudinata: evidence, it is true, of a negative character only, but becoming positive when taken in conjunction with the distinct statement of M. Bibron, (in the Erpetologie General, which he is now publishing in conjunction with M. Dumeril,) that there are no large horny tubercles in that species on the hinder part of the thighs. Although the bordered tortoise is far from uncommon in Greece, and in other countries on the shores of the Mediterranean basin, I am compelled to refer to authorities for its structure, as I am not aware of the existence in london of a living or preserved specimen of the animal. Mr. Bell has the only two shells of it that are known to me.Mrs. White's, for the loan of which I am indebted to her kindness, may be a third: but it seems to me, with our present knowledge on the subject, that it must be regarded as distinct.

I propose for it the name of Testudo whitei."

As Bennett states in his footnote, at this time the opinion of Bell was that Whites tortoise represented a specimen of Testudo marginata SCHOEPFF 1792. A view which was obviously still held by J. E. Gray as late as 1870, for in his "Supplement to the Catalogue of Shield Reptiles" (p.11) he writes of it;

Female, or var. Whitei

Testudo whitei, Bennett in White's Selborne.

"A fine adult shell, with the hinder margin moderately expanded, and the caudal shield bent down and slightly inflexed; the sternum flat, the hinder lobe tapering behind, the anal shields being not more than two-thirds the width of the shields before them,; the pectoral shields very short, not above one-fourth the length of the abdominal shields on the inner half, the outer half about double the width and square; the dorsal shields black; the areola varied with yellow; the hinder upper half of the marginal shields varied with yellow; the underside is yellowish white, with a few irregular unequal-sized black spots. Adult female. The tortoise was described in White's 'Selborne', and presented to the Museum in 1858 by Mrs. Christopher, niece of Mr. White."

Gray obviously regarded the White specimen as somewhat unusual, for it is referred to as Testudo marginata var. whitei. In fact, Bennett was entirely correct in his original dismissal of it as a specimen of marginata. Identical errors on the parts of authorities of the undoubted taxonomic abilities of Gray and Bell do, however, serve to demonstrate that these tortoises definitely have been mistaken for marginata - a fact which goes some way to explaining the large number of otherwise inexplicable reports of Testudo marginata encountered in much 19th C. literature on the chelonian fauna of Algeria.
A somewhat puzzling feature of Bennetts description is his failure to refer (in any way) to Linnaeus's Testudo graeca, Testudo pusilla or Testudo tessellata minor africana (Edwards, 1748). Confronted with an enigmatic tortoise, it seems odd that none of these other possibilities was even discussed - particularly as White himself had ventured the opinion that his tortoise was a T. graeca. The probable answer is that Bennett recognised immediately that Whites tortoise was so different from Testudo graeca L. that he did not feel that any question of confusion arose, so he simply did not feel it necessary to mention them or draw comparisons with them. It is also noteworthy that such eminent authorities as Gray and Bell also did not connect this specimen with the Testudo graeca of Linnaeus. The dimensions of the specimens must have suggested that the only really likely candidate was Testudo marginata - an animal which does indeed closely approximate Testudo whitei in size, whereas T. graeca L. manifestly does not.

Conclusions;

Testudo whitei BENNETT 1836 is not as has often been thought a synonym of Testudo graeca L. 1758, but is a full and independent species. Morphological differences between the two races are constant, and T. graeca L. never attain the dimensions reached by T. whitei BENNETT. Early reports of North African tortoises which approach the size of T. marginata SCHOEPFF 1792 may be found to concern T. whitei BENNETT. To date, bibliographic research has revealed no earlier credible description of this species than that published by Bennett in 1836, so his nomenclature Testudo whitei should be regarded as valid. No type locality was specified in Bennett's original publication, but the terra typica of this species is undoubtedly Algiers and its environs, Algeria.

Some synonyms in lit.:

As Testudo marginata SCHOEPFF; Gervais 1836; Gray 1870; Lallemant 1867.

As Testudo ibera PALLAS: Boulenger 1889; Lortet 1888; Johnson 1928.

As Testudo graeca graeca; Flower 1945; Lambert 1982; Loveridge and Williams 1957; Pritchard 1966 and 1979;

Authors note;

The re-discovery of this tortoise changes the entire position regarding the status and nomenclature of the North African members of the genus Testudo. It also raises a number of vitally important questions concerning current population status and conservation. Hitherto, data from T. graeca L. and T. Whitei have not been considered separately. As a result, figures for T. graeca L. are distorted, and figures for T. whitei non-existent. We know next to nothing of the ecology and behaviour in the wild of T. whitei, and have no data whatsoever regarding the current population status of the species. Few surveys of the herpetofauna of Algeria have been published in recent years, and of those that have the picture in respect of the tortoises is not encouraging (Sura, 1987). We do know that the species was heavily exploited commercially (Lambert, 1980) for many years to supply the pet trade in Europe (large numbers being collected for export to France, Germany and the U.K prior to CITES and other export restrictions), but we have no recent data on distribution or numbers. This information is required urgently to assess if further conservation steps need to be implemented in order to secure the species continued survival in its natural habitat.

REFERENCES

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